轮缘封严气流与上游导向器非定常干涉数值研究
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摘要
为了研究涡轮转静盘腔中的轮缘封严气流与主流的非定常干涉效应,在不同封严流量下对上游导向器的流场分布和非定常特性进行了数值模拟。结果表明,封严出流的堵塞作用引起吸力面后半段轮毂附近静压的升高和熵增的减小,以及导向器出口速度的降低。从无封严腔体到RI=1.7%,5%叶高吸力面静压系数最大增加了6%。封严出流造成横向压力梯度减小使得轮毂通道涡和轮毂尾缘脱落涡的强度减弱。不存在封严气流时,燃气入侵使得10%叶高以下范围非定常波动降低;存在封严气流时,来自燃气入侵和腔体进口的封严出流的耦合作用使得非定常波动不断减弱。
To investigate unsteady interaction mechanism between the rim seal flow in turbine stator-rotor cavity and main flow,detailed unsteady numerical simulations of the flow field and unsteady characteristic of the vane were conducted under different rim seal mass flow rate. The results show the blockage effect resulting from the egress flow leads to the pressure to increase and static entropy to reduce on the latter half of suction side near the hub. From the case without a cavity to RI= 1.7%,at 5% span,the maximum pressure coefficient increase on the suction side reaches 6%. Moreover,the blockage effect causes the velocity to decrease at vane exit. Furthermore,the rim seal flow results in the decrease in lateral pressure gradient,causing the strength of hub passage vortex and hub trailing shedding vortex to reduce. Without rim seal flow,the ingress flow contributes to decreasing unsteady fluctuation from the hub to 10% span. When there is rim seal flow,unsteady fluctuation continues to reduce due to coupling effects of the egress flow from the ingress and the egress flow form the cavity inlet.
To investigate unsteady interaction mechanism between the rim seal flow in turbine stator-rotor cavity and main flow,detailed unsteady numerical simulations of the flow field and unsteady characteristic of the vane were conducted under different rim seal mass flow rate. The results show the blockage effect resulting from the egress flow leads to the pressure to increase and static entropy to reduce on the latter half of suction side near the hub. From the case without a cavity to RI= 1.7%,at 5% span,the maximum pressure coefficient increase on the suction side reaches 6%. Moreover,the blockage effect causes the velocity to decrease at vane exit. Furthermore,the rim seal flow results in the decrease in lateral pressure gradient,causing the strength of hub passage vortex and hub trailing shedding vortex to reduce. Without rim seal flow,the ingress flow contributes to decreasing unsteady fluctuation from the hub to 10% span. When there is rim seal flow,unsteady fluctuation continues to reduce due to coupling effects of the egress flow from the ingress and the egress flow form the cavity inlet.
引文
[1] LIU Huoxing,AN Yuge,ZOU Zhengping. Aerothermal Analysis of a Turbine with Rim Seal Cavity[R]. ASME 2014-GT-25276
[2] SONG Liming,ZHU Peiyuan,LI Jun,et al. Effect of Purge Flow on Endwall Flow and Heat Transfer Characteristic of a Gas Turbine Blade[J]. Applied Thermal Engineering,2017,110(3):504-520
[3] JIA Wei,LIU Huoxing. Numerical Investigation of the Effects of Rim Seal on Turbine Aerodynamic Design Parameters and End Wall Flows in Low-Aspect Ratio Turbine[J]. Computer&Fluids,2013,74(5):114-125
[4] ZENG Jun,ZHANG Weitao. Numerical Simulation of the Interaction between Rim Seal and Main Annulus Flow in a Four Stage Low-Pressure Axial Turbine[R]. AIAA-2015-3416
[5] POPOVIC I,HODSON H P. The Effects of Parametric Variation of Rim Seal Geometry on the Interaction between Hub Leakage and Mainstream Flows in HP Turbine[R].ASME 2012-GT-68025
[6] ONG J,MILLER R J,UCHIDA S. The Effects of Coolant Injection on the Endwall Flow of a High Pressure Turbine[J]. Journal of Turbomachinery,2012,134(5):051003-8
[7] BOUDET J,HILLS N J,CHEWS J W. Numerical Simulation of the Flow Interaction between Turbine Main Annulus and Disc Cavities[R]. ASME 2006-GT-90307
[8] PANIAGUA G,DENOS R,ALMEIDA S. Effect of the Hub Endwall Cavity Flow on the Flow-Field of a Transonic High-Pressure Turbine[J]. Journal of Turbomachinery,2004,126(10):578-586
[9] JENNY P,ABHARI R S,ROSA M G,et al. Unsteady Rotor Hub Passage Vortex Behavior in the Presence of Purge Flow in an Axial Low Pressure Turbine[R]. ASME 2012-GT-69256
[10]REGINA K,KALFAS A I,ABHARI R S. Experimental Investigation of Purge Flow Effects on a High Pressure Turbine Stage[J]. Journal of Turbomachinery,2014,137(4):041006-8
[11]SCHADLER R,KALFAS A I,ABHARI R S. Modulation and Radial Migration for Turbine Hub Modes by the Rim Seal Purge Flow[R]. ASME 2016-GT-56661
[12]BEHR T. Control of Rotor Tip Leakage and Secondary Flow by Casing Air Injection in Unshrouded Axial Turbines[D]. Dresden:Dresden University of Technology,2007
[13]SCHUEPBACH P. Influence of Rim Seal Purge Flow on Performance of an Endwall Profiled Axial Turbine[D]. Swiss:Swiss Federal Institute of Technology,2009
[14]张晶辉,马宏伟.轮缘封严气体对涡轮转子性能影响的非定常数值研究[J].推进技术,2014,35(4):470-478ZHANG Jinghui,MA Hongwei. Unsteady Numerical Investigation for Effects of Rim Sealing Flow on Performance of a Turbine Rotor[J]. Journal of Propulsion Technology,2014,35(4):470-478(in chinese)
[2] SONG Liming,ZHU Peiyuan,LI Jun,et al. Effect of Purge Flow on Endwall Flow and Heat Transfer Characteristic of a Gas Turbine Blade[J]. Applied Thermal Engineering,2017,110(3):504-520
[3] JIA Wei,LIU Huoxing. Numerical Investigation of the Effects of Rim Seal on Turbine Aerodynamic Design Parameters and End Wall Flows in Low-Aspect Ratio Turbine[J]. Computer&Fluids,2013,74(5):114-125
[4] ZENG Jun,ZHANG Weitao. Numerical Simulation of the Interaction between Rim Seal and Main Annulus Flow in a Four Stage Low-Pressure Axial Turbine[R]. AIAA-2015-3416
[5] POPOVIC I,HODSON H P. The Effects of Parametric Variation of Rim Seal Geometry on the Interaction between Hub Leakage and Mainstream Flows in HP Turbine[R].ASME 2012-GT-68025
[6] ONG J,MILLER R J,UCHIDA S. The Effects of Coolant Injection on the Endwall Flow of a High Pressure Turbine[J]. Journal of Turbomachinery,2012,134(5):051003-8
[7] BOUDET J,HILLS N J,CHEWS J W. Numerical Simulation of the Flow Interaction between Turbine Main Annulus and Disc Cavities[R]. ASME 2006-GT-90307
[8] PANIAGUA G,DENOS R,ALMEIDA S. Effect of the Hub Endwall Cavity Flow on the Flow-Field of a Transonic High-Pressure Turbine[J]. Journal of Turbomachinery,2004,126(10):578-586
[9] JENNY P,ABHARI R S,ROSA M G,et al. Unsteady Rotor Hub Passage Vortex Behavior in the Presence of Purge Flow in an Axial Low Pressure Turbine[R]. ASME 2012-GT-69256
[10]REGINA K,KALFAS A I,ABHARI R S. Experimental Investigation of Purge Flow Effects on a High Pressure Turbine Stage[J]. Journal of Turbomachinery,2014,137(4):041006-8
[11]SCHADLER R,KALFAS A I,ABHARI R S. Modulation and Radial Migration for Turbine Hub Modes by the Rim Seal Purge Flow[R]. ASME 2016-GT-56661
[12]BEHR T. Control of Rotor Tip Leakage and Secondary Flow by Casing Air Injection in Unshrouded Axial Turbines[D]. Dresden:Dresden University of Technology,2007
[13]SCHUEPBACH P. Influence of Rim Seal Purge Flow on Performance of an Endwall Profiled Axial Turbine[D]. Swiss:Swiss Federal Institute of Technology,2009
[14]张晶辉,马宏伟.轮缘封严气体对涡轮转子性能影响的非定常数值研究[J].推进技术,2014,35(4):470-478ZHANG Jinghui,MA Hongwei. Unsteady Numerical Investigation for Effects of Rim Sealing Flow on Performance of a Turbine Rotor[J]. Journal of Propulsion Technology,2014,35(4):470-478(in chinese)