About Subsonic Compressor Tandem Aerodynamics - A Fundamental Study

Kurzfassung

This paper deals with the description of the fundamental operation principles of a modern high e�cient subsonic compressor tandem cascade. Design recommendations are developed by considering these principles and based on an optimization database with more than 1900 tandem geometries. Therefore, one essential part of the investigation presented is the definition of a highly loaded outlet guide vane application and the design of subsonic tandem cascades by means of an advanced optimization procedure. As boundary conditions for the optimization an inlet Mach number of 0.5 as well as three operating points are defined in order to ensure a maximum working range of 15 deg. Furthermore, three objective functions are used, which are focused on the minimization of the losses at the three operating points and the enhancement of the cascade performance in terms of pressure rise. Afterwards, the optimization database was analyzed in detail with respect to the correlation between the aerodynamic performance parameters and the geometrical parameters of the subsonic tandem cascade. This analysis shows, that there is only a small range of optimal subsonic tandem geometries for a wide range of performance requirements.