The activity will focus on compressor air flow which will be analyzed in a dedicated compressor test module. The experimental part will investigate in particular the stalling behavior in a high-speed radial compressor. Detailed measurements of the internal flow will be performed to help understanding the transient behavior of the compressor. The effects of stage matching (variable IGV) on the surge limit will be studied and CFD predictions at off-design conditions will be performed. Please refer to the full topic descriptions document published in this call.