Unsteady Computational Fluid Dynamics Investigation on Inlet Distortion in a Centrifugal Compressor
Unsteady Computational Fluid Dynamics Investigation on Inlet Distortion in a Centrifugal Compressor
复制标题
DOI：
10.1115/1.3147104
复制
发表时间：
2010-07
影响因子：
1.7
通讯作者：
A. Zemp;A. Kammerer;R. Abhari
中科院分区：
文献类型：
--
作者：
A. Zemp;A. Kammerer;R. Abhari
叶片在振动过程中的失效常常是由过度的共振响应引起的。叶片的强迫响应源于非定常流体结构相互作用，如在进口段中由管道弯头、支柱或进口导叶调节。本文介绍了离心式压气机叶片强迫响应研究工作的计算部分。非定常流动模拟用于量化由于入口流动畸变而作用在压气机叶片上的强迫函数。计算中采用实测的进口流量分布作为进口边界条件。非定常研究提供了通过压气机的畸变流的时间演变。时间分辨的叶片压力分布显示了由进气畸变引起的叶片表面动载荷的时间演变。结果表明，强迫函数是最敏感的前缘区，由于进口角的变化。在叶轮稳定线附近，冲角的增加引起了主叶片吸力面的分离，从而显著地改变了非定常的振幅和相位角。对理想化入口流量分布对强制函数的影响的研究表明，与实际入口流量分布相比，峰值幅度增加约30%。
Blade failure in turbomachinery is frequently caused by an excessive resonant response. Forced response of the blades originates from unsteady fluid structure interactions as conditioned in the inlet section by duct bends, struts, or inlet guide vanes. This paper presents the computational part of a research effort that focuses on the blade forced response in a centrifugal compressor. Unsteady fluid flow simulations are used to quantify the forcing function acting on the compressor blades due to inlet flow distortion. The measured inlet flow distribution is applied as inlet boundary conditions in the computation. The unsteady investigation provided the temporal evolution of the distorted flow through the compressor. The time-resolved blade pressure distribution showed the temporal evolution of the dynamic load on the blade surface caused by the inlet distortion. The results suggest that the forcing function is most sensitive in the leading edge region due to inlet angle variations. Toward the impeller stability line the increase in incidence caused separation on the suction side of the main blade and therefore considerably altered the amplitude and the phase angle of the unsteadiness. The investigation of the effect of idealizing the inlet flow distribution on the forcing function showed an increase in the peak amplitude of approximately 30% compared with the actual inlet flow distribution.