Kinetic Energy Dissipation Caused by the Vortical Structures in Linear Blade Cascade

Abstract

The dissipation of kinetic energy in a linear blade cascade has been extensively studied from both experimental and numerical perspectives. Nevertheless, the impact of vortices on kinetic energy dissipation in the cascade is often assessed under several assumptions that significantly simplify the situation and may underestimate their influence. The presented paper focuses on the kinetic energy dissipation caused by vortical structures. This investigation is based on a new approach to evaluate individual contributions to the overall kinetic energy dissipation in the cascade. Vortices are identified using the H criterion in this paper. A comparison of this new method with the commonly used approach is presented. The experimental research was performed on linear blade cascade with pitch-to-chord ratio t/c = 0.9 for both constant Mach and Reynolds numbers (M2,is =0.4 and Re2,is = 2.5 × 105) and for three different inlet flow angles (α1 = −20°; 5° and 30°).