The influence of inlet flow distortion on the performance of a centrifugal compressor and the development of an improved inlet using numerical simulations
The influence of inlet flow distortion on the performance of a centrifugal compressor and the development of an improved inlet using numerical simulations
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DOI：
10.1243/0957650011538550
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发表时间：
2001-01
期刊：
影响因子：
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通讯作者：
Yunbae Kim;A. Engeda;R. Aungier;Gregory L. Direnzi
中科院分区：
文献类型：
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作者：
Yunbae Kim;A. Engeda;R. Aungier;Gregory L. Direnzi
摘要 由于入口结构和入口流动结构的不令人满意，入口流动畸变会严重影响离心式压缩机的性能。进行了实验测试，比较了两种不同入口配置的离心压缩机级效率，其中一种是具有恒定横截面积的直管，另一种是具有喷嘴形状的90°弯管。比较测试结果表明两种不同入口配置之间的压缩机级性能存在显着差异，并且讨论了细节以了解暴露于来自弯曲入口配置的扭曲流的压缩机的性能行为。实验研究激发了对新入口设计的需求，并通过数值模拟清晰地了解现有入口设计中的详细流场。本文报告了两种设计方法，其中一种是叶片的位置，另一种是曲率半径的长度。为了更有效的设计方法，建立了叶片最佳位置和数量的通用公式，使得每个带有叶片的分隔流道在径向上具有相同的压力梯度。基于每个设计的管道出口横截面积处的流动特性的比较，从质量平均参数和流动结构方面提出并讨论了数值模拟结果。最后，提出了不同入口系统的新设计，以减少二次流量并为压缩机提供尽可能均匀的流量。
Abstract The performance of centrifugal compressors can be seriously affected by inlet flow distortions due to the unsatisfactory nature of the inlet configuration and the resulting inlet flow structure. Experimental tests have been carried out for the comparison of centrifugal compressor stage efficiency with two different inlet configurations, one of which is straight with constant cross-sectional area and the other a 90° curved pipe with nozzle shape. The comparative test results indicated significant compressor stage performance difference between the two different inlet configurations and the details are discussed to understand the performance behaviour of the compressor exposed to the distorted flow from the bend inlet configuration. The experimental investigation motivated the need for a new inlet design as well as a clear picture of the detailed flow field in the existing inlet design using numerical simulations. Two design approaches are reported in this paper, one of which is the location of vanes and the other the length of the curvature radius. For a more effective design method, a generalized formula is developed for the optimum position and number of vanes in such a way that each divided flow passage with vanes shares the same pressure gradient in radial direction. Numerical simulation results are presented and discussed in terms of mass-averaged parameters and flow structures, based on the comparison of flow properties at the pipe exit cross-sectional area of each design. Finally, new designs of different inlet systems are proposed to reduce the secondary flow and to provide flow as uniform as possible for a compressor.