Design, manufacturing and test of a new electro hydro mechanical fuel metering and control system for a turbojet engine

The present paper introduces a new electro-hydro mechanical fuel metering and control system for a turbojet engine. The developed metering system uses a new direct drive rotary proportional metering valve, which is coupled to a servomotor. The aim of this new design is to modify and optimize the mission of a constant speed turbojet engine. The main innovations in the present design include: the rotary actuating mechanism, rotary metering valve configuration, direct drive rotary metering valve configuration and the special metering flow geometry. Due to rotary direct drive metering section design, the parts count, manufacturing cost and system weight is decreased with respect to usual methods. Another benefit of the innovated valve is improvement of the control resolution. The fuel metering area in the present developed system consists of a triangular shape on sleeve and a rectangular shape on plunger. Mathematical modeling and system simulations are applied to acquire design parameters for different working conditions. After manufacturing a prototype, rig testing is done. The results of simulations and experimental measurements are compared in the last section of the paper.