Model Based Design of Fuel Pump Control

Abstract

This paper presents a co-simulation method to design of speed controller for turbojet fuel pump. Expected fuel pump is used for small turbine engine concept with reducer driven by free turbine. The amount of injected fuel into the combustion chamber is based on the speed of the fuel pump which is controlled by the engine control unit. The final flow of fuel into the combustion chamber is restricted by fuel bypass which constricts the return fuel according to pressure in the nozzles. This back fuel bypass has nonlinear and fixed characteristic determined by its structure. The only way how to control the amount of incoming fuel to the engine is the pump speed control. Effect of the bypass represents a variable component in the fuel pump load and from the view of the speed controller it is a disturbance variable. This paper describes the co-simulation model based on the use of MATLAB/Simulink and MSC Adams environment. This simulation uses interconnection of Simulink controller design and simplified model of the fuel pump dynamics in Adams (without hydraulic modelling).