Andrzej S. WITKOWSKI is Professor of Mechanical Engineering at the Silesian Technical University of Technology in Gliwice, where he received his doctor and habilitated doctor degrees. He has more than 50 years of teaching, research, and consulting experience in compressors and fans, wind turbines, aerodynamics, experimental and fluid dynamics. Most of his research is focused on detailed understanding and modelling of the flow field in turbomachines. The specific areas include the rotor wake steady and unsteady flow field in a single-stage compressor, the rotor-stator interaction, and the rotor stall inception in the axial flow low-speed compressor stage. His experience covers a wide spectrum including experimental work, analytical and computational modelling, and improvement in compressor performance through loss correlations. He developed and equipped the axial flow compressor stage laboratory at the Technical University in Gliwice, which now comprises an axial flow low-speed compressor stage. This makes it possible to measure the unsteady flow field in the rotor blade-to-blade channels with the use of three different anemometer systems. He has been involved lately in the analysis of compression and transportation processes for post-combustion CO2 capture applications for pulverized coal-fired power plants. He has received numerous awards granted by the Polish Ministry of National Education. This work is supported by the Polish National Centre of Research and Development in the framework of the Contract: Strategic Research Programme (Advanced Technologies for Energy Generation).