Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
This paper describes experimental and computational studies to investigate an Effect of Upstream Bent Pipe on Performance characteristics of a Transonic Centrifugal Compressor. To get compressor performances effected by upstream form, static pressure gages and orifice flow meter were applied to a pipeline including a Transonic Centrifugal Compressor for vehicles. Inlet tube of this compressor is exchangeable between straight and bent which have two kind of curvature, 43mm and 49mm. The experiment was carried out from choke flow rate to nearby surge at 140,000rpm. Computationally, RANS was used to study internal flow in straight and bent in detail. About the simulation of bent pipe, all over Computational grid were 62,820300 in straight and 100,510010 in bend. The following aspects were clarified by the experiment: (a) Total pressure ratio declines in the order of decreasing curvature radius, straight, 49mm and 43mm; (b)the declines are remarkable in high flow rate. In contrast, the gap gets small from peak flow point to choke. The computational results show the following: (c) When inlet pipe is bent, compared with straight pipe, total pressure ratio decreases because of pressure loss caused by a bent part. These result suggests that compressor with bent pipe have a wide surge margin because secondary flow restrains a stall and improves aerodynamics performance.
