APU风车启动中压气机特性计算与分析  

Numerical Analysis of a Centrifugal Compressor in APU Windmill

作　　者：严春晨 朱珈驹 李传鹏[2] YAN Chunchen;ZHU Jiaju;LI Chuanpeng(Test Engineering Department,AECC Aero-engine Control System Institute,Wuxi 214063,China;College of Energy and Power Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,China)

机构地区：[1]中国航发控制系统研究所试验工程部,无锡214063 [2]南京航空航天大学能源与动力学院,南京210016

出　　处：《南京航空航天大学学报》2021年第3期435-441,共7页Journal of Nanjing University of Aeronautics & Astronautics

摘　　要：以某离心压气机为研究对象,数值计算离心压气机风车工作流动特点,分析了工作叶轮叶片受力情况、探讨了APU风车点火转速存在上限值的成因。研究表明,采用等转速特性线插值获得风车状态的流量、压比和温比的精度和置信度是可取的;后弯叶片是冲击气流吹转离心压气机的主要受力面,工作叶轮在5%设计转速(Nd)以下对外输出力矩,辅助涡轮部件提升APU转子转速;转速达15%Nd后,工作叶轮恢复对气流做功,发挥泵气增压功能,气流流量、压力得到提升;出口流量相对值随飞行条件和压气机转速变化规律有助于APU空中点火转速存在上限值的理解。This paper investigates a centrifugal compressor and analyzes a critical phenomenon that an upper limit exists that the restart rotational speed of the auxiliary power unit(APU)cannot surpass.We obtain the numerical features of flows running through the compressor.Based on this,the forces imposed on the rotor blades and the variation trends of the corrected mass flow rate are dissected.These analyses demonstrate that(1)windmill’s state parameters obtained through interpolation in speed characteristic lines,like the mass flow rate,the pressure ratio and the temperature ratio,are accurate and reliable;(2)the main driving area is the backward-curved part of the rotor blades when the incoming flow thrusts the compressor;(3)the rotor outputs torque at a rotational speed of 5%or lower of the designed value,and restores the operation on the flow as the speed rises to 15%or higher of the designed value,resulting in an increase of the mass flow rate and the flow pressure;(4)the trends that the relative mass flow rate follow as the flight condition and the compressor rotational speed change can help to explain the upper limit of the rotational speed during APU airborne ignition.

关 键 词：离心压气机 风车特性 风车起动 数值模拟 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]