Transient aeroengine testing at Stuttgart altitude test facility

摘要

In the Stuttgart ATF, comprehensive transient test programs were carried out recently on full turbofan engines and on turbofan core engines. Whereas full engine testing requires fast facility mass flow variations corresponding to those of the engine, core testing with simulation of the LP components additionally requires the flows to fill or empty the facility intake plenum according to the pressure and temperature variations. Automatic facility control is applied using signals directly from the test object on the transient in progress. Additionally, numerous facility parameters are measured to allow a facility simulation and the calculation of appropriate control valve movements. Testing experience shows a fairly accurate pressure setting, especially for the fast variations during core transients. Due to delay times and heat transfer in the facility intake ducts the fast temperature variations required for core transients are problematic. Transient testing causes high requirements on control valve velocity and accuracy. For further improvement, new valves especially designed for this task will be installed.