Unsteady Flow Condition of Centrifugal Pump for Low Viscous Fluid Food

International Journal of Fluid Machinery and Systems


二重反転形小型ハイドロタービンの翼近傍における圧力変動

二重反転形小型ハイドロタービンの翼近傍における圧力変動


PIV Measurement of Inlet and Outlet Flow of Contra-Rotating Small-Sized Cooling Fan

Contra-rotating rotors have been adopted for some of the cooling fans to meet the demand for the high pressure and large flow rate. Therefore, it is important to clarify its inlet and outlet flows by experiments for the high performance and stable operation. PIV measurements were conducted at the design and partial flow rates. In the present paper, the inlet and outlet flow conditions of the contra-rotating small-sized cooling fan with a 40mm square casing are studied by using PIV measurement. Furthermore, improvements of the flow condition and design guideline to increase the performance were discussed based on the experimental results.


Performance and Flow Condition of Cross-Flow Wind Turbine with a Symmetrical Casing Having Side Boards

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10 %) as compared to that of other small wind turbines. In order to improve the performance and flow condition of the cross-flow rotor, the symmetrical casing with a nozzle and a diffuser are proposed and the experimental research with the symmetrical casing is conducted. The maximum power coefficient is obtained as Cpmax = 0.17 in the case with the casing and Cpmax=0.098 in the case without the casing. In the present study, the power characteristics of the cross-flow rotor and those of the symmetrical casing with the nozzle and diffuser are investigated. Then, the performance and internal flow patterns of the cross-flow wind turbine with the symmetrical casings are clarified. After that, the effect of the side boards set on the symmetrical casing is discussed on the basis of the analysis results.


Influence of Spoke Geometry on Performance and Internal Flow of Contra-Rotating Small-Sized Hydroturbine

二重反転形小型ハイドロタービンのスポーク形状が性能と内部流れに及ぼす影響


Internal Flow of Contra-Rotating Small-Sized Hydro Turbine at Maximum Efficiency Flow Rate

二重反転形小型ハイドロタービンの最高効率流量点における内部流れ

Small hydropower generation is one of important alternative energy, and potential of small hydropower is great. Efficiency of small hydro turbines is lower than that of large one. Then, there are demands for small hydro turbines to keep high performance. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance. In this research, experimental apparatus of the contra-rotating small hydro turbine with 60 mm casing diameter was manufactured and performance of it was investigated by an experiment. Efficiency of the contra-rotating small hydro turbine was high in pico-hydro turbines and high efficiency could be kept in wide flow rate range. Unsteady internal flow conditions, which were difficult to measure experimentally, were shown by the numerical flow analysis. Further, pressure distributions and wake interactions with a rotor rotation were clarified. Then, a relation between the performance and unsteady internal flow condition was considered by the experimental and numerical analysis results.


Effects of eccentric vortex on internal flow and performance of a cross-flow fan

クロスフローファンの偏心渦が内部流れと性能に及ぼす影響について

In the internal flow of the cross flow fan, the formation of the eccentric vortex centered on the rotor inner periphery is well known. So far, the relationship between fan shape and performance, and the formation mechanism and behavior of the eccentric vortex have been reported. However, few studies have focused on the relevance of the fan performance and the eccentric vortex. In this paper, the structure, behavior and driving power of the eccentric vortex are investigated. Next, the effect of the eccentric vortex on the performance is considered. As a result, the following becomes apparent. The entrance flow of the cross flow fan is sucked towards the eccentric vortex indicating strong suction pressure, and therefore, the velocity at the rotor inlet becomes non-uniform in the circumferential direction. Because inlet velocity becomes fast in the tongue side which is near the eccentric vortex, the driving power of the eccentric vortex becomes large. By generating swirling flow by the change of an entrance shape and decreasing tongue side velocity by the outward centrifugal force of this turning flow, the eccentric vortex power decreases and high fan efficiency is accomplished. Finally, the high-performance design guideline of the cross flow fan by controlling the eccentric vortex is proposed.


PIV Measurement of Inlet and Outlet Flow of High Pressure and High Flow Rate Small-Sized Cooling Fan

高圧・高風量な小型冷却ファンの入口および出口流れのPIV計測

Data center has been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High pressure and high flow rate cooling fans are used for servers in the data center and there is a strong demand to increase pressure and flow rate of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of high pressure and high flow rate cooling fans. It is important to clarify inlet and outlet flows of it by experiments for high performance and stable operation. PIV measurements of a high pressure and high flow rate cooling fan with 40 mm square were conducted and improvements of the flow condition were discussed by the experimental results.


Study of emulsification mechanism and droplet size estimation in a homogenizer

圧力式ホモジナイザーの乳化作用と液滴径予測に関する研究

A pressure type homogenizer consists of a plunger pump, and a valve part with a narrow channel. It generates effects such as a shear, a turbulent flow and a cavitation between fluid molecules at very short time, and makes a homogeneous emulsification state. If the flow pattern in a valve can be solved in more detail, the more efficient and stabilized emulsification will be attained. However, since it is difficult to measure the size, the pressure and the flow velocity in a narrow gap space by experiment, the details of the mechanism of emulsification by s shear, a turbulent flow, a cavitation and a collision have not been clarified enough. In this research, the size of gap is first calculated from the theoretical equation assumed to be laminar flow, based on the Reynolds number of the gap flow. Next, the pressure, the flow velocity, shearing stress, etc. are calculated. Then, the emulsification mechanism of each part of the valve is clarified by expressing the droplet size as a function of the gap size, the shearing stress and the exit velocity about two kinds of original solutions in which interfacial tension differs. Furthermore, the prediction expression of droplet size obtained by the emulsification is proposed.


Internal Flow of Contra-Rotating Small Hydro-Turbine at Off-Design Flow Rates

二重反転形小型ハイドロタービンの非設計流量点における内部流れ


Internal Flow with Foreign Vegetable Materials in a Contra-Rotating Small Hydro-Turbine

植物性異物混入時における二重反転形小型ハイドロタービンの内部流れ


Unsteady Internal Flow in a Centrifugal Pump for Low Viscous Fluid Food

低粘度流体食品用遠心ポンプの非定常内部流れについて

Fluid machineries for fluid food have been used in wide variety of field i.e. transportation, filling, and improvement of quality of fluid food. Although, flow conditions of these are quite complicated because fluid food is different from water. Therefore, design method based on the internal flow conditions is not conducted. In this research, the centrifugal pump having small number of blade was used to decrease shear loss and keep wide flow passage. In previous studies, it was found that unsteady internal flow condition occurred in a test pump, but those flow phenomena were not clarified. In order to investigate the unsteady internal flow condition in detail, the numerical analysis using low viscous fluid was conducted. In this paper, the unsteady internal flow conditions of centrifugal pump using low viscous fluid were clarified by experimental and unsteady numerical analysis results. In addition to that, the design method based on the internal flow was considered.


Performance Analysis of Mini Centrifugal Pump with Splitter Blades


Study of Emulsification Mechanism in a Pressure Type Homogenizer

圧力式ホモジナイザーの乳化メカニズムに関する研究

Emulsification technique is used in broad fields, such as food, chemistry, and medical treatment, and the range of use has been spreading still more. A pressure type homogenizer consists of a plunger pump and a valve part with a narrow channel. It generates the effects of shear, a turbulent flow and cavitation at very short time, and then makes a homogeneous emulsification state. If the flow pattern in the valve can be solved in more detail, the more effective and stabilized emulsification will be attained. However, since the measurement of the size, the pressure and the flow velocity in a narrow gap space by experiments is difficult, the details of the mechanism of emulsification by the shear, the turbulent flow, the cavitation and a collision have not been clarified enough. In this research, the size of gap is first calculated from the theoretical equation assumed to be laminar flow, based on the Reynolds number of the gap flow. Next, the pressure, the flow velocity, shearing stress, etc. are calculated. Then, the emulsification mechanism of each part of the valve is clarified by expressing the droplet size as a function of the gap size, the shearing stress and the exit velocity.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Performance Characteristics of Small-Sized Cooling Fan with High Pressure and High Flow Rate

高圧・高風量な小型冷却ファンの性能特性について

Data center has been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling fans are used for servers in the data center and there is a strong demand to increase power of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of the high power cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance and internal flow condition to achieve the high performance cooling fans. The performance characteristics of the front and rear rotor of high power contra-rotating small-sized cooling fan is clarified by numerical analysis and design guideline to improve the performance is discussed.


Internal Flow Condition of High Power Contra-Rotating Small-Sized Axial Fan

International Journal of Fluid Machinery and Systems


Unsteady Internal Flow of High Pressure and Large Flow Rate Small-Sized Cooling Fan

高圧・高風量な小型冷却ファンの非定常内部流れについて

Data center has been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High pressure and large flow rate cooling fans are used for servers in the data center and there is a strong demand to increase pressure and flow rate of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of high pressure and large flow rate cooling fans. It is important to clarify unsteady internal flow condition of it for high performance and stable operation. Numerical analysis of high pressure and large flow rate cooling fan with 40 mm square was conducted and unsteady internal flow conditions were discussed in this research.


Unsteady Internal Flow Conditions of Mini Centrifugal Pump with Splitter Blades


Study on a Contra-Rotating Small Hydro Turbine

二重反転形小型ハイドロタービンに関する研究


Performance and Internal Flow Condition of Mini Centrifugal Pump with Splitter Blades

International Journal of Fluid Machinery and Systems


Study on Internal Flow of an Undershot-Type Cross-Flow Water Turbine

下掛け式クロスフロー水車の内部流れに関する研

The aim of this study is to develop an ultralow-head water turbine for an open channel, such as an irrigation channel, in order to effectively use hitherto unused hydropower energies. By focusing on a cross-flow runner, we eliminated the casing and used the application as a water turbine(undershot-type cross-flow water turbine)for an open channel. We investigated the performance and internal flow of the water turbine at a constant flow rate through an experiment and computational fluid dynamics(CFD)analysis. As a result, the following facts became clear. The performance and internal flow of the proposed water turbine with a free surface can be predicted to a certain extent by CFD analysis. At the best-efficiency-point rotational speed, ϑ=21-91° is the first-stage inlet area and ϑ=91-132° is the second-stage outlet area on the outer circumference of a runner. Moreover, on the inner circumference of the impeller, ϑ=48-109° is the first-stage outlet area and ϑ=109-141° is the second-stage inlet area.


クローズド形一枚羽根遠心羽根車に作用する変動流体力の成分分析

クローズド形一枚羽根遠心羽根車に作用する変動流体力の成分分析

日本機械学会論文集(B編)


Study on Contra-Rotating Small-Sized Axial Flow Hydro Turbine


クロスフローファンの入口予旋回流れとその制御

クロスフローファンの入口予旋回流れとその制御

日本機械学会論文集(B編)


Influence of Blade Row Distance on Performance and Flow Condition of Contra-Rotating Small-Sized Axial Fan


低粘度流体食品用遠心ポンプのチップクリアランスが性能と内部流れに及ぼす影響

低粘度流体食品用遠心ポンプのチップクリアランスが性能と内部流れに及ぼす影響


Effects of Rotational Speed Control on Internal Flow of Contra-Rotating Small-Sized Axial Fan

二重反転形小型軸流ファンの回転速度制御が内部流れに及ぼす影響

Small-sized axial fans are used as air cooler for electric equipments. But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices. Contra-rotating rotors were proposed for the improvement of the performance of small-sized axial fans and the advantages of it on the point of view of the performance were confirmed. On the other hand, the contra-rotating small-sized axial fan is operated at off design flow rates and the performance deteriorates at off design flow rates. Therefore, rotational speed control of each front and rear rotor is proposed for the improvement of the performance at off design flow rates in this research. In the present paper, the performance of the contra-rotating small-sized axial fan under the rotational speed control is shown and the internal flow conditions of each rotational speed control method are clarified by the numerical analysis results.


クローズド形一枚羽根遠心ポンプの変動流体力に関する研究

クローズド形一枚羽根遠心ポンプの変動流体力に関する研究

日本機械学会論文集(B編)


Unsteady flow condition of contra-rotating small-sized axial fan


Radial Thrust of Single-Blade Centrifugal Pump


Performance and Internal Flow of High Power Cooling Fan

高出力空冷ファンの性能と内部流れについて

Data center has been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling fans are used for servers in the data center and there is a strong demand to increase power of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of the high power cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance and internal flow condition to achieve the high performance cooling fans. Numerical analysis of a cooling fan with 40 mm square was conducted and influence of tip clearance on performance was investigated experimentally in this research.


開水路に設置したクロスフロー水車に関する研究

開水路に設置したクロスフロー水車に関する研究


Influence of Blade Outlet Angle and Blade Thickness on Performance and Internal Flow Conditions of Mini Centrifugal Pump

International Journal of Fluid Machinery and Systems


翼先端流れに着目した斜流ポンプの不安定特性改善に関する研究

翼先端流れに着目した斜流ポンプの不安定特性改善に関する研究

Instability characteristics generated with partial flow rate in a mixed-flow pump have bad influence during the pump operation. This paper is described on the improvement of instability characteristics in a mixed-flow pump based on flow near blade tip. At first it was examined about the influence of the suction flow channel diameter which gave to performance and internal flow of mixed-flow pumps experimentally. Furthermore, it was examined about influence when it combined control of blade loading distributions near blade tip. As a result, pump efficiency fell at flow rate of the best efficiency a little when we reduced suction flow channel diameter. However, instability characteristics were improved so that a reverse flow developed at the impeller inlet tip side with the decrease of the flow rate slowly. In addition, about 82% head falls of instability characteristics were improved when we combined reduction of suction diameter and the impeller of aft-loading.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Study on Performance and Internal Flow of Fluid Food Pump

流体食品ポンプの性能と内部流れに関する研究

Fluid machineries for fluid food have been used in wide variety of field i.e. transportation, filling and improvement of thequality of fluid food. Although, flow conditions of it are quite complicated because fluid food is different from water.Therefore, the design method based on the internal flow conditions is not conducted. In this research, turbo-pump havingsmall number of blade number was used to decrease shear loss and keep wide flow passage. In this paper, performance andinternal flow conditions of turbo-pump using low viscous fluid were clarified by experimental and numerical analysisresults.


Study on Performance and Flow Condition of Cross-flow Wind Turbine with a Symmetrical Casing

Journal of Fluids Engineering - Transactions of the ASME


Study on Performance and Internal Flow Condition of Mini Turbopump

小型ターボポンプの性能特性と内部流れに関する研究

Mini turbo-pumps which have a diameter smaller than 100 mm are utilized in many fields. It is desirable that the miniturbo-pump design is as simple as possible due to the limitation of the precision for manufacture. But the design method forthe mini turbo-pump is not established. Therefore, we started the research of the mini turbo-pump for the purpose of developmentof high performance mini turbo-pump with simple structure. It is clarified from the numerical results that head andefficiency decrease drastically with the increase of the tip clearance and the flow condition near the tip region is influencedby the leakage flow from the blade tip. In the present paper, the performance of the mini turbo-pump is shown and the internalflow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the tip clearance onthe performance are investigated and high performance rotor design for mini turbo-pump would be considered.


斜流ポンプの内部流れと不安定特性に及ぼす翼端羽根負荷分布の影響

斜流ポンプの内部流れと不安定特性に及ぼす翼端羽根負荷分布の影響

Instability characteristics generated with partial flow rate in a mixed-flow pump have bad influence during the pump operation. In this paper, a method to control blade loading distributions of the mixed-flow pump by a simple and easy method is shown. This method was applied to control of the blade loading distribution of the blade tip in mixed-flow pumps. Furthermore, performance and the internal flow of these pumps were examined experimentally. As a result, head and pump efficiency fell at flow rate of the best efficiency in the impeller of aft-loading, but the instability characteristics were largely improved. In addition, a reverse flow suddenly developed at the impeller inlet tip side with the decrease of the flow rate in the impeller of fore-loading, but it was shown clearly that the reverse flow did not suddenly develop in the impeller of aft-loading.

日本機械学会論文集(B編)


小型ターボポンプの羽根出口角が羽根車性能に及ぼす影響

小型ターボポンプの羽根出口角が羽根車性能に及ぼす影響


The Effect of Blade Outlet Angle on Performance and Internal Flow Condition of Mini Turbo-Pump


らせん状吸込流路を有する一枚羽根遠心ポンプのラジアルスラストに及ぼす羽根出口幅の影響


二重反転形小型軸流ファンの性能特性と内部流れに関する研究

二重反転形小型軸流ファンの性能特性と内部流れに関する研究

Small-sized axial fans are used as air cooler for electric equipments. But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices. Therefore, higher rotational speed design is conducted although, it causes the deterioration of efficiency and the increase of noise. Then the adoption of contra-rotating rotors for the small-sized axial fan is proposed for the improvement of performance. In the present paper, the performance curves of the contra-rotating small-sized axial fan with 100mm diameter are shown and the velocity distributions with the designed flow rate at the inlet and the outlet of each front and rear rotors are clarified with experimental results. Furthermore, the flow conditions between front and rear rotors of the contra-rotating small-sized axial fan are investigated by numerical analysis results and higher performance design of the contra-rotating small-sized axial fan are discussed.

日本機械学会論文集(B編)


Performance and Flow Condition of Contra-rotating Small-sized Axial Fan at Partial Flow Rate

International Journal of Fluid Machinery and Systems


未加硫ゴムの充填過程における流れの現象と不均一な充填

未加硫ゴムの充填過程における流れの現象と不均一な充填

Rubber products like oil seal are produced by vulcanization molding and the vulcanization molding of rubber product is performed by past experience, trial and error. It is important issues to decrease the product cost, reduce defective products and solve the environmental problems by saving natural resources. If the vulcanization moldings of rubber products are reappeared by computer simulation, it is very useful and it could contribute to solve the above problems. In order to reduce surplus rubber and defective product, numerical analysis of flow phenomena of unvulcanized rubber was performed using commercial software FIDAP. In several types of rubber product models, the analysis was conducted taken the characteristic of visco-elasticity fluid obtained by experiment, without considering the effect of the heat. And experiments were conducted for the comparison of numerical results and actual phenomena. In the experiment, vulcanization process was stopped by arbitrary interval. Then the filling state and the shape of the rubber at each interval are observed in numerical and experiment results. The results showed that the filling state of numerical results represented good agreement with the experimental results. And it was clarified from the numerical analysis that shear stress acted when the unvulcanized rubber flowed in narrow channel and there was the relation between pressure and velocity. In the present paper, the flow phenomena under the condition of the compression molding are shown and the optimum flow conditions are discussed from the numerical results. Furthermore mechanism of occurrence of defective products is considered with the experimental and the numerical results.

日本機械学会論文集(B編)


小型軸流ファンへの二重反転形羽根車の採用について

小型軸流ファンへの二重反転形羽根車の採用について

Small-sized axial fans are used as air cooler for electric equipments. But there is a strong demand for higher power of fan according to the increase of quantity of heat from electric devices. Therefore, higher rotational speed design is conducted although, it causes the deterioration of the efficiency and the increase of noise. Then, the adoption of contra-rotating rotors for the small-sized axial fan is proposed for the improvement of performance. In the present paper, the experimental results of a conventional small-sized axial fan with 100 mm diameter are shown and the important points to adopt the contra-rotating rotors are considered with these results. Furthermore, the performance and the flow field of the contra-rotating smallsized axial fan are clarified by the numerical analysis results and the advantages of the adoption of the contra-rotating rotors for the small-sized axial fan are discussed.


羽根出口角の異なる一枚羽根遠心ポンプの損失解析

羽根出口角の異なる一枚羽根遠心ポンプの損失解析

Single-blade centrifugal pump is used as a sewage pump widely. However, hydraulic losses increase because the impeller width is large as for single-blade centrifugal pump. It is extremely complicated, besides, because the internal flow of single-blade centrifugal pump changes greatly by an impeller position and changes by the flow rate. Therefore, a quantitative prediction and the elucidation of the generation mechanism of unsteady hydraulic losses are expected to make this kind of pump high efficiency. In this study, loss analysis was performed about two kinds of single-blade centrifugal impeller with different impeller outlet angle. As a result, the effect of the impeller outlet angle which gave it to performance and hydraulic losses was clarified. Furthermore, the momentary behavior of performance and hydraulic losses was shown, and their relations with the impeller inlet and outlet flow became clear.

日本機械学会論文集(B編)


Performance and Flow Condition of Small-Sized Axial Fan and Adoption of Contra-Rotating Rotors


Design Method for Single-Blade Centrifugal Pump Impeller

The sewage pumps are demanded a high pump efficiency and a performance in passing foreign bodies. Therefore, the impeller used by these usages requires the large passed particle size (minimum particle size in the pump). However, because conventional design method of pump impeller results in small impeller exit width, it is difficult to be applied to the design of single-blade centrifugal pump impeller which is used as a sewage pump. This paper proposes a design method for single-blade centrifugal pump impeller. As a result, the head curve of the impeller designed by the proposed design method satisfied design specifications, and pump efficiency was over 62% more than conventional single-blade centrifugal pump impeller. By comparing design values with CFD analysis values, the suction velocity ratio of the design parameter agreed well with each other, but the relative velocity ratio did not agree due to the influence of the backflow of the impeller entrance.


ケーシング幅が二重反転多翼ファンの性能に及ぼす影響

ケーシング幅が二重反転多翼ファンの性能に及ぼす影響

A sirocco fan using contra-rotating rotors in which an inner rotor was settled inside the sirocco fan rotor and each rotor rotated in an opposite direction was proposed for the purpose of getting the higher pressure and making the structure of a sirocco fan compact more. If the high discharge pressure is obtained with the adoption of the contra-rotating rotors, it could be used for various purposes. Pressure coefficient of the sirocco fan with contra-rotating rotors was 2.4 times as high as the conventional sirocco fan and the maximum efficiency point of contra-rotating rotors shifted larger flow rate than the conventional sirocco fan. On the other hand, it was clarified from the flow measurement results that the larger back flow region than conventional one occurred at the shroud of the casing in the case of contra-rotating type and this would induce decrease of the efficiecy. In the present paper, the performance of the conventional sirocco fan and the sirocco fan with contra-rotating rotors are shown and the internal flow field at the outlet of the outer rotor of both cases is clarified Then, the effect of casing width on the performance and the internal flow field is investigated and the casing width which would be suitable for the contra-rotating type would be discussed.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


一枚羽根遠心ポンプのラジアルスラストに及ぼす羽根出口角の影響

一枚羽根遠心ポンプのラジアルスラストに及ぼす羽根出口角の影響

Single-blade centrifugal pump is widely used as a sewage pump. However, a single-blade is acted on by a large thrust during the pump operation because of the geometrical asymmetry of the impeller. Therefore when the reliability of the pump is secured, it is necessary to grasp a radial thrust quantitatively and elucidate the behavior and the dominant factors. This study investigated the radial thrust acting on two kinds of single-blade centrifugal impeller of different impeller outlet angle by an experiment and CFD analysis. Furthermore, as for the radial thrust to act on two kinds of impellers, the radial thrust was modeled by a combination of three components, unsteady, momentum and pressure components. As a result, the effect of the impeller outlet angle on the radial thrust and the each divided components was clarified.

日本機械学会論文集(B編)


The shapes of valves and emulsification action in a homogenizer

ホモジナイザーのバルブ形状と乳化効果

The homogenizer basically consists of a high-pressure plunger pump usually with triple plungers to minimize pressure fluctuations and a homogenizing valve with a narrow gap. However, the flow within the homogenizing valve is not clarified theoretically. In this paper, the influence of shape modification of the homogenizing valve was investigated in the emulsification action. The experiments using a small homogenizer are conducted. We studied the influence of the flow pattern (pressure distributions, shear stress) on the droplet size distribution obtained in the experiment, and investigated the relation between the shear flow and the emulsification action in the homogenizing valve. In this experiment, two valve types (sharp type and flat type) were applied. The pressure drop in the valve and the parallel gap part length were changed. The droplet size distribution results obtained in the emulsification tests could be analyzed based on the average value of the wall shear stress in the parallel gap part through the above experiments and calculation results.

圧力式乳化機は，安定した乳化が得られるため幅広い分野で利用されている．しかし，圧力式乳化機では，せん断・乱流・キャビテーションが同時に引き起こされ，乳化作用に対し重要度が高いものから，せん断・乱流・キャビテーションをランク付けすることは非常に難しい．圧力式乳化機の均質バルブ内の流れについて研究されているが，おもに圧力の違いで検討されており，依然として明らかにされていない部分がある．そこで，本研究では，小型の圧力式ホモジナイザーの均質バルブ形状を変更し，形状の違いによる影響について調査した．また，バルブ隙間の流れが放射状の層流であるとした計算式からバルブ隙間を算出し，均質バルブ内の圧力・せん断応力の代表値を導いた．さらにせん断応力の代表値による計算結果と実験による乳化後の粒子径を比較し，その代表値による乳化作用の整理式を提案できた．


Study on Performance Improvement of Cross-Flow Wind Turbine with Symmetrical Casing

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10 %) as compared to that of other small wind turbines. In order to improve the performance and the flow condition of the cross-flow rotor, symmetrical casings with a nozzle and a diffuser are proposed and experimental research with two types of symmetrical casings is conducted. The maximum power coefficient is obtained as Cpmax = 0.17 for casing 2 and Cpmax=0.098 for casing 1. In the present study, power characteristics of the cross-flow rotor and those of the symmetrical casings with the nozzle and the diffuser are investigated. Then, the performance and internal flow patterns of the cross-flow wind turbine with the symmetrical casings are clarified. After that, the effect of the symmetrical casings on the performance of the turbine is discussed on the basis of the analysis results.


圧力式ホモジナイザーにおける内部流れと乳化効果の研究

圧力式ホモジナイザーにおける内部流れと乳化効果の研究

The homogenizer is extensively used to emulsify, disperse the products in various industrial fields including: food, chemical, pharmaceutical and biotechnology. The homogenizer basically consists of a high-pressure plunger pump usually with triple plungers to minimize pressure fluctuations and a homogenizing valve with a narrow gap. However, the flow within the homogenizing valve is not clarified theoretically. If the flow pattern within the homogenizing valve could be solved, a more efficient and stabilized emulsification could be carried out. In this paper, the influence of shape modification of the homogenizing valve was investigated in the emulsification effect. The experiments using a small homogenizer are conducted. We studied the influence of the flow pattern (velocity distributions, pressure distributions, shear stress) on the drop size distribution obtained in the experiment, and investigated the relation between the average value of wall shear stress and the emulsification effect in the homogenizing valve. The flow patterns were investigated using a Computational Fluid Dynamic model of the flow in the homogenizing valve. The purpose of this paper is to clarify the effects of differences in the shapes of valves on the results of emulsification.

日本機械学会論文集(B編)


Internal Flow Measurement with LDV at Design Point of Contra-Rotating Axial Flow Pump

The adoption of the contra-rotating rotor has been proposed in response to a demand for the axial flow pump with higher specific speed. The internal flow field and blade rows interactions between front and rear rotors should be considered in the design for higher performance and more stable operation, but has not been clarified yet. The flow field in contra-rotating axial flow pump was measured at various flow rates with the LDV and wall pressure measurements. In the present paper, the experimental and numerical results in the flow field between front and rear rotors are shown at the design flow rate and the flow behaviors are discussed, related on blade loading, blade tip leakage flow, wake and blade rows interaction.


Loss Analysis of a New Type of Sewage Pump

Authors have been proposing a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. And pump performance, internal flow and behavior of the radial thrust have been clarified by LDV measurement and CFD analysis. However, hydraulic design of pumps is integral calculus operation whereas flow analysis is differential calculus operation. Therefore, even if complicated internal flow was clarified by CFD analysis, it is difficult to improve pump performance if the cause and outbreak mechanism of each hydraulic loss were not clarified. This paper proposes loss analytical method of this pump equipped with a single blade impeller. As a result of having compared experimental values and CFD analysis values with loss analysis values about the head curve, they almost matched in a wide range of flow rates. When the flow flows backward to the impeller from the volute casing, the hydraulic loss becomes small in an appearance, but the power loss becomes excessive and the pump efficiency decreases.


A Study on Internal Flow in a New Type of Sewage Pump (2nd Report, Influence of Impeller Blade Loading and Volute Casing)

Sewage pumps are designed with a wide flow channel by, for example, sacrificing some efficiency and reducing the number of blades, in order to prevent plugging with foreign bodies. Authors have been proposing a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. This sewage pump impeller has a structure in which the suction flow channel of closed type non-clog pump is wound in a helical spiral. The focus of this research was to investigate internal flow in this single blade sewage pump impeller by LDV measurement and CFD. As a result of having examined influence of impeller blade loading and volute casing, it clearly indicated the following facts. As well as influence of impeller blade middle loading and influence of the secondary flow, by increase of slip by influence of volute casing, static pressure and total pressure suddenly decrease together towards the end from impeller blade middle neighborhood.


A Study on Internal Flow in a New Type of Sewage Pump (1st Report, Comparison between Experiment and CFD Calculation)

Sewage pumps are designed with a wide flow channel by, for example, sacrificing some efficiency and reducing the number of blades, in order to prevent plugging with foreign bodies. Authors have been proposing a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. This sewage pump impeller has a structure in which the suction flow channel of closed type non-clog pump is wound in a helical spiral. The focus of this research was to investigate internal flow in this single blade sewage pump impeller. The results clearly indicated the following facts. As a result of having compared experimental results by LDV with calculated results by CFD, there is the difference about the radial component of absolute velocity, but agrees about pump performance and the tangential component comparatively well. A flow to circulate through in the impeller again is accepted by an experiment, and the sign is accepted by CFD in a specific impeller position.


一枚羽根遠心ポンプのラジアルスラスト

一枚羽根遠心ポンプのラジアルスラスト

Single-blade centrifugal pump is used as a sewage pump widely. However, single-blade centrifugal pump impeller is acted on a big radial thrust during the pump operation because the impeller is an asymmetry geometrically. Therefore when the reliability of the pump is secured, it is necessary to grasp a radial thrust quantitatively and elucidate the behavior and outbreak mechanism. This study investigated the radial thrust acting on single-blade centrifugal impeller by an experiment and CFD analysis. As a result, the behavior of the radial thrust with the flow rate change was clarified. Furthemore, the radial thrust was divided to an unsteady component, a momentum component and a pressure component by applying unsteady conservation of momentum to this impeller. The grand total of these components accorded with the radial thrust that calculated by direct CFD analysis well. And the behavior of each divided component was shown. In addition, the effect of those components that gave to the radial thrust was clarified.

日本機械学会論文集(B編)


A Study of Performance and Internal Flow in a New Type of Sewage Pump

International Journal of Fluid Machinery and Systems


一枚羽根遠心羽根車の設計法に関する研究

一枚羽根遠心羽根車の設計法に関する研究

The sewage pump are demanded a high pump efficiency and a performance in passing foreign bodies. Therefore, the impeller used by these usages demands the large passing particle size (minimum particle size in the pump). However, because conventional design method of pump impeller calculates impeller exit width small, it is difficult to apply to single-blade centrifugal pump impeller which is used as a sewage pump. This paper proposes design method for single-blade centrifugal pump impeller. As a result, the head curve of the impeller by this design method satisfied a design point, and pump efficiency was over 62% more than conventional single-blade centrifugal pump impeller. Having compared design values and CFD analysis values, the suction velocity ratio of the design parameter accorded well, but the relative velocity ratio did not agree by the influence of the backflow of the impeller entrance.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Internal flow of a new type drying equipment

新型乾燥装置の内部流動について

The flow conditions of a new dryer for by-product of tofu proposed in the previous paper are examined. Its drying capacity is relatively small and to know the internal flow is necessary to develop larger capacity machines. Firstly, the interior of drying drum and classifying chamber were observed using high speed video. Wet materials returning from upper chamber are colliding with the materials and ceramic balls moving along the surface of the drying drum entrained in the hot air and dispersed. In the classifying chamber counterclockwise circulating flows are formed. Then numerical simulation was carried out for the flow of this dryer using FLUENT. Necessary nodes were about 800,000 to describe the whole machine. Obtained path lines are almost consistent with the video images showing the validity of the simulation method. To get the suitable geometry for 5 times larger machine, flow conditions were compared for three types of geometry of the entrance to classifying chamber and the best geometry was determined. The chamber height was then determined so that the velocities at the ceiling are below 3 m/s to avoid adhesion of the wet materials to the wall. Based on the obtained results 300 kg/h machine was build and it was successfully operated.

前報で提案した50 kg/hの処理能力をもつ乾燥器の内部の流れの観測と解析をまず行った．高速度ビデオにより，乾燥ドラム内でのおからの分散状況や，分級チャンバー内の左回りの大きな旋回流が観測できた．解析により，ドラム内には内壁に沿って高速気流部があり，その内側に右回りの循環流が形成され，じゃま板の反対側には左回りの循環流があること，また，チャンバー内には左回りの大きな循環流があることが確認できた．解析結果は，実際の内部流れの画像や流速分布の測定値と良く対応しており，本解析は有効であることがわかる．そこでこれを用いて，乾燥ドラムを5/4倍にして，処理量を5倍とするためには，チャンバー入口を比較した3種類の内Bタイプとし，さらにチャンバー高さを500 mm高くするとよいことがわかった．得られた結果に基づいて試作した乾燥器により，およそ300 kg/h程度まで良好におからを乾燥できることがわかった．


Drying performance of a new type drying equipment

新型乾燥装置の乾燥性能について


汚水用新型ポンプの損失解析

汚水用新型ポンプの損失解析

日本機械学会論文集(B編)


The Study on The Flow Phenomena of Unvulcanized Rubber in Process of Filling

未加硫ゴムの圧縮成形時における流動現象に関する研究

Rubber products, e.g. oil seal, are produced by vulcanization molding and the vulcanization molding of rubber product is performed by past experience, trial and error. In order to reduce surplus rubber and defective product, numerical analysis of flow phenomena of unvulcanized rubber was performed using FIDAP. The analysis was conducted taken the characteristic of unvulcanized rubber obtained by experiment, without considering the effect of the heat. The results showed that the filling state of numerical results represented good agreement with the experimental results. And it was clarified from the numerical results that high shear stress acted during unvulcanized rubber fill up to a narrow channel such as side surface of metal insert. In this paper, the flow phenomena under the condition of vulcanization molding are shown and the optimum flow condition would be discussed with experimental and numerical results.

日本機械学会論文集(B編)


汚水用新型ポンプの内部流れに関する研究(第2報，羽根負荷とボリュートケーシングの影響)

Sewage pumps are designed with a wide flow channel by, for example, sacrificing some efficiency and reducing the number of blades, in order to prevent plugging with foreign bodies. Authors have been proposing a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. This sewage pump impeller has a structure in which the suction flow channel of closed type non-clog pump is wound in a helical spiral. The focus of this research was to investigate internal flow in this single blade sewage pump impeller by LDV measurement and CFD. As a result of having examined influene of impeller blade loading and volute casing, it clearly indicated the following facts. As well as influence of impeller blade middle loading and influence of the secondary flow, by increase of slip by influence of volute casing, static pressure and total pressure suddenly decrease together towards the end from impeller blade middle neighborhood.

日本機械学会論文集(B編)


Study on Performance Improvement of Cross-Flow Wind Turbine with Symmetrical Casing

対称形ケーシングによるクロスフロー風車の高性能化に関する研究

Cross-flow wind turbine has a characteristic of high torque coefficient at low tip speed ratio. Therefore, it is good for the self-starting. Furthermore, it is low noise and superior to stability so that it attracts attentions as the city type small-sized wind turbine for urban district. But the maximum power coefficient is extremely low as 10% compared with other small-sized wind turbines. In order to improve the performance and the flow condition of cross-flow rotor, a symmetrical casing with a nozzle and a diffuser was proposed and experimental research with two kinds of symmetrical casings was conducted. The maximum power coefficient was obtained as C_<pmax>=0.17 for the casing 2, however as C_<pmax>=0.098 for the casing 1. In the present paper, power characteristics of cross-flow rotor and one of a symmetrical casing with a nozzle and a diffuser were investigated. Then the performance and internal flow field of a cross flow wind turbine with the symmetrical casing were clarified. After that, the effect of the symmetrical casing on performance would be discussed with these results.

日本機械学会論文集(B編)


汚水用新型ポンプの内部流れに関する研究(第1報，実験と数値解析との比較)

汚水用新型ポンプの内部流れに関する研究(第1報，実験と数値解析との比較)

日本機械学会論文集(B編)


Internal Flow Measurement with LDV at Design Point of Contra-Rotating Axial Flow Pump

二重反転形軸流ポンプにおける設計流量点流れのLDV計測

The adoption of the contra-rotating rotor has been proposed in response to a demand for the axial flow pump with higher specific speed. The internal flow field and blade rows interactions between the front and rear rotors should be considered in the design for higher performance and more stable operation, but has not been clarified yet. The flow field in contra-rotating axial flow pump was measured at various flow rates with the LDV and wall pressure measurements. In the present paper, the experimental and numerical results in the flow field between front and rear rotors are shown at the design flow rate and the flow behaviors are discussed, related on blade loading, blade tip leakage flow, wake and blade rows interaction.

日本機械学会論文集(B編)


Performance and Internal Flow of Sirocco Fan Using Contra-Rotating Rotors


Laminar-Turbulent Transition of a Boundary Layer Induced by a Single Roughness Element in an Inlet Region of a Circular Pipe Flow --- 定常乱流領域の発達過程

円管助走部境界層の単一突起による遷移 --- 定常乱流領域の発達過程

円管助走部境界層の乱流遷移に関する実験的研究である．単一突起を設置することによって下流に形成される定常な乱流領域の平均·変動速度を熱線風速計を用いて測定した．乱流領域の輪郭線は平面に展開するとくさび形である．くさびの頂点は突起位置に一致し，突起直後は直線であるが，次第に外側に向かって曲がる．これは平板上の乱流くさびと同様である．また広がり角も，同程度のレイノルズ数における平板上の乱流くさびと同程度である．乱流領域内の速度変動は中心線上で最大にはならず，周囲の層流領域との界面で最大になる．そこでの乱流領域内部の速度変動は乱流領域中心部よりも大きい．

日本機械学会論文集(B編)


A Study on a New Type of Sewage Pump (Internal Flow and Radial Thrust)

汚水用新型ポンプに関する研究(内部流れとラジアルスラスト)

Sewage pumps are designed with a wide flow channel by, for example, sacrificing some efficiency and reducing the number of blades, in order to prevent plugging with foreign bodies. This paper proposes a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. This sewage pump impeller has a structure in which the suction flow channel of closed type non-clog pump is wound in a helical spiral. The focus of this research was to investigate pump performance, internal flow and radial thrust in this single blade sewage pump impeller. The results clearly indicated the following facts. The developed sewage pump impeller had high efficiency and exhibited high efficiency over a wide range of flow rates. Internal flow of this pump is very complicated, and a state of internal flow largely changes when flow rate changes, and force which is non-uniform in the circumferential direction is applied to the impeller.


汚水用新型ポンプ に関する研究

Sewage pumps are designed with a wide flow channel by, for example, sacrificing some efficiency and reducing the number of blades, in order to prevent plugging with foreign bodies. However, the behavior of foreign bodies which actually flow into a pump is extremely complex, and there are questions about whether the presumed foreign matter will actually pass through. This paper proposes a new type of sewage pump impeller designed to further improve pump efficiency and performance in passing foreign bodies. This sewage pump impeller has a structure in which the suction flow channel of closed type nonclog pump is wound in a helical spiral. The focus of this research was to investigate pump performance and radial thrust in this single blade sewage pump impeller. The results clearly indicated the following facts. The developed sewage pump impeller had high efficiency and exhibited high efficiency over a wide range of flow rates. When experimental and calculated values of radial thrust were compared at the best efficiency point flow rate, both the radial thrust size and direction almost matched. It is effective to reduce radial thrust fluctuating component by added mass.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Pressure Recovery in a Centrifugal Blower Casing

The rate of circulating flow passing through the tongue division and the pressure recovery in the casing are investigated in a centrifugal blower, which has no diffuser and large tongue clearance. At the design point, the ratio of circulating flow rate to total flow rate at the scroll end is about 45 percent, and the pressure recovery in the scroll is about 45 percent. As the remaining 55 percent of the pressure recovery in the casing is recovered in the section between the scroll end and exit duct, this section acts as a high-performance diffuser. It is concluded that the centrifugal force produced by the secondary flow and boundary layer suction are the main causes of the large pressure recovery. Moreover, it is found that the flow conditions from the scroll toward the exit duct are closely related to the low flow rate characteristics of the blower.

JSME International Journal, Series B: Fluids and Thermal Engineering


Performance and Internal Flow of Cross-Flow Fan with Inlet Guide Vane

The effect of angle and length of the inlet guide vane on the performance of the crossflow fan was examined. By installing guide vane of one sheet in tongue division side in the suction region, the performance of the cross-flow fan becomes more high pressure and high efficient than the case without the guide vane. The prerotation of the inlet flow which is counter directional with the rotation of the rotor is generated by the guide vane. In the high flow region, the high pressure and high efficiency are obtained since the suction cascade work increases by the prerotation of the flow, and since the leading edge separation of the suction cascade is more avoided to high flow. Moreover, in the low flow region, it is possible to suppress the circulating flow in scroll side in the rotor suction inlet. Therefore, the high efficiency is obtained in the low power compared to the result without the guide vane.


Quasi-Three-Dimensional Analysis of Cavitation in an Inducer

インデューサに生じるキャビテーションについて準三次元流れ解析を示した．流面における解析では交互翼キャビテーションをシミュレートできる特異点法を用い，平板型ヘリカルインデューサに対して解析を行い，キャビテーションに与える流れの三次元性の影響を明らかにした．

Journal of Fluids Engineering - Transactions of the ASME


Study on Performance and Internal Flow of Cross-Flow Wind Turbine

クロスフロー風車の性能と内部流れに関する研究

都市型小形風車として注目されるクロスフロー風車について，その出力係数が10%と低い理由を明らかにし，円筒型ケーシングを用いてその出力係数を約2．0倍に増大させるとともに，その時のケーシング形状，内部流れについて明かにした．


Quasi Three-dimensional Analysis of Cavitation in an Inducer

インデューサに生じるキャビテーションの準三次元解析

インデューサに生じるキャビテーションについて子午面上の流れに対する解析と回転対称な流面におけるキャビテーション発生下の流れの解析を組み合わせた準三次元解析法を提案し，キャビテーションに与える流れの三次元性の影響を明らかにした．

日本機械学会論文集(B編)


Optimization of Meridional Flow Channel Design of Pump Impeller

羽根車子午面流路形状に勾配法を用いた最適化手法によって高効率羽根車を設計する新しい手法を提案したもので，ポンプ性能試験からその妥当性について示した．

International Journal of Rotating Machinery


Properties of a Turbulence Wedge Which Develops from a Single Roughness Element in a Flat Plate Laminar Boundary Layer

平板層流境界層内の単一突起から発達する乱流くさびの特性

A turbulence wedge that develops downstream from a single roughness element placed in a laminar boundary layer on a flat plate was experimentally investigated. Streamwise vortices, development mechanisms of the wedge in the wall-normal and spanwise directions and development process of the turbulent quantities in the downstream were clarified. Many streamwise vortices appear within the wedge just behind the roughness. Further downstream, on the other hand, a pair of streamwise vortices are found on both interfaces between the wedge and the outer laminar region. The development mechanism of the wedge in the spanwise direction may be governed by the streamwise vortices ; the mechanism in the spanwise direction is different from that in the wall-normal direction. The fluctuating velocities and the Reynolds stresses just behind the roughness are larger than those of the developed turbulent boundary layer because of the many streamwise vortices. Further downstream, they more closely resemble those in the developed turbulent boundary layer.

層流境界層の乱流遷移に関する実験的研究である．乱流くさび領域の平均·変動速度を熱線風速計とV型，X型熱線プローブを用いて測定した．突起直後の断面においてはくさび内に多数の縦渦が存在し，突起からある程度下流に進んだ断面内においては，くさびと周囲の層流領域との界面に一対の縦渦が存在した．乱流のときは，よりくさびの外側に向かうような横方向運動が存在し，これによって乱流くさびは外側に広がることがわかった．この横方向への発達機構には縦渦が影響を与えていると考えられ，境界層厚さ方向と横方向間では発達機構は異なる．突起直後における変動速度，レイノルズ応力は，発達した乱流境界層の分布よりも大きな値を示した．これは突起直後の多数の縦渦によるものと考えられた．またこれらの値の下流方向への変化より，下流に行くに従って乱流が発達することが示された．

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


唐みファンの羽根車出口部近傍の流れに関する研究(第3報，羽根車近傍の静圧等値面と吸込口·吐出し口近傍のパーティクルによる一考察)

唐みファンの羽根車近傍の流れを数値シミュレーションと実験によって検討し，パーティクルによる追跡から吐出し口近傍の非定常な三次元流れを解明した．

日本機械学会論文集(B編)


Theoretical Analysis of Unsteady Fluid Forces Working on Inducer Blades Under Rotating Cavitation

旋回キャビテーション発生下のインデューサ翼に作用する非定常流体力の解析

Rotating cavitation is one of the flow instabilities associated with cavitation, which has been a severe problem for the development of turbopumps of liquid rocket engines because of causing the destructive super-synchronous shaft vibration. Recently, it is argued that rotating cavitation might also induce large repetitive stresses on blades in accordance with the unsteady pressure due to the significant change of cavitating regions. This paper describes about the theoretical prediction of unsteady blade forces working on the cavitating inducer under rotating cavitation. Unsteady pressure distributions and a lift force for a 2-dimensitional flat plate cascade under rotating cavitation are calculated by the linearized free streamline theory based on the unsteady closed cavity model and singularity method.

旋回キャビテーション発生時にインデューサ翼に働く非定常流体力および非定常翼面圧力分布を特異点法を用いて解析する方法を示した．

日本機械学会論文集(B編)


Study on Internal Flow Near the Impeller Outlet of a Winnowing Fan (2nd Report, Discussion of a Impeller with Forward-Inclined Blades by Computational Fluid Dynamics)

唐みファンの羽根車出口部近傍の流れに関する研究(第2報，CFDを用いた前向き羽根に関する一考察)

Because of strong 3-dimensional flow, it is difficult to produce a uniform flow or improve efficiency with winnowing fans. Through experiments with various types of impellers, it was found in an earlier study that a forward-inclined impeller could produce a uniform flow and improve efficiency. It was then reported in a subsequent study aimed at identifying the mechanism behind this, in which the relationship between velocity and static pressure in an impeller of small inclination angle was examined from the perspective of flow, that flow analysis was effective towards estimating inconsistent flow characteristics. Based on these findings, this project was designed to measure and analyze flow characteristics in a forward-inclined impeller. It was found that forward-inclined impellers have many regions of circulating flow and that the mainstream which moves to the outlet is narrow in effective area. As a result, velocity increases and discharge blow rapidly expands within a short distance. Therefore, good static pressure recovery is obtained.

唐みファンにおいて前向き傾斜羽根が羽根車出口部近傍の流れに及ぼす影響を検討した結果，前向き羽根ではスクロール舌部で再循環領域が拡大するため，吐出し流速が大きくなり，短い距離で静圧回復することを示した．

日本機械学会論文集(B編)


Study on Flow Near the Impeller Outlet of a Winnowing Fan (1st Report, The comparisons of the Flow between Experiments and CFD)

唐みファンの羽根車出口部近傍の流れに関する研究(第1報，羽根周辺の流れについてのCFDと実験値との比較)

The winnowing fan used for head feeding type combines draw in air along the axis from the inlet of both sides, and then radially discharges it into scroll. Therefore, the internal flow of this fan shows a strong three-dimensionality and the efficiency is low. In order to improve the efficiency and make the axial distribution of discharge flow uniform, the experimental and numerical investigations were carried out. Numerical results using CFD agree well with experimental ones for the mean flow. It is found that this numerical simulation method is useful for investigation of the effect of blade and casing configurations. Moreover unsteady flow conditions in the impeller though rotations are shown. For example, in the impeller, a vortex formed around the leading edge of the blade, grows connect with another one, reduce and disappear.

コンバインに用いられる唐みファンの羽根車内の流れについてCFD∼得られた結果と実験値が一致し，羽根車内の流れは三次元性が強いこと及び羽根の前縁を起点として渦が発生し羽根車の回転に伴って，渦の成長，結合，減少，消滅の過程を繰り返していることを示した．

日本機械学会論文集(B編)


Study on Reverse Running Pump Turbine (Radial Thrust and Runaway Speed Characteristics)

ポンプ逆転水車に関する研究(ラジアルスラストと無拘束速度特性)

Directly applying power generation technlogy for large-scale hydraulic turbines to a small hydraulic power generation system inevitably results in high costs. Consequently, technology specific to small hydraulic power generation must be developed. For example, a technology to use reverse running pump turbines, wherein mass-produced centrifugal pumps are operated in reverse rotation to obtain power, has been gaining popularity. The 1 st report gave the detailed test results on grasping the turbine characteristics and clarifying the internal flow. On this research, the radial thrust in the turbine mode and at the runaway speed condition was measured and this was evaluated comparing with the measuring data of distributions of circumferential velocity and static pressure at runner inlet and outlet, then the radial thrust tactor Kr was obtained. In addition to this, detailed experiments on the internal flow at the runaway speed condition were carried out to clarify the runaway speed characteristics, further the possibility of predicting the runaway speed characteristics was studied.

ポンプ逆転水車のラジアルスラストと無拘束速度特性について検討し，水車運転時のラジアルスラスト係数は，ポンプ締切り運転時の係数0．36より小さいことを示した．また落差一定の場合の無拘束状態と最高効率点における回転数比，流量比を定めるとともに無拘束速度状態におけるランナ入口，出口の流れを明らかにした．

日本機械学会論文集(B編)


ポンプ逆転水車に関する研究

ポンプ逆転水車に関する研究

小水力発電用水車として汎用の渦巻きポンプを逆転して運転するポンプ逆転水車について詳細な実験を行い，水車特性の把握と内部流れの解明，ポンプ特性から水車特性の予測，性能向上と適用範囲の拡大について検討した．

日本機械学会論文集(B編)


偏心した吸込ノズルをもつ多翼ファンの性能に関する研究

偏心した吸込ノズルをもつ多翼ファンの性能に関する研究

適切な弦節比の羽根車を用い，偏心した吸込ノズルをスクロール吐出し口から離れたスクロール巻始め側に取付けた場合には偏心なしの場合に比べ高い吐出し圧力が得られることを示すとともに，羽根車を一度通り抜けシュラウド隙間を通って羽根車入口に再循環する流れがこの圧力上昇に重要な役割を果たしていることを明らかにした．

日本機械学会論文集(B編)


唐みファンの性能と内部流れに関する研究

唐みファンの性能と内部流れに関する研究

本論文は，軸方向長さが長いプレートファンを用いるコンバイン用の唐みファンにおいて，前向き羽根を用いることで高圧力，高効率が得られファンの小型化が可能であることを示すとともに，ファン出口の軸方向の速度分布の一様化が図れることを詳細な実験によって明らかにした．

日本機械学会論文集(B編)


魚類移送用斜流ポンプ羽根車内の流れに関する研究

魚類移送用斜流ポンプ羽根車内の流れに関する研究

本論文は，魚類移送用として開発した厚翼の二枚羽根斜流ポンプ羽根車内の流れを一次元レーザドップラー流速計を用いて三次元的に計測するとともに特異点法を用いた準三次元流れ解析を行い，両者の値がかなり良く一致することを示した．

日本機械学会論文集(B編)


入口案内羽根による貫流ファンの高性能化に関する研究

入口案内羽根による貫流ファンの高性能化に関する研究

高圧力係数を持つ貫流ファンを開発するため入口案内羽根が内部流れや，ファン性能に及ぼす影響を検討した．入口案内羽根によって流入流れを制御し，回転と逆方向の適切な予旋回を与えれば入口案内羽根がないものと比べて高い圧力係数が得られるとともに，高効率が得られることを示した．

日本機械学会論文集(B編)


順圧力こう配下の再層流化乱流境界層の特性 --- VITA法によるバースト構造の解析

乱流境界層の再層流化に関する実験的研究である．この再層流化は流れを縮小させて順圧力勾配を加えることによって行った．境界層内の平均·変動速度を熱線風速計とI型熱線プローブを用いて測定し，VITA法を用いてバースト構造について考察した．再層流化は乱流境界層の外層部分から発生するという従来の推測が支持される結果を得た．また再層流化するとバーストの発生は減少する．しかしこの周波数をテイラー微小時間で無次元化すると圧力勾配にかかわらず一定になる．再層流化は境界層内層のバーストを特別には弱めないが，イジェクション，スイープには変化を及ぼすことが混合距離を用いた考察から示された．

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


魚類移送用斜流ポンプの開発に関する研究

魚類移送用斜流ポンプの開発に関する研究

魚類移送用ポンプとして新しい考えのもとに開発した厚翼の2枚羽根斜流ポンプの性能特性や羽根車出口の流れを明らかにするとともに，2枚羽根の本羽根車の滑り係数を検討し設計資料を提案した．

日本機械学会論文集(B編)


遠心送風機ケーシング内の流動状態に関する研究 --- 第2報，ケーシング内の流れの可視化

上記48の論文で示された渦巻き室から吐出し管に向かう流れの圧力回復率が高い理由を流れの可視化によって調べた．舌部付近では，渦巻室内に吸い込まれる境界層があり，吐出し管へ向かう流れの境界層は薄くなっていることから，圧力回復率が高い要因は二次流れの遠心力とこの境界層の吸込みであることを示した．

日本機械学会論文集(B編)


遠心送風機ケーシング内の流動状態に関する研究 --- 第1報，ケーシング内の圧力分布および圧力回復率

羽根車外周にディフューザ部を持たず，舌部すきまの大きい遠心送風機ケーシング内の静圧測定を行い，ケーシング内の圧力回復は設計点では，渦巻室内で4割，残りの6割はそこから吐出し管へ向かう短い区間で起きており，この領域が性能の良いディフューザの役目を果たしていることを明らかにした．

日本機械学会論文集(B編)


横流ファンの性能と内部流れに関する研究

横流ファンの性能と内部流れに関する研究

横流ファンのスクロール形状のうち，のど部幅とスクロール広がり形状がファン性能や内部流れに及ぼす影響を検討し，ノド部幅の大きさは羽根車内部に形成される渦の位置やファン性能に大きな影響を及ぼす重要なパラメータであること，渦の移動に伴って吐出し領域が狭められるとファンの圧力係数が増大することなどを明らかにした．

日本機械学会論文集(B編)


Unsteady Fluid Forces on a Blade in a Cross-Flow Turbine

The experimental and theoretical studies for determination on fluid forces on the blade in a cross-flow turbine are conducted. In the experiment, the tangential and radial forces are measured. In the theoretical study, they are calculated numerically using the unsteady momentum theory. The calculated results are compared with experimental data and good agreement between them is demonstrated. Furthermore, the maximum forces are found to occur immediately before the blade leaves the nozzle exit in both the experimental and theoretical results.

クロスフロー水車の羽根にかかる流体力の実験的，理論的研究を行った．実験では，接線方向力，半径方向力を測定した．理論解析では，非定常運動量理論を用いた．計算と実験はよく一致した．さらに最大力は羽根がノズル出口を去る直前に発生することが明らかになった．

JSME International Journal, Series B: Fluids and Thermal Engineering


順圧力こう配下の再層流化乱流境界層の特性

順圧力こう配下の再層流化乱流境界層の特性

乱流境界層の再層流化に関する実験的研究である．この再層流化は流れを縮小させて順圧力勾配を加えることによって行った．境界層内の平均·変動速度を熱線風速計とI型熱線プローブを用いて測定し，速度分布，乱流統計量について考察した．また変動速度の確率密度関数の形状の変化をK-Lダイバージェンスを用いて定量的に説明した．再層流化は乱流境界層の外層部分から発生するという従来の推測が支持される結果を得た．再層流化過程では，乱流領域の境界層内に占める割合が減少し，渦塊は大型化して高周波成分の寄与が減少する．

日本機械学会論文集(B編)


往復流におけるクロスフロー形波力水車の作動特性

往復流におけるクロスフロー形波力水車の作動特性

対称形クロスフロー水車を用いた波力水車について往復流中の水車性能に及ぼす羽根車の慣性モーメントの影響を実験的に明らかにした．さらに本水車の相似則を考慮した運動方程式を導き，定常特性を準定常的に用いたシミュレーションによって慣性モーメントが変化した場合にも往復流中の回転数，効率などの作動特性を評価できることを示した．

日本機械学会論文集(B編)


スモークワイヤ法による空気流の流速測定

スモークワイヤ法による空気流の流速測定

スモークワイヤ法によって低速空気流の流速を測定する方法を提案し，発煙遅れ時間，白煙の浮上速度，発煙線の形成する後流や白煙の加速性等が流速測定精度に及ぼす影響について，吸込み風洞を使用し，種々の発煙条件のもとで主流速度を変化させて調べた．


クロスフロー水車の吸出し管に関する研究

クロスフロー水車の吸出し管に関する研究

クロスフロー水車の吸出し管に関して，ランナ中心から放水面までの落差が比較的大きい場合と小さい場合について，吸出し管の好適形状および吸出し管内水位が水車性能に及ぼす影響について調べたものであり，特にランナが水没した運転状態における水車性能および内部流れについて検討した．

日本機械学会論文集(B編)


多板式層流ファンの羽根車内の流れ解析

多板式層流ファンの羽根車内の流れ解析

多板式層流ファンの羽根車内の流れを子午面内の非粘性解析と平行平板間の粘性解析を組合わせて，準三次元的に解析する方法を示した．本解析法を適用することによって，多板式羽根車内の流れはシュラウド側円板間で小さくなり，羽根車出口の流れは軸方向に非一様な分布を示すことを明らかにした．

日本機械学会論文集(B編)


波力水車の運転特性に関する研究

波力水車の運転特性に関する研究

対称形クロスフロー水車を用いた波力水車について上下往復流中の水車性能に及ぼすケーシング形状の影響を調べるとともに，一方向流中の定常特性を準定常的に用いて本水車の動特性のシミュレーションを行い，回転数，効率などの作動特性を評価できることを示した．

日本機械学会論文集(B編)


クロスフロー水車の羽根に働く流体力

クロスフロー水車の羽根に働く流体力

クロスフロー水車の羽根に働く非定常な流体力をひずみゲージ，スリップリングを用いて実験的に求めるとともに運動量法則を用いて数値解析を行い，計算値は実験とかなり良く一致すること，接線方向力，半径方向力ともに羽根がノズル出口の噴流から脱出するノズル先端近傍で最大値を示すことを明らかにした．

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


テーパ円柱および段付円柱の後流渦

テーパ円柱および段付円柱の後流渦

一様流中にあるテーパ円柱および段付円柱のスパン方向の三次元性が渦流出および後流に及ぼす影響を検討した．テーパ円柱において，スパン方向にセル構造がみられ，セルの境界には流出渦のY字形結合が見られること，段付き円柱では直径比0.64以上では流出渦にY字形結合が見られ，0.56以下では段位置で流出渦は切れていることを示した．

日本機械学会論文集(B編)


平板上の突起より発達する乱流くさびの構造の研究

平板上の突起より発達する乱流くさびの構造の研究

層流境界層の乱流遷移に関する実験的研究である．この遷移は3次元突起列によって強制的に生じさせるものである．層流境界層内に単一の3次元突起が存在すると，その下流にくさび形の乱流領域(乱流くさび)が形成される．この乱流くさび領域の平均·変動速度を熱線風速計とI型熱線プローブを用いて測定し，くさびの輪郭線や広がり角度を明確な定義に基づいて示した．また平均量は突起直後では十分発達しておらず，下流に向かって徐々に発達することが明らかになった．

日本機械学会論文集(B編)


多板式層流ファンに関する研究 --- スクロール広がり角が性能に及ぼす影響

多板式層流ファンに関する研究 --- スクロール広がり角が性能に及ぼす影響

低騒音であることが期待されるが，効率が低い多板式層流ファンの性能向上を目的としてスクロール広がり角の影響を検討した．本ファンは羽根車出口流れ角が極端に小さく，かつ流速が大きいため広がり角が1，2°の小さいスクロールを用いればスクロール流入時の減速損失が減少し，効率は増大するが，最高効率点が小流量側へ移動することを示した．

日本機械学会論文集(B編)


波力発電用クロスフロー水車に関する研究

波力発電用クロスフロー水車に関する研究

波の往復流に対処できるように，羽根車の周りに二つの軸対称ノズルをもつ波力発電用のクロスフロー水車を考案し，その性能と内部流れを取り扱ったものである．この対称形クロスフロー水車が往復流中で自己整流作用を持つこと，羽根車内部に渦が形成されること，往復流の減速時に多くの出力を発生することなどを明らかにした．


A Numerical Method of Flow through a Cross-Flow Runner

本論文は，従来一次元流れとして扱われてきたクロスフロー水車の羽根車内の流れを二次元流れとして解析した．羽根車の相対流れにおける流線に沿う非定常流れを数値解析し，羽根車内を通り抜ける流れの位置が羽根車回転数とともに変化する様子を示すとともに，羽根車の周囲に沿う流れが周方向に一様でないことを明らかにした．


クロスフロー水車性能に及ぼす羽根車とノズルのすきまの影響

クロスフロー水車性能に及ぼす羽根車とノズルのすきまの影響

本論文は，クロスフロー水車の羽根車とノズルとのすきまが，漏れ流量及び水車性能に及ぼす影響について調べたものである．羽根枚数が30枚以上の羽根車では，すきまの大きさはもれ損失だけでなくノズル出口および羽根車内の流動状態に影響を及ぼし，最高の水車効率が得られる最適すきまが存在することを明らかにした．

日本機械学会論文集(B編)


クロスフロー水車発電機システムの動特性

クロスフロー水車発電機システムの動特性

本論文は，クロスフロー水車―直流他励発電機システムのエネルギーの流れより基本方程式を求め，その定常特性の解析法を確立し，実測値と比較することにより，その特性がいかに変化するかを明らかにした．次に負荷トルク変動時の動特性を明らかにするために，各要素のトルク方程式を導出し，実測値と理論値を比較して，伝達関数が妥当であることを確かめた．

日本機械学会論文集(B編)


風車の抵抗翼式制御に関する研究

風車の抵抗翼式制御に関する研究

本論文は，風車の回転数の上昇に対して抵抗翼を開くことによって過大な動力を吸収する抵抗翼式空気ブレーキの設計基礎データを得る目的で，抵抗翼まわりの三次元流れを調べるとともに，吸収動力を見積もるための抵抗翼の抵抗係数の算出式を導いたものである．


管路内に組み込まれたクロスフロー水車に関する研究(流出側ケーシング形状による影響)

本論文は，工場余剰水，下水処理場排水などの配管路に水車を組込み，エネルギーの回収を目指したものであリ，水車性能の上からみた最適ケーシング形状について調べた．

日本機械学会論文集(B編)


潮汐発電用クロスフロー水車に関する研究(第2報 往復流水車における流路断面積変化による影響)

本論文は，第1報に続き往復流に対応できる潮汐発電用水車の高効率化を目指したものであり，約60%にまで効率を上昇させるとともに流路断面積変化は広がり角8度程度が良い事を明らかにした．

日本機械学会論文集(B編)


潮汐発電用クロスフロー水車に関する研究 --- (第1報 同一方向に回転する往復流水車)

日本機械学会論文集(B編)


クロスフロー水車に関する研究(ノズル出口弁による流量·出力制御)

クロスフロー水車に関する研究(ノズル出口弁による流量·出力制御)

本論文は，クロスフロー水車の流量·出力制御法としてノズル出口弧に沿って周方向にスライドし，ノズル開度を調整する出口弁を有するノズルについて，従来のフラップ式ガイドベーンと比較検討を行い，この新しい出口弁付きノズルがガイドベーン付ノズルに比べ幅広い流量範囲にわたり高効率の水車性能が得られ，かつ流動状態が弁開度によらず滑らかであることを示した．

日本機械学会論文集(B編)


クロスフロー水車に関する研究(羽根枚数および羽根出口角の影響)

クロスフロー水車に関する研究(羽根枚数および羽根出口角の影響)

本論文は，クロスフロー水車の性能に影響を及ぼす羽根車形状のうち，特に重要と思われる羽根枚数および羽根出口角について調べたものである．羽根枚数は30枚程度，羽根出口角はβ＝80∼90度が良いことを水車性能および内部の流動状態から示した．羽根枚数とすべり係数との関係についても述べている．

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


ペルトン水車バケット内の流れ解析(第2報)

ペルトン水車バケット内の流れ解析(第2報)

本論文は，第1報に続きバケット面上の流れの厚みを考え，この厚みに基づく圧力を考慮した運動方程式を導きルンゲ·クッタ法を用いてバケット内の流れの数値計算を行い，妥当性あるフローパターンを得た．

日本機械学会論文集(B編)


ペルトン水車バケット内の流れ解析(第1報)

ペルトン水車バケット内の流れ解析(第1報)

本論文は，ペルトン水車バケット内の流れを理論的に知ることができるように，流体粒子について回転座標系に対しての運動方程式を導き，バケット形状や流入状態のデータを与え，コンピュータを使ってシュミレーション計算を行った．

日本機械学会論文集(B編)


A Numerical Method of Free Jet from a Cross-Flow Turbine Nozzle

本論文は，任意曲面形状を持つにノズル内およびノズル出口流れを数値計算する方法を開発し，それらをクロスフロー水車のノズルからの噴流の計算に適用し，得られた結果が実験値と良く一致することを示した．またこの解析によってノズル形状がノズル出口流れに及ぼす影響について明らかにした．


クロスフロー水車のノズルからの噴流に関する研究

クロスフロー水車のノズルからの噴流に関する研究

本論文は，側壁が非対称で曲面形状を持つクロスフロー水車のノズルからの噴流についてシュワルツ·クリストッフェル変換を用い，ノズル内およびノズル出口流れを数値計算し，実験値と良く一致することを示すとともに，この解析によってノズル形状がノズル出口流れに及ぼす影響について明らかにした．

日本機械学会論文集(B編)


多段型ジェットポンプによる高揚程輸送に関する研究

多段型ジェットポンプによる高揚程輸送に関する研究

本論文は，ジェットポンプのノズルより噴出する駆動流体と被駆動流体が混合した後，その混合流体の一部を回収して再び圧力水として用い，ノズルより噴出させる多段型ジェットポンプを開発し，これによる高揚程輸送が可能であることを示した．


吸込みを有するディフューザの性能

吸込みを有するディフューザの性能

本論文は，ディフューザ入口部と拡大部との圧力差を利用してディフューザ壁面からその壁面に発達する境界層または逆流域を吸い込み，その流体をディフューザ入口部の主流に放出させる吸い込み装置を有する二次元及び円錐ディフューザについて実験を行い，吸込位置を剥離点直前に設置すればかなり圧力回復率が向上することを示した．


Analysis of the Flow through Dynamic and Stationary Cascades of Axial Pump by Singularity Method

特異点法を用いて軸流ポンプの動翼と静翼を通過する流れを数値解析する方法を提案するとともにこれを用いて，動静翼内の流動状態を検討した．また，内部流動状態に及ぼす流量および回転数の影響を示した．

Bulletin of Faculty of Engineering, The University of Tokushima


Pressure Recovery in a Centrifugal Blower Casing

スクロール内の検査面に角運動量法則を適用して求めたスクロール巻終わりの流量に対する舌部すきまを通る再循環流量の比率，およびスクロール巻終わりから吐き出し口に向かう区間の圧力回復率の計算値は，吐き出し流量が変化した場合にも実験値と良い一致が得られることを示した．


An Analysis of Flow through a Cross-Flow Runner

本論文は，従来一次元流れとして扱われてきたクロスフロー水車の羽根車内の流れを二次元流れとして解析し，実際のクロスフロー水車の実験値と比較した．解析値と実験値は良い一致を示した．


クロスフロータービンに関する研究 --- 性能に及ぼすノズルの影響

クロスフロータービンに関する研究 --- 性能に及ぼすノズルの影響

本論文は，小水力水車として注目されているクロスフロー水車についてその基本特性を調べるとともに，ノズル開き角度やノズル幅などのノズル形状が水車特性に及ぼす影響について実験的に調べたものである．


ペルトン水車バケット内の流れ解析

ペルトン水車バケット内の流れ解析

本論文は，ペルトン水車バケット内の流れを理論的に知ることができるように，一つの流体粒子について回転座標系に対しての運動方程式を導き，バケット形状データや流入状態のデータを与え，コンピュータを使ってシミュレーション計算を行った．


ターボ機械羽根車内の流れ解析

ターボ機械羽根車内の流れ解析

本論文は，フランシス水車内の部分負荷から過負荷にわたる広範な流れを準三次元解析により求めた．子午面流れは差分法により，翼間流れは特異点法により計算し，それらの流れの間でデータをやり取りしながら逐次解法によりユニークな解を求め，実験値と比較的良く一致することを示した．


スモークワイヤ法による流速測定時に生ずる誤差について

スモークワイヤ法による流速測定時に生ずる誤差について

本論文は，スモークワイヤ法による空気流の測定において発煙遅れ時間，白煙の浮上速度，発煙線の後流や白煙の加速度が測定精度に及ぼす影響を吸込風胴を使用し，種々の発煙条件のもとで主流速度を変化させ調べた．そしてそれぞれの影響を定量的に見積もるとともに実用的な補正式を提案した．


高炉排ガスエネルギー回収タービン内の流動状態およびダスト付着に関する研究

高炉排ガスエネルギー回収タービン内の流動状態およびダスト付着に関する研究

本論文は，高炉排ガス用という特殊なタービンについて，各部の流動状態を測定するとともにダストとして草木灰および石炭粉を使った付着実験を行い，ダスト付着と流動状態との関係を明らかにしたものである．


吸い込みによる2次元ディフューザの性能改善に関する研究

吸い込みによる2次元ディフューザの性能改善に関する研究

本論文は，ディフューザ入口部と拡大部との圧力差を利用してディフューザ壁面からその壁面に発達する境界層または逆流域を吸い込み，その流体をディフューザ入口部の主流に放出させる圧力回復率向上装置を考案試作し，実験を行い，同じ広がり角で同じ面積比の二次元ディフューザの性能をかなり改善できることを示した．


ラジアルタービン内の流れ解析(チョーク流量の推定)

ラジアルタービン内の流れ解析(チョーク流量の推定)

本論文は，高炉排ガスエネルギー回収タービン内の流れを準三次元解析するためのプログラムを開発し，さらに流路に発達する境界層の計算を行い，ブロッケージがチョーク流量に及ぼす影響を考慮した．また，羽根車出口の境界層厚さに基づいて羽根車内の損失を見積もり，この値を用いて羽根車内の損失を基礎式の中で考慮できるようにした．


大気拡散モデル実験に関する研究 --- 第2報 山前方線煙源による山後方の濃度分布について

本論文は，乱流境界層中の山付近の拡散状態を知るとともに，山前方排ガスによる山後方濃度場を知ることを目的として，トレーサとして炭酸ガスを用いて実験し，山付近の濃度場を調べるとともに山後方の剥離渦内濃度の推定法について述べたものである．


ガス圧式動力義肢の開発 --- 第2報 小型軽量化を目的とした試作第2号機の開発

本論文は，前報の試作第一号機を改良し，軽量化を達成するとともに多機能化を実現した義肢の開発について述べたものである．


本論文は，動力源としてガス圧を利用した多機能を実現するための義手の機構の開発について述べたものである．

Bulletin of Faculty of Engineering, The University of Tokushima


大気拡散モデル実験に関する研究 --- (大気境界層中の山近傍の流れ)

大気拡散モデル実験に関する研究 --- (大気境界層中の山近傍の流れ)

本論文は，大気境界層中の山近傍の拡散現象を明らかにする目的で，拡散現象にとって重要な運動学的相似と乱流状態の相似を満足させた風胴モデル実験を行い，山近傍の流動状態及び山後方の乱流状態(乱れ強さ，レイノルズ応力，拡散係数等)について調べたものである．