Influence On Performances Of High-load Rectangular Compressor Cascade With Boundary Layer Suction

Adopting highly loaded compressor cascades is an effective way to improve the pressure ratio of aeroengines,however,due to the characteristic of large turning angle that belong to high-load compressor cascades,the separation of the boundary layer is easily formed under the action of strong adverse pressure gradient in the cascade passage,leading to the stall that arises in the corner,which seriously influences to promote the performance of compressor.Therefore,it is important to explore reasonable flow control methods,at present,as one of the active flow control methods,the boundary layer suction has been proved to be able to effectively delay the flow separation and reduce aerodynamic loss.Under the above mentioned conditions,it is the key to further improve the performance of the compressor by deeply carrying out the mechanism of the internal separation flow in the boundary layer suction control cascade flow field.This paper based on the high-load compressor cascades NACA65-010 as the object,using the numerical simulation and experiment research to explore the boundary suction on the effect of the cascades aerodynamic performance,and mapped the vortex structure of different suction schemes.Firstly,the CFD that was verified by an experiment to study the original cascade numerical simulation,it is founded that there is mainly passage vortex?concentrated shed vortex?corner vortex and trailing shed vortex in the original cascade,the mixing of passage vortex and concentrated shed vortex is the source of high loss area.After using the asymmetric boundary suction near separation point can maximize the weakening or even eliminate flow separation on the suction side,greatly weaken the strength of the concentrated shed vortex,thus significantly reduce the aerodynamic loss on the suction side,but under the asymmetric suction,enlarge the span-wise pressure gradient in passage,the migration of non-suction side on span-wise becomes more intense,thus in non-suction side,there is a phenomenon of separation in advance and loss increases.The scheme of SS is mainly removing the low energy flow that on suction side,the effect of lateral migration from pressure surface to suction surface is not strong,so it isn't delay the separation point,the vortex structure of original also exists in suction surface aspiration schemes,because the generating of concentrated shed vortex was delayed,the high loss in corner was recovered.Due to the increase of flow kinetic energy on suction surface,the characteristic of flow near suction surface was enhanced,and enlarged the turning angel,restrained span-wise migration,the mixing condition at the trailing edge was reduced,so the flow capacity of the mid-span was improved obviously.On variable suction flow,the end-wall asymmetric suction exists an optimal suction flow that on optimal suction position,the continued increase suction flow may reduce the overall aerodynamic performance due to the deterioration of non-suction side.In this paper,the aerodynamic performance of suction surface aspiration is more and more obvious with the increase of suction flow.Next,an experimental study of asymmetric end-wall boundary layer suction was carried out,firstly,the experimental verification of the asymmetric boundary layer suction on design incidence was performed.The outlet total pressure loss coefficient and the end wall static pressure coefficient of the end wall of the suction side were measured respectively.Then the asymmetric end wall suction on various incidences was optimized for the best scheme.The asymmetric suction and comparison between the symmetrical suction and asymmetric were performed.The experimental results and the numerical results showed a good agreement,which further verified the correctness of the numerical simulation.