轴向间距改变对压气机clocking效应影响的数值模拟

采用一种新型的环面叶栅计算方法对两级低速压气机中径处的非定常流动情况进行了数值模拟,针对第二排静叶在一个栅距内的8个不同的时序位置下,同时移动动叶在轴向相对位置,通过数值计算结果表明:在两级静叶间轴向间距不变的情况下,动叶的轴向位置对上游静叶尾迹输运过程有显著影响,在三个CASE计算中,动叶后移时,压气机效率整体最高.轴向间距的缩短对提高整机效率有益.此外环面叶栅计算结果跟平面叶栅结果总体上趋于一致,最高、最低时序位置也相同,但流场信息更为丰富合理;相对于通常的单流道计算,环面叶栅方法更能全面反映全流道周向流动情况,从而为叶轮机械设计及前后叶排间相互干涉研究提供理论依据.

Numerical Simulation of the Influence of Changeable Axial Gap on Compressor Clocking Effect

The unsteady flow at the mid span of a two-stage low speed axial compressor was studied by means of numerical simulation based on a new calculation method of round vane cascade. The calculations were carried out at eight typical clocking positions of stationary blades in the secondary row within one cascade, and meanwhile moving the axial relative positions of dynamic blades. It is found from the numerical simulation results that the axial positions of dynamic blades had significantly influenced the upstream stationary blade wake transport process under the condition of constant axial gap between double stage stationary blades. Among the three CASE calculations, the overall efficiency of compressor is highest when dynamic blades backward. Shortening axial gap is helpful for improving overall efficiency. In addition, the calculation results of round vane cascade are consistent with planar cascade, and the clocking positions with highest and lowest are also the same. field information is However, the flow more rich and reasonable. Compared to the conventional single channel calculation, the round vane cascade method can more fully reflect the circumferential flow situation of whole flow passage. It will provide theoretical basis for the research of impeller machinery design and mutual interference between blades rows.