为揭示高负荷压气机叶栅内部流动损失的产生机理和分布规律以及等离子体气动激励的作用机制,利用拓扑分析和数值计算方法,从计算模型的建立与验证、基准流场的分离结构和等离子体流动控制3个方面展开研究;对总压损失系数分布、拓扑结构和表面流谱与空间流线分布以及旋涡结构进行分析,并开展了激励方式的优化分析.结果表明:随着攻角的增大,固壁面拓扑结构增加了3对奇点,吸力面流向激励改变了固壁面拓扑结构.当攻角为2°时,在吸力面拓扑结构中产生了一对奇点,打断了角区分离线,并引入了一条回流再附线.叶栅流道内部有5个主要涡系,尾缘径向对涡促进流体的展向流动,并成为吸力面倒流的主要组成部分;角涡是一个独立的涡系,其强度和尺度不受等离子体气动激励的影响.吸力面流向激励可以改善叶中流场,但对角区流动作用很小;端壁横向激励可以降低角区流动损失,对叶中流场作用有限;吸力面流向与端壁横向组合激励在整个叶高范围内均可以显著抑制流动分离;端壁横向流动对角区流动分离结构的影响大于吸力面附面层的分离.吸力面流向激励的优化明显降低,而端壁横向激励和组合激励的优化保持并增强了等离子体流动的控制效果.
To discover the rule of flow loss generation and distribution as well as mechanism of plasma aerodynamic actuation in highly loaded compressor cascade, research on the establishment and verification of simulation model, flow separation structure of basic flowfield and plasma flow control is conducted with topology analysis and numerical method. The total pressure loss coefficient distribution, topology structure, surface streamline patterns and three-dimensional streamlines distribution as well as vortex structure are analyzed, and analysis of optimized actuation layouts are conducted. Results show that three pairs of additional singular points of surface topology strucutre generate with the increase of angle of attack. Plasma actuation changes solid surface topology structure. One pair of additional singular point of surface topology structure ge- nerates with plasma actuation and one more reattachment line appears, which break the the separation line on suction surface at angle of attack of 2°. There are five principal vortices inside the cascade passage. The radial coupling-vortex greatly promotes the fluids carried by passage vortex to move in spanwise direction and becomes the main part of backflow on suction surface. Corner vortex exists independently and its strength and scale are hardly affected by plasma actuation. Suction surface streamwise actuation can have better effect on the flowfield near midspan than the angular region. Endwall pitchwise actuation can prevent the flow separation in corner region except for the flowfield near midspan. Combined actuation can obviously prevent the flow separation for the whole blade span. Endwall transverse movement has greater influence on flow separation structure in corner region than separated suction side boundary layer. Optimized suction side streamwise actuation obviously reduce the capability of preventing boundary layer separated flow, but the optimized endwall pitchwise actuation and combined actuation retain and enhance the performance of plasma flow control.
[1] Chen S W, Guo S, Lu H W, et al. Analysis of the aerodynamic performance of a super highly loaded adsorption type compressor cascade. Journal of Engineering for Thermal Energy & Power, 2009, 24(1): 167-171. (in Chinese) 陈绍文, 郭爽, 陆华伟, 等. 超高负荷吸附式压气机叶栅气动性能分析. 热能动力工程, 2009, 24(1): 167-171.
[2] Zheng X Q, Zhou X B, Zhou S. Investigation on a type of flow control to weaken unsteady separated flows by unsteady excitation in axial flow compressors. ASME Journal of Turbomachinery, 2005, 127(2): 489-496.
[3] Zhang Y J, Chen F, Feng G T, et al. Influence of turning angle on flow field performance of linear bowed stator in compressor at low Mach number. Chinese Journal of Aeronautics, 2006, 19(4): 271-277.
[4] Li Y H, Liang H, Ma Q Y, et al. Experimental investigation on airfoil suction side flow separation by pulse plasma aerodynamic actuation. Acta Aeronautica et Astronautica Sinica, 2008, 29(6): 1429-1435. (in Chinese) 李应红, 梁华, 马清源, 等. 脉冲等离子体气动激励抑制翼型吸力面流动分离的实验. 航空学报, 2008, 29(6): 1429-1435.
[5] Perez-Blanco H, van Dyken R, Byerley A, et al. Turbine cascade flow control using a wake filling pulsed plasma actuator. ASME GT2005-68114.
[6] Huang J H, Corke T C, Thomas F O. Unsteady plasma actuators for separation control of low-pressure turbine blades. AIAA Journal, 2006, 44(7): 1477-1487.
[7] Wu Y, Li Y H, Zhu J Q, et al. Experimental investigation of a subsonic compressor with plasma actuation treated casing. AIAA-2007-3849, 2007.
[8] Wu Y, Li Y H, Zhu J Q, et al. Experimental investigation of using plasma aerodynamic actuation to extend low-speed axial compressor's stability. Journal of Aerospace Power, 2007, 22(12): 2025-2030. (in Chinese) 吴云, 李应红, 朱俊强, 等. 等离子体气动激励扩大低速轴流压气机稳定性的实验研究. 航空动力学报, 2007, 22(12): 2025-2030.
[9] Vo H D. Control of rotating stall in axial compressors using plasma actuators. AIAA-2007-3845, 2007.
[10] Lewin E, Koulovic D, Stark U. Experimental and numerical analysis of hub-corner stall in compressor cascades. ASME GT2010-22704.
[11] Nerger D, Saathoff H, Radespiel R, et al. Experimental investigation of endwall and suction side blowing in a highly loaded compressor stator cascade. ASME GT2010-22578.
[12] Porter C O, Enloe C L, Mclaughlin T E, et al. Boundary layer control using a DBD plasma actuator. AIAA-2007-0786, 2007.
[13] Dorfner C, Hergt A, Nicke E, et al. Advance non-axisymmetric endwall contouring for axial compressors by generating an aerodynamic separator—Part I: principal cascade design and compressor application. ASME GT2009-59383.
[14] Benard N, Jolibois J, Moreau E. Lift and drag performances of an axisymmetric airfoil controlled by plasma actuator. Journal of Electrostatics, 2009, 67(2-3): 133-139.
[15] Kang S, Wang Z Q. An application of topological analysis to studying the three-dimensional flow in cascade;part I—Topological rules for skin-friction lines and section streamlines. Applied Mathematics and Mechanics, 1990, 11(5): 457-462.
[16] Zhang Y J, Wang H S, Xu J Z, et al. Research on topology and vortex structure in diffuser cascades. Science Chinese, Series E: Technological Science, 2009, 39(5): 1016-1025. (in Chinese) 张永军, 王会社, 徐建中, 等. 扩压叶栅中拓扑和漩涡结构的研究. 中国科学, E辑: 技术科学, 2009, 39(5): 1016-1025.
[17] Zhao X H, Li Y H, Yue T P, et al. Experimental investigation of flow separation control on highly loaded compressor cascade by plasma aerodynamic actuation. High Voltage Engineering, 2011, 37(6): 1521-1527. (in Chinese) 赵小虎, 李应红, 岳太鹏, 等. 等离子体气动激励抑制高负荷压气机叶栅流动分离的实验研究. 高电压技术, 2011, 37(6): 1521-1527.
[18] Han W J, Yang Q H. Topology and vortex structures of turbine cascade with different tip clearance. Chinese Journal of Aeronautics, 2002, 15(1): 18-26.
[19] Zhang H X, Deng X G. A nalytic studies for three-dimensional steady separated flows and vortex motion. Acta Aerodynamic Sinica, 1992, 10(1): 8-12. (in Chinese) 张涵信, 邓小刚. 三维定常分离流和涡运动的定性分析研. 空气动力学报, 1992, 10(1): 8-12.
[20] Seraudie A, Aubert E, Naude N, et al. Effect of plasma actuators on a flat plate laminar boundary layer in subsonic condition. AIAA-2006-3350, 2006.
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