Aerodynamic Investigation of Datum and Slotted Blade Profiles under Different Mach Number Conditions

Abstract

Mach number effects on loss and loading are evaluated in both the datum and slotted compressor profiles under a wide range of incidences based on two-dimensional (2D) computational fluid dynamic (CFD) simulations. First, total pressure loss and loading abilities are compared. Then, three kinds of deficit thickness are defined and evaluated, and a correlation is made between the loading and the momentum deficit thickness at the profile trailing edge. Finally, the nondimensionalized destruction of mean mechanical energy and dissipation function are employed to analyze the loss mechanism. The slotted profile broadens the low loss range towards the positive incidence range. The slotted profile allows a higher diffusion factor (DF) than the datum profile. It is hard to distinguish failure simply based on the DF values, whereas the Zweifel loading coefficient connects well with the low momentum deficit in the profile trailing edge. The peak of the V-shaped distributions in the Ψ - θ d e f plot could better suggest the design condition and determine the correct operating range despite the occurrence of bulk separation. The slotted profile gains the ability of the boundary layer flow near the suction surface to resist the adverse pressure gradient, hence, a reduced shear thickness and a uniformed downstream flow field is obtained.

An unsteady flow control technique based on negative circulation conception and its application to a blade-divergent passage

“…It was found that the unsteady effect produced by the separated vortex had an important influence on the stable operation of the compressor, and it was considered that the study of the separated vortex was very important for predicting the stall of the compressor. Tang et al (2020) proposed a diagram to carry out the blade design by resisting the unfavourable pressure gradient near the suction surface and to determine a correct operating range.…”