ANALYSIS OF TURBOJET-ENGINE CONTROLS FOR AFTERBURNER STARTING

摘要

A simulation procedure is developed for studying the effects of an afterburner start on a controlled turbojet engine. The afterburner start is represented by introducing a step decrease in the effective exhaust-nozzle area, after which the control returns the controlled engine var¬iables to their initial values. The degree and speed with which the control acts are a measure of the effectiveness of the particular control system. Data are presented from an electronic analog computer study using the developed simulation procedure. For each of five systems investigated, it is possible to operate with turbine-discharge temper¬ature overshoots of less than 3 percent of rated temperature, which eliminates the problem of damage to the turbine due to overtemperature in that region following an afterburner start. The steady-state errors of speed and temperature can also be reduced to negligible values in the two proportional control systems investigated.