泵的應用大部分在於工業界中之傳送流體，近幾年來，許多的研究將以往的水泵小型化以應用於人工心臟上；因此本研究的目的是應用數值分析來模擬其相關流場，並將結果提供流場可視化外，依據分析判斷泵設計之優劣，同時預測小型泵之效率及穩定性，找出最適宜之葉輪葉片出口角度。本研究採用文獻所建議之渦卷殼和葉輪設計方法，並以一圓弧法建構葉片圓弧外形，設計出預期流量為5 l/min、揚程為600 mm、葉輪外徑為50 mm、七片葉片的水泵。渦卷外殼半徑36.3 mm，以供人工心臟之用。接著以數值方式分析不同葉片出口角度之泵，分析結果顯示葉片出口角為30度時，可得最大流量為4.079 l/min，而葉片出口角度為22.5度時其葉輪壓力分佈最為均勻，對於水泵的震動影響最小。另外，由於上述的分析結果都未達設計目標，因此針對最大流量之葉輪（β2＝30∘）以去除輪毂的方式（即增加入口截面積）變更設計，結果發現其最大流量增加69.5％左右、泵出口壓力增加2.5倍左右，其結果已符合當初設計的需求，同時證明入口面積對於泵性能的影響甚大。

Pump is widely used to the fluid transportation in the industry. Recently, the small centrifugal pump has drawn increasing attention on its application in the design of artificial heart. There is a substantial need to realize the flow patterns and shear-stress distribution generated by the pump for a safe application on human body. Therefore, this work aims at the application of the numerical code to simulate the associated flow field inside a small BI centrifugal pump. The numerical outcomes are utilized for the flow visualization to identify the possibility of performance enhancement. The designs of impeller and spiral housing adopted the design scheme that was recommended in the previous literatures. Consequently, a water pump comprised a 72.6-mm-diameter scroll housing and an impeller with 50-mm-diameter and seven airfoil blades is designed to meet the 5 l/min volume-flow-rate requirement for the artificial heart. Then, the efficiencies of pump with different blade outlet angles are analyzed numerically. The analysis shows that the max flowrate will be 4.08 l/min when the blade outlet angle is set at 30 . For the case of 22.5 blade outlet angle, the pressure around the rotor distributes uniformly and thus generates the tiniest vibrations on the pump. However, the results from the above analyses did not approach our previous design goal. Hence, this research intends to remove the rotor hub in order to enlarge the inlet area for producing extra mass flowrate. Numerical simulation indicates that the max flow rate increases about 69.5% while the pump’s output pressure enhances dramatically. In conclusion, this numerical result is not only matching the original design target but also proving that the inlet area affects the pump efficiency and performance substantially.

[1] 神宮 敬, “泵之設計製圖”, 台隆書店出版, 1982.
[2] 蘇宗寶, “離心式泵”, 徐氏基金會出版, 1986.
[3] STAR-CD, Version 3.15, Methodology, 2001.
[4] Sorensen, E., “Potential Flow through Centrifugal Pumps and Turbines”, NACA TM-973, 1941.
[5] Acosta, A.J., “An Experimental and Theoretical Investigation of Two-Dimensional Centrifugal Pump Impeller”, Trans. ASME, Vol. 76, pp. 749-763, 1954.
[6] Bowerman, R. and Acosta, A., “Effect of the Volume on Performance of Centrifugal Pump Impeller”, Trans. ASME, Vol. 79, pp. 1057-1069, 1957.
[7] Murata, S., “Research on the Flow in a Centrifugal Pump Impeller”, Bulletin of JSME, Vol. 5, pp. 95-101, 1962.
[8] Eck, B., “Fans”, Pergamon Press, N.Y., 1975.
[9] Raj, D., “Identification of Noise Sources in Forward-Curved Centrifugal Fan Rotors”, Tennessee Technological University, Ph.D. Thesis, Cookeville, Tennessee, 1978.
[10] Eckardt, D., “Instantaneous Measurements in the Jet-Wake Discharge Flow of a Centrifugal Compressor Impeller”, ASME Journal of Engineering for Power, Vol. 97, pp. 337-346, 1975.
[11] Johnson, M. W. and Moore, J., “The Influence of Flow Rate on the Wake in a Centrifugal Impeller”, ASME Journal of Engineering for Power, Vol. 105, pp. 33-39, 1983.
[12] Inoue, M. and Cumpsty, N. A., “Experimental Study of Centrifugal Impeller Discharge Flow in Vaneless and Vaned Diffusers”, ASME Journal of Engineering for Gas Turbine and Power, Vol. 106, pp. 455-467, 1984.
[13] Thanapandi, P. and Prasad, R., “Centrifugal Pump Transient Characteristics and Analysis Using the Method of Characteristics”, Pergamon Elsevier Science Ltd, pp. 77-89, 1994.
[14] Jude, L. and Homentcovschi, D., “Numerical Analysis of the Inviscid Incompressible Flow in Two-Dimensional Radial-Flow Pump Impellers”, ELSEVIER, Engineering Analysis with Boundary Elements, Vol. 22, pp. 271-279, 1998.
[15] Li, Wen-Guang, “Effects of Viscosity of Fluid on Centrifugal Pump Performance and Flow Pattern in the Impeller”, ELSEVIER, International J. of Heat and Fluid Flow, Vol. 21, pp. 207-212, 1999.
[16] Kelder, J. D. H., Dijkers, R. J. H., Esch, B. P. M., Kruyt, N. P., “Experimental and Theoretical Study of the Flow in the Volute of a Low Specific-Speed Pump”, ELSEVIER, Fluid Dynamics Research , Vol. 28, pp. 267-280, 2000.
[17] Yu, S. C. M., Ng, B. T. H., Chan, W. K., and Chua, L. P., “The Flow Patterns within the Impeller Passages of a Centrifugal Blood Pump Model”, ELSEVIER, Medical Engineering and Physics, Vol. 22, pp. 381-393, 2000.
[18] Kaya, Durmus, “Experimental Study on Regaining the Tangential Velocity Energy of Axial Flow Pump”, PERGAMON Energy Conversion and Management, Vol. 44, pp. 1817-1829, 2002.

[19] Choi, Jong-Soo, McLaughlin, Dennis K., and Thompson, Donald E. “Experiments on the Unsteady Flow Field and Noise Generation in a Centrifugal Pump Impeller”, ACADEMIC PRESS, Journal of Sound and Vibration ,Vol. 263, pp. 493-514, 2002.
[20] Langthjem, M. A. and Olhoff, N., “A Numerical Study of Flow-Induced Noise in a Two-Dimensional Centrifugal Pump. Part I. Hydrodynamics”, ELSEVIER, Journal of Fluids and Structures, Vol. 19, pp. 349-368, 2004.
[21] Langthjem, M. A. and Olhoff, N., “A Numerical Study of Flow-Induced Noise in a Two-Dimensional Centrifugal Pump. Part II. Hydroacoustics”, ELSEVIER Journal of Fluids and Structures, Vol. 19, pp. 369-386, 2004.
[22] Patankar, S. V. and Spalding, D. B., “A Calculation Procedure for Heat Mass and Momentum Transfer in Three-Dimensional Parabolic Flows”, International Journal of Heat Mass Transfer, Vol. 15, pp. 1787-1806, 1972.
[23] 陳柏舟,“ 扇框開孔對軸流風扇流場之數值模擬與實驗研究”, 國立台灣科技大學碩士學位論文, 2004.
[24] 吳兌倩,“ 流線型鰭片散熱座數值與實驗之整合研究”, 國立台灣科技大學碩士學位論文, 2004.
[25] 孫鈞瑋,“ 前傾式離心風機數值與實驗之整合研究”, 國立台灣科技大學碩士學位論文, 2004.