Dynamic modelling and analysis of a compressor test rig

Abstract

The compressor is part of a turbomachinery involved in aircraft engine. A modelling of a compressor test rig is operated for a constant speed line and restricted to slow transient time evolution. The test rig is driven thanks to the regulations of the control valves. The time constants of the system are computed to identify the relevant dynamic equations. Assumptions and laws are then gathered in a non-linear system solved by an iterative method finding a convergence point at each time step. The sensibility of the valve opening on the whole system is studied by a perturbation method. It appears that the largest time constant is led by the thermal inertia of the circuit. The dynamic behaviour of the fluid is simulated in both Matlab (code source) and Simulink (graphical environment) and leads to the same results.