涡轮叶片冷却孔电解加工电解液流场CFD分析研究
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摘要
以航空发动机涡轮叶片常用材料高温镍基合金Inconel718为基材进行气膜冷却孔电解加工试验,通过30组对比试验,以短路次数和单边间隙△_s作为性能评价指标,探讨了加工电压U和电解液浓度ζ对冷却孔加工效率和加工精度的影响规律。基于CFD软件,进一步着重研究了电解液速度及涡流等因素对冷却孔加工的影响规律。CFD分析得出:随着电解液浓度的升高,速度场分布均匀,涡流变化梯度增大,加工稳定性提高,加工精度降低;随着电压的升高,冷却孔锥度变大,加工精度较低,涡流变化较小,当电压较大时,较多气体析出,导致速度场分布不均匀且不连续,加工稳定性变差。
Film cooling holes were obtained by electrochemical machining using Inconel718 nickel-based super-alloy which is commonly used for turbine blade of aero-engine. Under different parameters( voltage U,concentration of electrolyte ζ),30 sets of orthogonal experiments were conducted on the machining efficiency and machining accuracy. This paper studies the electrolyte flow rate and eddy currenton electrolyte cooling holes processing accuracy and stability of the law. The results: while the concentration increasing,velocity distribution was uniform and eddy current was various,worse processing stability could be improved and processing forming was worse; while the voltage increased,the taper of cooling hole was increased obviously and processing accuracy was worse. With the higher voltage,the gas bubble evolution introduced the discontinuity and periodic fluctuation of filed fluid,worse processing stability.
Film cooling holes were obtained by electrochemical machining using Inconel718 nickel-based super-alloy which is commonly used for turbine blade of aero-engine. Under different parameters( voltage U,concentration of electrolyte ζ),30 sets of orthogonal experiments were conducted on the machining efficiency and machining accuracy. This paper studies the electrolyte flow rate and eddy currenton electrolyte cooling holes processing accuracy and stability of the law. The results: while the concentration increasing,velocity distribution was uniform and eddy current was various,worse processing stability could be improved and processing forming was worse; while the voltage increased,the taper of cooling hole was increased obviously and processing accuracy was worse. With the higher voltage,the gas bubble evolution introduced the discontinuity and periodic fluctuation of filed fluid,worse processing stability.
引文
[1]Li Zhiyong,Niu Zongwei.Convergence analysis of the numerical solution for cathode design of aero-engine blades in electrochemical machining[J].Chinese Journal of Aeronautics,2007,20(6):570-576.
[2]Wang M H,Zhu D.Machining of turbulated cooling holes in aero-engine blades and their heat transfer analysis[J].Mechanical Science and Technology,2006,25:1347-1350.
[3]朱海南,齐歆霞.涡轮叶片气膜孔加工技术及其发展[J].航空制造技术,2011(13):71-74.
[4]Skoczypiec S.Research on ultrasonically assisted electrolytic machining process[J].International Journal of Advanced Manufacture Technology,2011,52(5/8):565-574.
[5]Okasha M M,Mativenga P T,Driver N,et al.Sequential laser and me-chanical micro-drilling of Ni super alloy for aerospace application[J].CIRP Annals-Manufacturing Technology,2010,59(1):199-202.
[6]刘新灵,陶春虎,刘春江,等.航空发动机叶片气膜孔加工方法及其演变分析[J].材料导报,2013,27(11):117-120.
[7]路文文,李志永,崔庆伟,等.酒石酸钠对叶片冷却孔电解加工的影响研究[J].制造技术与机床,2016(8):115-119.
[8]孙建军,李志永,臧传武.航空发动机气膜冷却孔的电解加工[J].电镀与涂饰,2015,34(11):626-631.
[9]王维,朱荻,曲宁松,等.管电极电解加工工艺工程稳定性研究[J].机械工程学报,2010,46(11):179-184.
[10]章本照,印建安,张宏基.流体力学数值方法[M].北京:机械工业出版社,2003.
[2]Wang M H,Zhu D.Machining of turbulated cooling holes in aero-engine blades and their heat transfer analysis[J].Mechanical Science and Technology,2006,25:1347-1350.
[3]朱海南,齐歆霞.涡轮叶片气膜孔加工技术及其发展[J].航空制造技术,2011(13):71-74.
[4]Skoczypiec S.Research on ultrasonically assisted electrolytic machining process[J].International Journal of Advanced Manufacture Technology,2011,52(5/8):565-574.
[5]Okasha M M,Mativenga P T,Driver N,et al.Sequential laser and me-chanical micro-drilling of Ni super alloy for aerospace application[J].CIRP Annals-Manufacturing Technology,2010,59(1):199-202.
[6]刘新灵,陶春虎,刘春江,等.航空发动机叶片气膜孔加工方法及其演变分析[J].材料导报,2013,27(11):117-120.
[7]路文文,李志永,崔庆伟,等.酒石酸钠对叶片冷却孔电解加工的影响研究[J].制造技术与机床,2016(8):115-119.
[8]孙建军,李志永,臧传武.航空发动机气膜冷却孔的电解加工[J].电镀与涂饰,2015,34(11):626-631.
[9]王维,朱荻,曲宁松,等.管电极电解加工工艺工程稳定性研究[J].机械工程学报,2010,46(11):179-184.
[10]章本照,印建安,张宏基.流体力学数值方法[M].北京:机械工业出版社,2003.