Investigations on desensitization of blade tip clearance variation in turbine blades
-
摘要: 采用数值方法联合标准k-ω两方程湍流模型求解雷诺平均Navier-Stokes方程组,研究了平顶和分别采用被动、主动以及复合间隙控制方法的凹槽顶、平顶喷气、凹槽顶喷气4种不同叶顶结构下涡轮性能对叶顶间隙变化的敏感性,分析了间隙变化对间隙流场结构及损失的影响,研究了涡轮性能随叶顶间隙变化的规律,并对采用不同间隙控制方法的叶顶结构所带来的效率收益对攻角变化敏感性进行了评估.结果表明:在不同间隙控制方法下叶顶泄漏涡强度随间隙的增加速度变缓,尤其在复合间隙控制方法下更为明显,从而使得在复合间隙控制方法下涡轮性能对间隙变化的敏感度最低;仅仅涡轮叶片前缘区域泄漏流动对攻角变化比较敏感,使得凹槽顶结构具有最佳的攻角变化适应性.Abstract: Numerical investigation was performed to simulate the sensitivity of turbine performance to blade tip clearance variation for four different tips including flat tip and other three tips: cavity tip, flat tip with injection and cavity tip with injection; passive, active and compound clearance control methods were used respectively by solving Reynolds-averaged Navier-Stokes equations in conjunction with a standard k-ω two-equation turbulence model. The influences on the clearance flow structure and losses caused by tip clearance variation were analyzed. In addition, the variation of the turbine performance which changes by the different clearances was investigated. Furthermore, the sensitivities of the efficiency-gains caused by different clearance control methods to changes in incidence angles were assessed. Results show that, with different clearance control methods, the growth rate of the strength of tip leakage vortex slows down, especially for the compound clearance control method. This leads to the results that the compound clearance control method presents the lowest sensitivity of turbine performance to clearance variation. In addition, only the leakage flows over the front part of the blade are sensitive to incidence angle variation, which causes the best adaptability of cavity tip to incidence angle variation.
-
[1] Bunker R S.Axial turbine blade tips:function,design,and durability[J].Journal of Propulsion and Power,2006,22(2):271-285. [2] Lattime S B,Steinetz B M.High-pressure-turbine clearance control systems:current practices and future directions[J].Journal of Propulsion and Power,2004,20(2):302-311. [3] Xiao X W,McCarter A A,Lakshminarayana B.Tip clearance effects in a turbine rotor:Part Ⅰ pressure field and loss[J].Journal of Turbomachinery,2001,123(2):296-304. [4] McCarter A A,Xiao X W,Lakshminarayana B.Tip clearance effects in a turbine rotor:Part Ⅱ velocity field and flow physics[J].Journal of Turbomachinery,2001,123(2):305-313. [5] 邹正平,綦蕾,李维,等.上游尾迹与涡轮转子泄漏流相互作用数值模拟[J].航空动力学报,2010,25(1):58-66. ZOU Zhengping,QI Lei,LI Wei,et al.Numerical simulations of upstream wake-tip leakage vortex interactions in turbine rotor[J].Journal of Aerospace Power,2010,25(1):58-66.(in Chinese) [6] Nho Y C,Park J S,Lee Y J,et al.Effects of turbine blade tip shape on total pressure loss and secondary flow of a linear turbine cascade[J].International Journal of Heat and Fluid Flow,2012,33(1):92-100. [7] Lee S W,Kim S U,Kim K H.Aerodynamic performance of winglets covering the tip gap inlet in a turbine cascade[J]. International Journal of Heat and Fluid Flow,2012,34:36-46. [8] Tallman J,Lakshminarayana B.Methods fordesensitizing tip clearance effects in turbines[R].ASME Paper 2001-GT-0486,2001. [9] Gao J,Zheng Q,Yue G Q.Reduction of tip clearance losses in an unshrouded turbine by rotor-casing contouring[J].Journal of Propulsion and Power,2012,28(5):936-945. [10] Niu M S,Zang S S.Experimental and numerical investigations of tip injection on tip clearance flow in an axial turbine cascade[J].Experimental Thermal and Fluid Science,2011,35(6):1214-1222. [11] Van Ness D K,Corke T C,Morris S C.Turbine tip clearance flow control using plasma actuators[R].AIAA-2006-0021,2006. [12] DeCastro J A,Melcher K J.A study on the requirements for fast active turbine tip clearance control systems[R].NASA/TM-2004-213121,2004. [13] Zhou C,Hodson H.The tip leakage flow of an unshrouded high pressure turbine blade with tip cooling[J].Journal of Turbomachinery,2011,133(4):041028.1-041028.12. [14] 王大磊,朴英.叶尖间隙高度对某高压涡轮级损失分布的影响[J].航空动力学报,2012,27(1):169-175. WANG Dalei,PIAO Ying.Influence of tip clearance size on flow losses of a transonic high pressure turbine stage[J].Journal of Aerospace Power,2012,27(1):169-175.(in Chinese) [15] 杨佃亮,丰镇平.叶顶凹槽对燃气透平动叶气动性能及叶顶传热的影响[J].西安交通大学学报,2008,42(7):838-842. YANG Dianliang,FENG Zhenping.Effects of squealer tip on blade aerodynamic performance and tip heat transfer in gas turbine[J].Journal of Xi'an Jiaotong University,2008,42(7):838-842.(in Chinese) [16] Timko L P.Energy efficient engine high pressure turbine component test performance report[R].NASA CR-168289, 1984. [17] Ameri A A,Steinthorsson E,Rigby D L.Effect of squealer tip on rotor heat transfer and efficiency[J].Journal of Turbomachinery,1998,120(4):753-759. [18] Gao J,Zheng Q,Li Y J,et al.Effect of axially non-uniform rotor tip clearance on aerodynamic performance of an unshrouded axial turbine[J].Proceedings of the Institution of Mechanical Engineers:Part A Journal of Power and Energy,2011,226(2):231-244. [19] Azad G S,Han J C,Teng S Y,et al.Heat and pressure distributions on a gas turbine blade tip[J].Journal of Turbomachinery,2000,122(4):717-724. [20] Acharya S,Yang H T,Prakash C,et al.Study of flow and heat transfer on a blade tip with different leakage reduction strategies[R].ASME Paper GT2003-38617,2003. [21] Young J B,Horlock J H.Defining the efficiency of a cooled turbine[J].Journal of Turbomachinery,2006,128(4):658-667. [22] Yamamoto A.Endwall flow/loss mechanisms in a linear turbine cascade with blade tip clearance[J].Journal of Turbomachinery,1989,111(3):264-275.
点击查看大图
计量
- 文章访问数: 963
- HTML浏览量: 1
- PDF量: 667
- 被引次数: 0