Effect of the spanwise non-uniformity of inflow velocity on the flow field in vaned diffuser

摘要：

　　The numerical investigation is conducted for a centrifugal compressor diffuser with different inflow conditions: the uniform and spanwise non-uniform inflow condition.In this paper,the non-uniform inflow condition means that the Mach number varies along the span in a linear distribution,and it is highest at shroud and lowest at hub,but the static aerodynamic parameters are uniform.It is demonstrated that the diffuser performance is weaker with the non-uniform inflow condition than that with uniform condition.For the case with the non-uniform inflow,the more kinetic energy is converted to the pressure energy at the position of the low Mach number,and the reversed pressure gradient is larger near hub than the same inlet Mach number with uniform inflow..The low speed flow near hub going through large reversed pressure gradient is easier to separate,hence,a separation vortex occurs at the pressure side close to hub,and the flow near hub turns to the vortex and mixes with it.The pressure gradient at the first half of pressure side of vane is largest because of the shape of pressure side,so the separation vortex is generated at middle of pressure side of vane.The normal pressure gradient at S1 surface near hub caused by the separation vortex makes the flow turn to pressure side and enlarges the vortex.

关键词： Diffuser Flow filed analysis Numerical simulation Non-uniform inflow Secondary flow Separation vortex.

作者: Xiaoyu Zhang Jie Chen Guoping Huang

作者单位: Jiangsu Province Key Laboratory of Aerospace Power Systems,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

会议类型: 国际会议

会议名称: The 5th International Symposium on Jet Propulsion and Power Engineering(第五届喷气推进与动力工程国际会议)

会议地点: 北京

会议语种:英文

页码: 1-6

在线出版日期: 2014-09-15（万方平台首次上网日期，不代表论文的发表时间）