Research on aerodynamic optimization design of low-pressure turbine cascades at low Reynolds numbers environments
-
摘要:
为实现低压涡轮在低雷诺数环境下稳定工作，采用数值仿真和试验方法，从雷诺数、载荷系数、来流约化频率和湍流度影响因素方面，分析了低压涡轮叶栅的工作特性，并开展适应低雷诺数工作环境的优化设计。结果表明：随着雷诺数降低，约化频率的影响增加；雷诺数在1.0×104时，约化频率由1.03增加到3.09，效率降低0.9%，损失增加6.0%。优化后的叶栅方案降低了叶片吸力面喉部后逆压梯度，有效抑制了低雷诺数环境下的分离流动，使涡轮叶栅性能大幅提高。低雷诺数环境下，优化后叶栅吸力面无气流分离，压力和能量损失减小30%～40%；高雷诺数环境下无改善；来流攻角在−20°～10°范围内压力和能量损失增加5%～25%，但在−10°～0°时损失相当。
Abstract:To ensure stable operation of the low-pressure turbine under low-Reynolds-number conditions, numerical simulation and experimental methods were adopted to analyze the operating characteristics of the low-pressure turbine cascade with respect to influencing factors including Reynolds number, load coefficient, incoming flow reduced frequency, and turbulence intensity, and further carry out optimal design adapted to the low-Reynolds-number working environment. The results showed that with the decrease in Reynolds number, the influence of reduced frequency increased; when the Reynolds number was 1.0×104, the reduced frequency increased from 1.03 to 3.09, leading to a 0.9% reduction in efficiency and a 6.0% increase in loss. The optimized cascade scheme reduced the adverse pressure gradient downstream of the throat on the blade suction surface, effectively suppressed the separated flow under low-Reynolds-number conditions, and thus significantly improved the performance of the turbine cascade. Under low-Reynolds-number conditions, there was no airflow separation on the suction surface of the optimized cascade, and the pressure and energy losses were reduced by 30%—40%; no improvement was observed under high-Reynolds-number conditions. Within the range of incoming flow angle of attack from −20° to 10°, the pressure and energy losses increased by 5%—25%, while the losses remained nearly the same when the angle of attack was between −10° and 0°.
-
Key words:
- low Reynolds number /
- cascade /
- airfoil optimization /
- flow separation /
- low-pressure turbine
-
图 4 验证用低压涡轮子午面流道示意图
Figure 4. Meridional flow passage for low-pressure turbine verification
图 5 低压涡轮级交界面静压与试验数据对比
Figure 5. Comparison of static pressure at the interface of low-pressure turbine stage with experimental data
图 6 稳态叶片表面等熵马赫数分布
Figure 6. Steady-state isentropic Mach number distribution on the blade surface
图 8 叶片表面等熵马赫数分布（Zw=1.26, 时均值）
Figure 8. Isentropic Mach number distribution on the blade surface （Zw=1.26, time-averaged value）
图 9 叶片表面切应力（Zw=1.26，时均值）
Figure 9. Blade surface shear stress （Zw=1.26, time averaged）
图 10 一个周期内功率和流量变化（Zw=1.01, fr=2.07, Re=2×105）
Figure 10. Changes in power and flow rate within one cycle （Zw=1.01, fr =2.07, Re=2×105）
图 17 不同时刻吸力面切应力（Zw=1.44）
Figure 17. Isentropic Mach numbers on the suction surface at different times （Zw=1.44）
图 20 优化前后叶栅表面等熵马赫数
Figure 20. Surface isentropic Mach number of blade cascades before and after optimization
图 21 不同马赫数下叶片表面等熵马赫数分布
Figure 21. Isentropic Mach number distribution on blade surface at different exit Mach numbers
图 22 总压和能力损失随出口马赫数变化
Figure 22. Variation of total pressure and energy loss with outlet Mach number
图 23 不同雷诺数下叶片表面等熵马赫数分布
Figure 23. Isentropic Mach number distribution on blade surface at different Reynolds numbers
图 24 总压和能量损失随雷诺数变化
Figure 24. Variation of total pressure and energy loss with Reynolds number
图 25 不同攻角时叶片表面等熵马赫数
Figure 25. Isentropic Mach number on blade surface at different incidence angles
图 27 总压和能量损失随攻角变化
Figure 27. Variation of total pressure and energy loss with incidence degree
表 1 计算模型
Table 1. Computational model
序号 Zw fr 1 1.01 0 2 1.01 1.03 3 1.01 2.07 4 1.01 3.09 5 1.26 0 6 1.26 1.03 7 1.26 2.07 8 1.26 3.09 9 1.44 0 10 1.44 1.03 11 1.44 2.07 12 1.44 3.09 
下载: 导出CSV
表 2 仿真动叶叶栅主要参数
Table 2. Main parameters of simulated moving blade cascade
参数 叶栅A 叶栅B 叶栅C Zw 1.01 1.26 1.44 叶片数占比/% 100 80 70 安装角/（°） 30.5 35.5 40.5
下载: 导出CSV
表 3 计算时间步
Table 3. Computational time step
参数 叶栅A 叶栅B 叶栅C 动叶通道时间步 30 35 40 周期数 18 16 14 总时间步 540 560 560
下载: 导出CSV
表 4 仿真计算与试验数据对比
Table 4. Comparison of computational results and test data
参数 仿真计算 试验数据 流量/（kg/s） 28.13 28.4 膨胀比 4.37 4.37 效率 0.921 0.915
下载: 导出CSV
表 5 优化前后叶栅主要参数
Table 5. Main parameters of the cascade before and after optimization
参数 优化前 优化后 弦长/mm 28 29 安装角/（°） 62 60 栅距/mm 21 进口气流角/（°） 70 出口气流角/（°） 38.5
下载: 导出CSV
-
[1] SONDERGAARD R. High work, high-efficiency turbines for uninhabited aerial vehicles: AFRL-RQ-WP-TR-2013-0198 [R]. Dayton, US: Air Force Research Laboratory, 2013. [2] VICTOR X D S. Sensitivity of numerical simulations of low-Reynolds number flow over the T106 turbine blade[C]//Proceedings of ASME Turbo Expo: Power for Land, Sea, and Air. Glasgow, UK: ASME, 2010: 883-890. [3] 邹正平, 叶建, 刘火星, 等. 低压涡轮内部流动及其气动设计研究进展[J]. 力学进展, 2007, 37(4): 551-562. ZOU Zhengping, YE Jian, LIU Huoxing, et al. Research progress on low pressure turbine internal flows and related aerodynamic design[J]. Advances in Mechanics, 2007, 37(4): 551-562. (in Chinese doi: 10.3321/j.issn:1000-0992.2007.04.005ZOU Zhengping, YE Jian, LIU Huoxing, et al. Research progress on low pressure turbine internal flows and related aerodynamic design[J]. Advances in Mechanics, 2007, 37(4): 551-562. (in Chinese) doi: 10.3321/j.issn:1000-0992.2007.04.005 [4] HODSON H, HUNTSMAN I, STEELE A B. Aerodynamic design of low pressure turbines: AGARD-LS-167 [R]. Paris, France: Advisory Group for Aerospace Research and Development (AGARD), 1984. [5] SIEVERDING C H, BAGNERA C, BOEGE A C, et al. Investigation of the effectiveness of various types of boundary layer transition elements of low Reynolds number turbine blading: AMSE Paper GT2004-54103[R]. Vienna, Austria: ASME, 2004. [6] 邹正平, 宁方飞, 刘火星, 等. 雷诺数对涡轮叶栅流动的影响[J]. 工程热物理学报, 2004, 25(2): 216-219. ZOU Zhengping, NING Fangfei, LIU Huoxing, et al. Effect of Reynolds number on turbine cascade flow[J]. Journal of Engineering Thermophysics, 2004, 25(2): 216-219. (in ChineseZOU Zhengping, NING Fangfei, LIU Huoxing, et al. Effect of Reynolds number on turbine cascade flow[J]. Journal of Engineering Thermophysics, 2004, 25(2): 216-219. (in Chinese) [7] 伊进宝, 乔渭阳, 王占学. 低雷诺数涡轮叶栅损失的实验与数值模拟研究[J]. 西北工业大学学报, 2004, 22(5): 550-553. YI Jinbao, QIAO Weiyang, WANG Zhanxue. Experimental and numerical investigation of loss inTurbine cascade with low Reynolds number[J]. Journal of Northwestern Polytechnical University, 2004, 22(5): 550-553. (in Chinese doi: 10.3969/j.issn.1000-2758.2004.05.003YI Jinbao, QIAO Weiyang, WANG Zhanxue. Experimental and numerical investigation of loss inTurbine cascade with low Reynolds number[J]. Journal of Northwestern Polytechnical University, 2004, 22(5): 550-553. (in Chinese) doi: 10.3969/j.issn.1000-2758.2004.05.003 [8] 杨林, 乔渭阳, 罗华玲, 等. 低雷诺数高负荷低压涡轮叶型的气动设计[J]. 航空动力学报, 2013, 28(5): 1019-1028. YANG Lin, QIAO Weiyang, LUO Hualing, et al. Aerodynamic design of highly-loaded blade in low-pressure turbine with low Reynolds number[J]. Journal of Aerospace Power, 2013, 28(5): 1019-1028. (in ChineseYANG Lin, QIAO Weiyang, LUO Hualing, et al. Aerodynamic design of highly-loaded blade in low-pressure turbine with low Reynolds number[J]. Journal of Aerospace Power, 2013, 28(5): 1019-1028. (in Chinese) [9] 乔渭阳, 赵磊, 罗华玲, 等. 低雷诺数涡轮叶片边界层转捩及分离特性测量[J]. 推进技术, 2012, 33(6): 859-865. QIAO Weiyang, ZHAO Lei, LUO Hualing, et al. Measurement of the transition and separation for turbine blade boundary layer with low-Reynolds number[J]. Journal of Propulsion Technology, 2012, 33(6): 859-865. (in Chinese doi: 10.13675/j.cnki.tjjs.2012.06.013QIAO Weiyang, ZHAO Lei, LUO Hualing, et al. Measurement of the transition and separation for turbine blade boundary layer with low-Reynolds number[J]. Journal of Propulsion Technology, 2012, 33(6): 859-865. (in Chinese) doi: 10.13675/j.cnki.tjjs.2012.06.013 [10] LI Wen, ZHU Yangli, TAO Hailiang, et al. Aerodynamic characteristics of low pressure turbine under high altitude and low Reynolds number[J]. Journal of Mechanical Engineering, 2013, 49(4): 128-133. doi: 10.3901/jme.2013.04.128 [11] SONODA T, SCHREIBER H A. Aerodynamic characteristics of supercritical outlet guide vanes at low Reynolds number conditions[J]. Journal of Turbomachinery, 2007, 129(4): 694-704. doi: 10.1115/1.2720868 [12] HODSON H P, HOWELL R J. The role of transition in high-lift low-pressure turbines for aeroengines[J]. Progress in Aerospace Sciences, 2005, 41(6): 419-454. doi: 10.1016/j.paerosci.2005.08.001 [13] ZHANG W H, ZOU Z P, ZHOU K, et al. Effects of periodic wakes and freestream turbulence on coherent structures in low-pressure turbine boundary layer: ASME Paper GT2012-69061 [R] Copenhagen, Denmark: ASME , 2012. [14] 向欢, 杨荣菲, 葛宁. 尾迹诱导下低压涡轮边界层转捩的数值模拟[J]. 燃气涡轮试验与研究, 2013, 26(3): 29-33, 62. XIANG Huan, YANG Rongfei, GE Ning. Numerical simulation of wake-induced boundary layer transition in low-pressure turbine[J]. Gas Turbine Experiment and Research, 2013, 26(3): 29-33, 62. (in Chinese doi: 10.3969/j.issn.1672-2620.2013.03.006XIANG Huan, YANG Rongfei, GE Ning. Numerical simulation of wake-induced boundary layer transition in low-pressure turbine[J]. Gas Turbine Experiment and Research, 2013, 26(3): 29-33, 62. (in Chinese) doi: 10.3969/j.issn.1672-2620.2013.03.006 [15] ANTORANZ A, CALZADA P D L. Linear and non-linear simulations of the wake-bubble interaction and the generated surface pressure fluctuations on high lift turbine profiles: ASME Paper GT2004-53223 [R]. Vienna, Austria: ASME, 2004. [16] CURTIS E M, HODSON H P, BANIEGHBAL M R, et al. Development of blade profiles for low-pressure turbine applications[J]. Journal of Turbomachinery, 1997, 119(3): 531-538. doi: 10.1115/1.2841154 [17] SCHOBEIRI M T, ÖZTÜRK B. Experimental study of the effects of periodic unsteady wake flow on boundary layer development, separation, and re-attachment along the surface of a low pressure turbine blade: ASME Paper GT2004-53929 [R]. Vienna, Austria: ASME, 2004. [18] ÖZTÜRK B, SCHOBEIRI M T, DAVID E A. Effect of Reynolds number and periodic unsteady wake flow condition on boundary layer development, separation, and re-attachment along the suction surface of a low pressure turbine blade: ASME Paper GT2005-68600 [R] Reno, US: ASME, 2005. [19] ÖZTÜRK B, SCHOEBEIRI M T. Effect of turbulence intensity and periodic unsteady wake flow condition on boundary layer development, separation, and re-attachment over the separation bubble along the suction surface of a low pressure turbine blade: ASME Paper GT 2006-91293 [R]. New York: ASME, 2006. [20] SCHOBEIRI M T, ÖZTÜRK B, ASHPIS D E. Effect of Reynolds number and periodic unsteady wake flow condition on boundary layer development, separation, and intermittency behavior along the suction surface of a low pressure turbine blade[J]. Journal of Turbomachinery, 2007, 129(1): 92-107. doi: 10.1115/1.2219762 [21] SCHULTE V, HODSON H. Wake-separation bubble interaction in low pressure turbines: AIAA1994-2931 [R]. Indianapolis, US: AIAA, 1994. [22] STIEGER R, HOLLIS D, HODSON H. Unsteady surface pressures due to wake induced transition in a laminar separation bubble on a LP turbine cascade: ASME Paper GT2003-38303 [R]. New York: ASME, 2003. [23] STIEGER R D, HODSON H. The unsteady development of a turbulent wake through a downstream low-pressure turbine blade passage[J]. Journal of Turbomachinery, 2005, 127(2): 388-394. doi: 10.1115/1.1811094 [24] LARDEAU S, LESCHZINER M A. Modeling of wake-induced transition in linear low-pressure turbine cascades[J]. AIAA Journal, 2006, 44(8): 1854-1865. doi: 10.2514/1.16470 [25] MAHALLATI A, MCAULIFFE B R, SJOLANDER S A, et al. Aerodynamics of a low-pressure turbine airfoil at low-Reynolds numbers: Part 1 steady flow measurements: ASME Paper GT2007-27347[R]. Montreal, Canada: ASME, 2007. [26] BRUNNER S, FOTTNER L, SCHIFFER H P. Comparison of two highly loaded low pressure turbine cascades under the influence of wake-induced transition: ASME Paper 2000-GT-268 [R]. Munich, Germany: ASME, 2000. [27] MAHALLATI A, SJOLANDER S A. Aerodynamics of a low-pressure turbine airfoil at low-Reynolds numbers: Part 2 blade-wake interaction: ASME Paper GT2007-27348 [R]. Montreal, Canada: ASME, 2007. [28] FUNAZAKI K I, YAMADA K, ONO T, et al. Experimental and numerical investigations of wake passing effects upon aerodynamic performance of a LP turbine linear cascade with variable solidity: ASME Paper GT2006-90507 [R]. New York: ASME, 2006. [29] FUNAZAKI K I, SHIBA T. Effects of blade loading distribution on aerodynamic performance of ultra-high lift LP turbine airfoils under the influences of wake passing and freestream turbulence: ASME Paper GT2010-22134 [R]. New York: ASME, 2010. [30] CHRISTIAN T W, REINHARD N, MARTIN H. A comparison of three low pressure turbine designs: ASME Paper GT2012-69028 [R]. Copenhagen, Denmark: ASME, 2012. [31] CHERRY D G, GAY C H, LENAHAN D T. Energy efficient engine low pressure turbine test hardware detailed design report: NASA-CR-167956 [R]. Cincinnati, US: General Electric Company, 1982. -
点击查看大图
计量
- 文章访问数: 58
- HTML浏览量: 33
- PDF量: 11
- 被引次数: 0