微型叶轮机械联合试验台设计

准确的叶轮特性对预估发动机共同工作状态、检验叶轮设计技术、提升发动机性能具有重要意义,但微型涡轮发动机尺寸小,结构紧凑,无法在整机试车中准确测量叶轮性能,故本文针对12 cm直径微发原理样机的离心压气机和向心涡轮设计了联合试验台.该试验台由试验段、控制系统、数据采集系统、测量系统和安全监测系统组成,可实现压气机全转速及涡轮长周期热态试验.试验过程中利用控制系统自动调节压气机与涡轮的功率匹配,实现多转速、多流量的叶轮特性测试.试验台采用模块化设计,可针对直径55～180 mm的叶轮进行试验.为准确测量叶轮效率,本文开发了测量精度达1%的光电扭矩传感器,可实现转速125 000 r/min的高速刚性转轴扭矩测量.

DESIGN OF NEW TEST FACILITY FOR MICRO-TURBO-MACHINERY

Micro-turbine engine has no enough space for measuring impeller characteristics, so the design and the construction of a new test facility of micro-turbo-machinery are presented for micro-centrifugal compressors and radial turbines. The facility is used for the full speed compressor test and the long duration hot turbine test. To rapidly adjust the testing condition, all regulations of the operating state are automatically completed by the control system. The facility is also used for testing the impeller performance with a series of diameter from 55 mm to 180 mm as a result of the modular design. A thermal protection system is designed to avoid the heat distortion caused by the high turbine inlet temperature over 1 100 K and provide a proper experimental environment for the electronic components. A photoelectric torque transducer with the accuracy of 1% is designed to measure the torque of rigid shaft at a high speed of 125 000 r/min. The designing techniques for micro-turbo-machineries are verified by the impeller testing of the facility.