Micro Turbojet Engine Test

In recent years, micro gas turbine engine has become a very attractive propulsion system due to its high thrust-weight ratio, low specific fuel consumption, simple structure and low cost, especially meets the propulsion demand of small-sized aircraft, such as unmanned aerial vehicle and cruise missile. In this dissertation, the working process of micro gas turbine engine was analyzed and studied by means of experimental research mainly, theoretical analysis and numerical simulation. The main work reads as follows:(1) A certain centimeter micro gas turbine engine was analyzed theoretically. Based on given initial conditions, overall performance requirements and parts design parameters, pneumatic thermodynamic calculation was conducted. According to design theory and method of inlet, compressor, combustor, turbine and nozzle, some main pre-selected parameters of the engine were selected, and thermodynamic parameters of each feature section were calculated. At last, performance parameters of this engine were calculated.(2) The test stand, fuel supply system and other relevant test systems were established for micro gas turbine engine. With these test equipment, start accelerating characteristics of this engine were studied experimentally, and ignition test, idle test and accelerating test after idle speed were conducted successively. By measuring rotating speed, temperature, thrust and flow rate during the accelerating process, start accelerating performance regularity of micro gas turbine engine were analyzed and summarized. After this, several questions of the engine appeared during experiments were analyzed and solved with corresponding solutions finally.(3) A physical model for annular combustor of the micro gas turbine engine was established, and three-dimensional numerical simulation was conducted to study this combustor under idle state (32000rpm), intermediate stateâ… (72000rpm), intermediate stateâ…¡(90000rpm) and the highest speed state (110000rpm) with CFD software. Then simulation results including speed, temperature and concentration distribution under different working conditions were analyzed. The results reveal that total pressure recovery coefficient of the combustor declines and outlet average temperature rises gradually with ascent of rotating speed, as well as combustion efficiency.