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Influence of blade trailing edge orientation on pressure fluctuation in double-volute of marine pump |
CAO Ruijia1, KONG Xiangxu2*,ZHOU Yisong1,SUN Jinru1 |
1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. China Construction Machinery Co., Ltd., Beijing 100070, China |
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Abstract Fluid pressure fluctuation induced by a rotating impeller when sweeping the tongue of volute is one chief reason for vibration and noise in marine pumps. To reduce the pressure fluctuation, two types of impellers were designed, one with tilted blade trailing edge with respect to the hub surface, one with blade trailing edge perpendicular to the hub surface, and then involved in the identical double-volute of a prototype centrifugal pump. The pressure fluctuations at nine monitoring points within the volute were analyzed in detail by carrying out experiments and numerical simulations. The simulated results indicated that the tilted blade trailing edge could eliminate the pressure fluctuation in the volute at high frequencies but also could reduce the fluctuation amplitude at blade passing frequency further. However, the pressure coefficient at monitoring points b and e, which are located in the fourth cross-sections of the volute, was intensified; additionally, the frequencies for the peak amplitudes were different from those with blade trailing edge perpendicular to the hub surface. Two kinds of blade trailing edge had a similar effect on the pressure fluctuation at the volute outlet. Thus, a tilted blade trailing edge with respect to the hub surface can reduce the pressure fluctuation in the volute due to impeller-tongue interaction effectively.
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Received: 23 April 2018
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