Design Process of Fuel Management Unit of Jet Engine

摘要

The Fuel Management Unit (FMU) is a complicated hydraulic unit with the primary function of metering fuel supply to an engine in response to demand from the ECU (Electronic engine Control Unit). In contrast with other hydraulic units, the FMU must function under wide range of operating conditions. An FMU which meets both stability and response requirements under all operating conditions is very difficult to design. A new development process is introduced, which uses a bond graph method for detailed nonlinear dynamic simulation of the FMU hydraulic circuit in order to evaluate FMU performance and refine the design if necessary. The results of the bond graph analysis and bench test of the FMU agree very well after tuning several parameters such as friction coefficients. Future accuracy improvement of the bond graph analysis will result in significant reduction of hardware bench tests for performance evaluation, and so lower development cost and time.