In this final thesis two simulation models have been integrated. The simulation models are models of JAS 39 Gripen?s fuel system, software and hardware. The time consuming and costly work to develop software has made the department of fuel system to build two models in Xmath/Systembuild. The software model also simplifies the comprehension of how the software in the control computer of the fuel system works.

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero.