In this paper, flow behavior and topology structure in a highly loaded compressor cascade with and without plasma aerodynamic actuation (PAA) are investigated. Streamline pattern, total pressure loss coefficient, outlet flow angle and topological analysis are considered to study the effect and mechanism of the plasma flow control on corner separation. Results presented include the boundary layer flow behavior, effects of three types of PAA on separated flows and performance parameters, topology structures and sequences of singular points with and without PAA. Two separation lines, reversed flow and backflow exist on the suction surface. The cross flow on the endwall is an important element for the corner separation. PAA can reduce the underturning and overturning as well as the total pressure loss, leading to an overall increase of flow turning and enhancement of aerodynamic performance. PAA can change the topology structure, sequences of singular points and their corresponding separation lines. TypesⅡ and Ⅲ PAA are much more efficient in controlling corner separation and enhancing aerodynamic performances than type Ⅰ.
With the aim of deepening the understanding of high-speed compressor cascade flow,this paper reports an experimental study on NACA-65 K48 compressor cascade with high subsonic inlet flow.With the increase of passage pressurizing ability, endwall boundary layer behavior is deteriorated, and the transition zone is extended from suction surface to the endwall as the adverse pressure gradient increases.Cross flow from endwall to midspan, mixing of corner boundary layer and the main stream, and reversal flow on the suction surface are caused by corner separation vortex structures.Passage vortex is the main corner separation vortex.During its movement downstream, the size grows bigger while the rotating direction changes, forming a limiting circle.With higher incidence, corner separation is further deteriorated, leading to higher flow loss.Meanwhile, corner separation structure, flow mixing characteristics and flow loss distribution vary a lot with the change of incidence.Compared with low aspect-ratio model, corner separation of high aspect-ratio model moves away from the endwall and is more sufficiently developed downstream the cascade.Results obtained present details of high-speed compressor cascade flow,which is rare in the relating research fields and is beneficial to mechanism analysis, aerodynamic optimization and flow control design.
