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

Shigemitsu, Toru,Fukutomi, Junichiro,Kaji, Kensuke,Wada, Takashi Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.1

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Blade-to-blade low velocity regions are suppressed in the case with the splitter blades and total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

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

Shigemitsu, Toru,Fukuda, Hiroaki,Fukutomi, Junichiro Korean Society for Fluid machinery 2016 International journal of fluid machinery and syste Vol.9 No.2

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 Contra-rotating Small-sized Axial Fan at Partial Flow Rate

Shigemitsu, Toru,Fukutomi, Junichiro,Okabe, Yuki,Iuchi, Kazuhiro Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.4

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 contrarotating 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 at a partial flow rate at the inlet and the outlet of each front and rear rotor 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 causes of the performance deterioration of the contra-rotating small-sized axial fan at the partial flow rate is discussed.

Unsteady Flow Condition of Centrifugal Pump for Low Viscous Fluid Food

Shigemitsu, Toru,Fukutomi, Junichiro,Matsubara, Takumi,Sakaguchi, Masahiro Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.4

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

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

Shigemitsu, Toru,Fukutomi, Junichiro,Shimizu, Hiroki Korean Society for Fluid machinery 2012 International journal of fluid machinery and syste Vol.5 No.4

Small-sized axial fans are used as air coolers for electric equipment. 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 the efficiency and the increase of noise. Then, the adoption of contra-rotating rotors for small-sized fans is proposed for the improvement of the performance. In the case of contra-rotating rotors, blade row distance between the front and the rear rotors influences on the performance and the noise. Therefore, it is important to clarify the optimum blade row distance between front and rear rotors. The performance curves of the contra-rotating small-sized axial fan under the condition of different blade row distances are shown and the blade row interaction between the front and the rear rotors are discussed by the numerical results. Furthermore, the optimum blade row distance of the contra-rotating small-sized axial fan is considered.

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

Shigemitsu, Toru,Fukutomi, Junichiro,Toyohara, Masaaki Korean Society for Fluid machinery 2016 International journal of fluid machinery and syste Vol.9 No.2

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 $C_{pmax}=0.17$ in the case with the casing and $C_{pmax}=0.098$ 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 Blade Outlet Angle and Blade Thickness on Performance and Internal Flow Conditions of Mini Centrifugal Pump

Shigemitsu, Toru,Fukutomi, Junichiro,Kaji, Kensuke Korean Society for Fluid machinery 2011 International journal of fluid machinery and syste Vol.4 No.3

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields; automobile radiator pump, ventricular assist pump, cooling pump for electric devices and so on. Further, the needs for mini centrifugal pumps would become larger with the increase of the application of it for electrical machines. It is desirable that the mini centrifugal pump design be as simple as possible as precise manufacturing is required. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, we started research on the mini centrifugal pump for the purpose of development of high performance mini centrifugal pumps with simple structure. Three types of rotors with different outlet angles are prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the outlet angle on performance and internal flow condition of mini centrifugal pumps. In addition to that, the blade thickness is changed because blockage effect in the mini centrifugal pump becomes relatively larger than that of conventional pumps. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-Fluent) to investigate the internal flow condition. It is clarified from the experimental results that head of the mini centrifugal pump increases according to the increase of the blade outlet angle and the decrease of the blade thickness. In the present paper, the performance of the mini centrifugal pump is shown and the internal flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the effects of the blade outlet angle and the blade thickness on the performance are investigated and the internal flow of each type of rotor is clarified by the numerical analysis results.

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

Shigemitsu, Toru,Fukutomi, Junichiro,Agawa, Takuya Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.1

Data centers have been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling small-sized fans; high pressure and large flow rate small-sized fan, are used for servers in the data centers 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 high power cooling fans to meet the demand for high power. There is a limitation of space for servers and geometrical restriction for cooling fans because spokes to support fan motors, electrical power cables and so on should be installed in the cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance to achieve high performance of the cooling fans. In the present paper, the performance and the flow condition of the high power contra-rotating small-sized axial fan with a 40mm square casing are shown by experimental and numerical results. Furthermore, influence of the geometrical shape of the small-sized cooling fan on the internal flow condition is clarified and design guideline to improve the performance is discussed.

Global Deployment of Mitsubishi APWR, a Gen-III+ Solution to the World-Wide Nuclear Renaissance

SHIGEMITSU SUZUKI,YOSHIKI OGATA,YUKIO NISHIHARA,SHIRO FUJITA 한국원자력학회 2009 Nuclear Engineering and Technology Vol.41 No.8

We at Mitsubishi have lined up Gen-III+ solutions for a wide variety of global customers: ATMEA1 of the 1100MWe class ,and an APWR with the largest capacity of 1700MWe. In this paper, we would like to introduce the APWR. With an increased requirement for nuclear power generation as an effective countermeasure against global warming, we have established the APWR plant, a large-capacity Mitsubishi standard reactor combining our accumulated experience and technology as an integrated PWR plant supplier. The APWR plant has achieved high reliability, safety and enhanced economy based on a technology that has been developed with the support of the government and utilities through improvement and standardization programs of light water reactors. Currently, Tsuruga Units 3 and 4, the first two APWRs, are undergoing licensing, while we are making efforts to obtain the standard design certification (DC) of US-APWR and preparing for the European Utility Requirements (EUR) compliance assessment of EU-APWR. Mitsubishi Heavy Industries, Ltd. (MHI) positions the APWR as a core technology that will contribute to the prevention of global warming and meet worldwide requirements.

PI V Measurement of Flow Conditions N ear Casing Tongue of Mini Centrifugal Pump

Toru Shigemitsu,Yusuke Araki 한국유체기계학회 2022 International journal of fluid machinery and syste Vol.15 No.3

Flow conditions near the casing tongue have a s ignificant impact on the performance and stable operation of the centrifugal pump , so the internal flow conditions have been measured by the experiment and PIV measurement. The internal flow conditions of mini centrifugal pumps especially smaller than 100m m are less measured by PIV measurement and its flow conditions near the casing tongue are not clarified yet . Therefore, PIV measurement was conducted near the casing tongue for the mini centrifugal pump having 55mm impeller diameter. The two dimensional op en impeller with the large blade outlet angle  2 =60° was selected as the test impeller. FlowMaster Stereo PIV by LaVision was used for the PIV measurement and the whole test section was made of the acrylic resin including the test impeller. Two CCD camera s with its resolution 2048×2048 pixels were use d and velocity vector and contour were calculated by the PIV measurement software DaVis(Lavision). The internal flow conditions near the casing tongue were focused in this research. The PIV measurement results at different flow rates were shown and the ton gue flow angle was defined to clarify the flow condition near the casing tongue with the impeller rotation. With the increase of the flow rate, the tongue flow angle increases which means the flow near the casing tongue is discharged to the casing throat. In the present paper, the internal flow near the casing tongue is clarified by PIV measurement results and the flow conditions with the impeller rotation are discussed.