蜗壳截面尺寸对气动性能影响研究

针对压缩空气储能系统中某闭式向心涡轮,设计不同截面尺寸的矩形截面有叶蜗壳,采用CFD(computational fluiddynamies)方法对带蜗壳的向心涡轮进行整级全周数值计算,研究蜗壳截面尺寸对向心涡轮性能的影响.结果表明,当蜗壳无量纲气动尺寸S1小于0.2时,随着S1的增加向心涡轮性能得到提高并且性能提高的速率逐渐减小;当S1大于0.2后,随着S1的增大向心涡轮的性能保持不变或者略有下降;与所研究用向心涡轮相匹配的蜗壳最优无量纲气动尺寸接近0.2,而蜗壳截面宽度B的变化对向心涡轮性能没有明显影响.通过对向心涡轮压力损失及内部流场的详细对比分析,揭示了S1及B对向心涡轮影响的机理,为向心涡轮的设计和优化提供一定的参考.

Study on the effect of Variation of the Volute cross-sectional dimension on radial turbine performance

This paper designed some rectangular cross-section volutes for a radial inflow turbine used in MW-class compressed air energy storage system. Those volutes have different cross-sectional dimensions. Then, a commercial computational fluid dyanmics (CFD) software was used to simulate the flow and losses within the radial turbine to study the effect of Variation of the Volute cross-sectional dimension on radial turbine. The results of the simlation show that the total to total isentropyefficiency of the radial turbine increases with the non-dimensional volute aerodynamic size S₁ when S₁ is less than 0.2. while the total to total isentropy efficiency of the radial turbine for increasing S₁ is almost constant when S₁ is great than 0.2. The radial turbine with a volute whose S₁ is approximately equal to 0.2 has the maximum efficiency. The width of the volute"s cross-section have no effect on radial turbine"s performance. The mechanism of the effect of volute cross-sectional dimension on the radial turbine performance and losses is revealed by analyzing the flow field and the losses in the radial turbine. in order to provide some reference for further development of radial turbine.