关键词: APU进气系统;多孔板;开孔率;数值模拟;气动性能 

Abstract: In order to provide a reference for the design of the Auxiliary Power Units (APU) air inlet system, the aerodynamic performance of a typical dual compressor configuration APU air inlet system with perforated protecting plates was studied using 3D CFD. The operating mode of the basic model with orifice ratio 0.479was investigated under the fixed proportion condition as well as the total mass flow condition. The results show that the outlet total pressure loss consists of several factors, such as throttle and mixing loss near the perforated plates, collision loss near the throat section,turning and boundary layer loss in the duct. The total pressure distribution is mainly affected by duct curvature in radial direction and by the imperforate area of the whole perforated plates in the circumferential direction. Meanwhile, the aerodynamic performances of the APU air inlet system with different orifice ratios were investigated as well. The results show that with the increase of orifice ratio, the total pressure recovery coefficient of the outlet increases accordingly. The APU air inlet system loss and the distortion of load section were mainly affected by perforated plates in small orifice ratio, but by duct curvature in large orifice ratio. The recommended orifice ratio is 0.4~0.6.

Key words: APU air inlet system; Perforated plates; Orifice ratio; Numerical simulation; Aerodynamic performance