Experimental investigation on a high subsonic compressor cascade flow

Abstract

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.

The effect of dimpled surface on loss reduction and vortices in a highly loaded compressor cascade

“…Its main geometrical and aerodynamic parameters are summarized in Table 1. 21 In the simulation of cascade, one blade passage was selected. Periodic boundary conditions were set on both sides of flow passage.…”

Control of Corner Separation with Plasma Actuation in a High-Speed Compressor Cascade

“…The two-equation k-ω eddy viscosity model is used to solve the Reynolds Stress in the RANS equations. According to the experimental study by Zhang et al [24], for the incidences studied in this paper, the corner separation will not develop to the mid-span. Hence, the symmetrical boundary is used at mid-span to reduce the simulation cost.…”

“…The accuracy of this model in simulating the body force of the plasma actuation has been validated by Suzen et al [25] as well as Giorgi et al [21], and, according to the discussion of Cork et al [26], this model could qualitatively simulate the distribution of the body force of the plasma actuation. According to the experimental study by Zhang et al [24], for the incidences studied in this paper, the corner separation will not develop to the mid-span. Hence, the symmetrical boundary is used at mid-span to reduce the simulation cost.…”

“…Its main geometrical and aerodynamic parameters are shown in Table 1. Previously, Zhang et al [24] have investigated the suitable RANS (Reynolds-averaged Navier-Stokes) numerical method to simulate the NACA65-K48 high-speed compressor cascade flow accurately and reliably. Based on their findings, the following numerical method is used in this paper to simulate the high-speed compressor cascade flow, and the comparisons between the experimental and numerical results, which can be found in reference [24], are omitted here.…”

“…The inlet boundary is 1.5 chord lengths upstream of the blade's leading edge, and the outlet boundary is 2.5 chord lengths downstream of the blade's trailing edge. At the inlet, total pressure distributions along the spanwise direction together with a fixed total temperature from experiments (see for example in [24]) are imposed. At the outlet, the average static pressure boundary is applied to guarantee that the inlet Mach number is kept constant at 0.7 at different incidence angles.…”