Effect of circumferential non-uniformity of inlet flow on flow and heat transfer in a precooler
The air pre-cooler is capable of reducing the air temperature entering the compressor at a short time,increasing the pressure ratio and the thrust.The circumferential non-uniformity of the pre-cooler inlet flow leads to non-uniformity cooling,which has an important effect on the efficiency of the pre-cooled engine cycle.Referring to the operating parameters of a pre-cooled engine,the physical model of the precooler is properly simplified,and the coupled computational method of two-dimensional flow field and three-dimensional tube bundle unit is proposed,and then a full-scale simulation of the precooler is carried out.The effects of geometric parameters of the precooler flow deflector are discussed,and the optimized parameters of flow deflector are obtained,which reduces the pressure drop by 13.1%.The effects of inlet flow circumferential non-uniformity on the flow field are discussed,and the inlet flow is more distributed to the tube bundle in the 4th region.The flow dead zone formed by the incoming air in the 1st region impedes the flow and increases the inlet angle of the unit tube bundle in the 1st region.The effects of flow uniformity and air inflow angle on heat transfer performance are discussed,and the coupling heat transfer mechanism of the microtube bundle heat exchanger with large temperature difference is revealed.The maximum deviation of the total heat transfer for the precooler is 2.45%,so the impact of air circumferential non-uniformity at the precooler inlet on the heat transfer of precooler can be neglected.
国家科技期刊平台
NSTL
万方数据
维普
