• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.55-60
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• 2016

We present an experimental setup for measuring the mechanical performance of centrifugal blood pumps. Using a 3D printer to construct supporting parts and magnetic couplings, we developed the measurement setup that can be used for various types of blood pumps. The experimental setup is equipped with sensors to measure a variety of mechanical characteristics of blood pumps including pressure, flow rate, torque, temperature, and rotating speed. Our experimental measurements for two commercial blood pumps are consistent with data provided by manufacturers, which indicates that the our setup offers the accurate measurements of blood pump performance. Utilizing the experimental setup, we tested aqueous glycerin solutions mimicking the density and viscosity of blood, which enabled us to predict the difference in operations using water and blood.

• International Journal of Fluid Machinery and Systems
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• v.8 no.1
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• pp.1-12
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• 2015

In cardiopulmonary support systems with a membrane oxygenation such as a percutaneous cardiopulmonary support (PCPS) or an extracorporeal membrane oxygenation (ECMO), blood pumps need to generate the pressure rise of approximately 200mmHg or higher, due to the high hydraulic resistances of the membrane oxygenation and of the cannula tubing. In order to realize the blood pump with higher pressure rise, higher anti-hemolysis and thrombosis performances, the development of novel centrifugal blood pump composed of two-stage has been conducted by the authors. In the present paper, effective attempts to decrease the wall shear stress and to suppress the stagnation are introduced for the prevention of hemolysis and thrombosis in blood pumps. The hemolysis test was also carried out and it was clarified that the decrease of wall shear stress is effective as a guideline of design of blood pumps for improving the anti-hemolysis performance.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.36-44
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• 2000

The flow at the impeller exit is important to validate engineering design and numerical analysis of pumps. We installed axisymmetric collector instead of the volute casing, so there is no interaction between the impeller and casing. A hot-film probe and a high response pressure transducer are used to investigate the flow at impeller exit and vaneless diffuser region for design and off design flow rate. For a single suction centrifugal pump of low specific speed, the flow field such as velocity, flow angle, and total pressure are measured by traversing the probe across the vaneless diffuser. These data can be used for performance prediction, design, and numerical analysis of pumps.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.574-579
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• 2000

In this study. an off-design performance prediction program for centrifugal pumps is developed. To estimate the losses in an impeller flow passage, two-zone model and two-element in series(TEIS) model are used. At impeller exit. the mixing process occurs with an increase in entropy. In two-zone model. there are both primary zone and secondary zone for an isentropic core flow and an average of all non-isentropic streamtubes respectively. The level of the core flow diffusion in an impeller was calculated by using TEIS model. While internal losses in an impeller an automatically estimated by using the above models, some empirical correlations far estimating external losses. far example, disk friction loss, recirculation loss and leakage loss are used. In order to analyze the vaneless diffuser flow. the momentum equations for the radial and tangential directions are used and solved together with continuity and energy equations.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.234-241
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• 1999

The flow at the impeller exit is important to validate engineering design and numerical analysis of pumps. However, it is not easy to measure the flow at the impeller exit and evaluate the impeller performance since there is usually strong interaction between the impeller and the volute casing. We installed axisymmetric collector instead of the volute casing, so there is no interaction between the impeller and casing. A 3-hole Cobra probe is used to investigate the flow at impeller exit and vaneless diffuser region for design and on design flow rate. For a single suction centrifugal pump of low specific speed, the flow field such as velocity, flow angle, and total pressure are measured by traversing the probe across the vaneless diffuser. These data can be used for performance prediction, desist and numerical analysis of pumps.

• International Journal of Fluid Machinery and Systems
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• v.9 no.2
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• pp.107-118
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• 2016

This paper focuses on the single stage and multistage performance characteristics of centrifugal mixed flow submersible borewell pump. This study reveals that the performance of single stage pump is higher than that of multistage pumps. The head, input power and efficiency of single stage pump are higher than the per stage head, per stage input power and efficiency of multistage pumps. This study is divided into three parts. In the first part, five prototype pumps were made in single stage and multistage construction and the performance tests were conducted. In the second part, numerical validation has been done for different turbulence models and grid sizes. k-Omega SST model has been selected for the performance simulation and was validated with the performance of the test pump with static pressure tappings. In the third part, single and three stage pump performance were simulated numerically and compared with experimental results. The detailed analysis of pressure and velocity distributions reveals the difference in performance of single and three stage pump, due to non-uniform flow and difference in averaged flow velocities at the subsequent impeller inlets except the 1st stage impeller inlet.

• International Journal of Fluid Machinery and Systems
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• v.4 no.4
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• pp.387-395
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• 2011

Single-blade centrifugal pumps are widely used as sewage pumps. However, the impeller of a single-blade pump is subjected to strong radial thrust during pump operation because of the geometrical axial asymmetry of the impeller. Therefore, to improve pump reliability, it is necessary to quantitatively understand radial thrust and elucidate the behavior and mechanism of thrust generating. This study investigates the radial thrust acting up on a single-blade centrifugal impeller by conducting experiments and CFD analysis. The results show that the fluctuating component of radial thrust increases as the flow rate deviates from the design flow rate to low or high value. Radial thrust was modeled by a combination of three components, inertia, momentum, and pressure by applying an unsteady conservation of momentum to the impeller. The sum of these components agrees with the radial thrust calculated by integrating the pressure and the shearing stress on the impeller surface. The behavior of each component was shown, and the effects of each component on radial thrust were clarified. The pressure component has the greatest effect on the time-averaged value and the fluctuating component of radial thrust. The time-averaged value of the inertia component is nearly 0, irrespective of the change in the flow rate. However, its fluctuating component has a magnitude nearly comparable with the pressure component at a low flow rate and slightly decreased with the increase in flow rate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.101-108
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• 2022

Centrifugal pumps are typically used in many slurry industries to transport solid materials. Solid particles in the slurry frequently shock the walls inside the pump, significantly abrading the flow path. Wear damage causes replacement of the pump components, which wastes manpower and time. Therefore, previous studies have been conducted on factors to improve efficiency and life time. This study identifies trends in pumps supplying lime to desulfurized devices from thermal power plants. The shear stress transport(SST) model is used to determine the erosion trend of the centrifugal pump that transfers lime slurry. The purpose of this study is to identify efficiency and erosion trends by selecting three of the various impeller design elements. The three impeller blade design variables mentioned above represent the inlet draft angle and blade angle of leading edge(L.E) and trailing edge(T.E). The maximum value of the erosion density rate tends to be similar to the Input power.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.35-40
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• 2015

Centrifugal pumps consume considerable amounts of energy in various industrial applications. Therefore, improving the efficiency of pumps machine is a crucial challenge in industrial world. This paper presents numerical investigation of flow characteristics in volutes of centrifugal pumps in order to compare the energy consumption. A wide range of volumetric flow rate has been investigated for each case. The standard k-${\varepsilon}$ is adopted as the turbulence model. The impeller rotation is simulated employing the Multi Reference Frames(MRF) method. First, two different conventional design methods, i.e., the constant angular momentum(CAM) and the constant mean velocity (CMV) are studied and compared to a baseline volute model. The CAM volute profile is a logarithmic spiral. The CMV volute profile shape is an Archimedes spiral curve. The modified volute models show lower head value than baseline volute model, but in case of efficiency graph, CAM curve has higher values than others. Finally for this part, CAM curve is selected to be used in the simulation of different cross-section shape. Two different types of cross-section are generated. One is a simple rectangular shape, and the other one is fan shape. In terms of different cross-section shape, simple rectangular geometry generated higher head and efficiency. Overall, simulation results showed that the volute designed using constant angular momentum(CAM) method has higher characteristic performances than one by CMV volute.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.543-545
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• 2004