Modelling and Evaluation of Jet Engine Fuel System Designs

Abstract

This master thesis investigates the main fuel pump of the RM12 engine used in the JAS 39 Gripen C/D fighter jet, with the aim of identifying and modelling the main fuel pump as well as alternative fuel system configurations. The purpose of this project is to understand performance, efficiency, and limitations of the current fuel system, as well as to explore potential improvements using alternative fuel systems and pump architectures. By combining publicly available data, data from uninstalled accessory rig tests, as well as data from uninstalled engine tests, the system model compares the performance of different fuel systems at different steady state operating conditions. The system model predicts pump power usage and fuel heat sink capability among other parameters. These performance parameters have a direct impact on aircraft performance and provide insight in design and optimization of future jet engine fuel systems. The results indicates that a variable displacement main fuel pump or an electrically driven variable speed main fuel pump may be well suited with regards to minimizing power extraction and added heat to the fuel. Further studies of these configurations may therefore be of interest.