To overcome the limitations posed by three-dimensional corner separation,this paper proposes a novel flow control technology known as passive End-Wall(EW)self-adaptive jet.Two single EW slotted schemes(EWS1 and EWS2),...To overcome the limitations posed by three-dimensional corner separation,this paper proposes a novel flow control technology known as passive End-Wall(EW)self-adaptive jet.Two single EW slotted schemes(EWS1 and EWS2),alongside a combined(COM)scheme featuring double EW slots,were investigated.The results reveal that the EW slot,driven by pressure differentials between the pressure and suction sides,can generate an adaptive jet with escalating velocity as the operational load increases.This high-speed jet effectively re-excites the local low-energy fluid,thereby mitigating the corner separation.Notably,the EWS1 slot,positioned near the blade leading edge,exhibits relatively low jet velocities at negative incidence angles,causing jet separation and exacerbating the corner separation.Besides,the EWS2 slot is close to the blade trailing edge,resulting in massive low-energy fluid accumulating and separating before the slot outlet at positive incidence angles.In contrast,the COM scheme emerges as the most effective solution for comprehensive corner separation control.It can significantly reduce the total pressure loss and improve the static pressure coefficient for the ORI blade at 0°-4° incidence angles,while causing minimal negative impact on the aerodynamic performance at negative incidence angles.Therefore,the corner stall is delayed,and the available incidence angle range is broadened from -10°--2°to -10°-4°.This holds substantial promise for advancing the aerodynamic performance,operational stability,and load capacity of future highly loaded compressors.展开更多
As an effective method to influence end wall flow field,non-axisymmetric profiled end wall can improve the aerodynamic performance of compressor cascades.For a highly loaded low pressure compressor cascade,called V103...As an effective method to influence end wall flow field,non-axisymmetric profiled end wall can improve the aerodynamic performance of compressor cascades.For a highly loaded low pressure compressor cascade,called V103,the study found the optimal non-axisymmetric profiled end wall decreases total pressure loss coefficient by 4.57%,5.48%and 3.04%under incidences of–3°,0°,and 3°,respectively,compared with those of the planar end wall.The optimal non-axisymmetric profiled end wall changes the structure of secondary flow in hub region,generating a corner vortex near suction surface,inhibiting the development of the passage vortex towards suction surface and reducing flow separation.When the inlet Mach numbers are 0.62 and 0.72,the total pressure loss coefficient decreases by 3.19%and 4.58%for optimal non-axisymmetric profiled end wall compared with those of the planar end wall.Though optimal non-axisymmetric profiled end wall increases total pressure loss near hub region in blade passage under different inlet Mach numbers,the peak value and region of high loss coefficient above 10%span in blade passage significantly decrease.In addition,different incidences affect the secondary flow streamlines and vortex structure near the cascade hub region,however,different inlet Mach numbers hardly change the secondary flow streamlines and vortex structure.In short,the optimal non-axisymmetric profiled end wall shows better aerodynamic performance than the planar end wall for the highly loaded compressor cascade in multi-conditions.展开更多
The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical simulation.The partitioned profile is mainly composed of a pressure-side convex structure near the lea...The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical simulation.The partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the passage.The influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is analyzed.In this paper,air(ideal gas)is selected as the flow media.The average static pressure at the outlet and the average total temperature at the inlet are kept constant.SST γ-θ is used as the turbulence model.The results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively limited.The suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction corner.Consequently,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.展开更多
基金sponsored by the National Natural Science Foundation of China(No.52106057)the National Major Science and Technology Projects of China(No.2017-Ⅱ-0001-0013)+2 种基金Fundamental Research Funds for the Central Universities of China(No.D5000210483)the Foundation of State Level Key Laboratory of Airfoil and Cascade Aerodynamics of China(Nos.D5150210006 and D5050210015)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University of China(No.CX2023012).
文摘To overcome the limitations posed by three-dimensional corner separation,this paper proposes a novel flow control technology known as passive End-Wall(EW)self-adaptive jet.Two single EW slotted schemes(EWS1 and EWS2),alongside a combined(COM)scheme featuring double EW slots,were investigated.The results reveal that the EW slot,driven by pressure differentials between the pressure and suction sides,can generate an adaptive jet with escalating velocity as the operational load increases.This high-speed jet effectively re-excites the local low-energy fluid,thereby mitigating the corner separation.Notably,the EWS1 slot,positioned near the blade leading edge,exhibits relatively low jet velocities at negative incidence angles,causing jet separation and exacerbating the corner separation.Besides,the EWS2 slot is close to the blade trailing edge,resulting in massive low-energy fluid accumulating and separating before the slot outlet at positive incidence angles.In contrast,the COM scheme emerges as the most effective solution for comprehensive corner separation control.It can significantly reduce the total pressure loss and improve the static pressure coefficient for the ORI blade at 0°-4° incidence angles,while causing minimal negative impact on the aerodynamic performance at negative incidence angles.Therefore,the corner stall is delayed,and the available incidence angle range is broadened from -10°--2°to -10°-4°.This holds substantial promise for advancing the aerodynamic performance,operational stability,and load capacity of future highly loaded compressors.
基金supported by the National Natural Science Foundation of China(No.51606187 and No.51706223)the National Major Science and Technology Project of China(Grant No.2019-II-0004-0024)。
文摘As an effective method to influence end wall flow field,non-axisymmetric profiled end wall can improve the aerodynamic performance of compressor cascades.For a highly loaded low pressure compressor cascade,called V103,the study found the optimal non-axisymmetric profiled end wall decreases total pressure loss coefficient by 4.57%,5.48%and 3.04%under incidences of–3°,0°,and 3°,respectively,compared with those of the planar end wall.The optimal non-axisymmetric profiled end wall changes the structure of secondary flow in hub region,generating a corner vortex near suction surface,inhibiting the development of the passage vortex towards suction surface and reducing flow separation.When the inlet Mach numbers are 0.62 and 0.72,the total pressure loss coefficient decreases by 3.19%and 4.58%for optimal non-axisymmetric profiled end wall compared with those of the planar end wall.Though optimal non-axisymmetric profiled end wall increases total pressure loss near hub region in blade passage under different inlet Mach numbers,the peak value and region of high loss coefficient above 10%span in blade passage significantly decrease.In addition,different incidences affect the secondary flow streamlines and vortex structure near the cascade hub region,however,different inlet Mach numbers hardly change the secondary flow streamlines and vortex structure.In short,the optimal non-axisymmetric profiled end wall shows better aerodynamic performance than the planar end wall for the highly loaded compressor cascade in multi-conditions.
基金the financial support provided by the National Science and Technology Major Project(J2019-Ⅳ-0008-0076,No.2019-Ⅱ-0010-0030)Natural Science Fund for Excellent Young Scholars of Heilongjiang Province(No.YQ2021E023)。
文摘The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical simulation.The partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the passage.The influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is analyzed.In this paper,air(ideal gas)is selected as the flow media.The average static pressure at the outlet and the average total temperature at the inlet are kept constant.SST γ-θ is used as the turbulence model.The results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively limited.The suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction corner.Consequently,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.
