The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach...The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach narrows the spacing between the stator and the strut,making traditional research on transition ducts only with struts unsuitable.The numerical results and experimental oil flow visualization results were utilized to reconstruct the three-dimensional flow structures in the stator passages under various operating conditions.Additionally,numerical methods were employed to analyze the mechanisms of the strut's effect on the upstream stator in an aggressive transition duct.The results show that the strut potential field increases the load on the upstream stator,leading to severe blade surface separation and corner separation/stall,and redistributes the inflow angle of the upstream stators circumferentially,resulting in significant differences in the flow structures within the stator passages on both sides.The separation flows within the stator passages mainly manifest in five types:pressure surface separation vortex,suction surface concentrated shedding vortex,suction surface separation vortex,suction surface-corner stall separation vortex,and suction surface separation vortex pair.Under different operating conditions,the separation flows within the stator passages are always composed of a part of these five types or a transitional state between two of them.展开更多
为探究环下润滑供油通道滑油流量分配特性,采用volume of fluid(VOF)方法对轴心射流收油环内部两相流动进行了计算,获得了供油通道内油膜形成过程与流场特征,重点讨论了供油温度、主轴转速、供油流量及供油孔径组合对流量分配的影响规律...为探究环下润滑供油通道滑油流量分配特性,采用volume of fluid(VOF)方法对轴心射流收油环内部两相流动进行了计算,获得了供油通道内油膜形成过程与流场特征,重点讨论了供油温度、主轴转速、供油流量及供油孔径组合对流量分配的影响规律,建立了临界孔径比的无量纲关联式。结果表明:滑油射流冲击收油环中心后形成油膜,其边缘断裂形成油带、油矢甩至侧壁面,最终油膜铺满整个端面;计算工况范围内,滑油分配主要受供油流量及孔径影响,各出口流量随供油流量上升均呈线性增加,滑油分配比随供油流量增加而平均降低15.05%;滑油分配比随下游孔径与孔径比的增加而上升;当无量纲供油流量越大且下游无量纲孔径越小时,临界孔径比越高并趋近于1,当无量纲供油流量降低或下游无量纲孔径增大时,临界孔径比则下降。展开更多
基金supported by the National Natural Science Foundation of China(No.52276025)the Science Center for Gas Turbine Project of China(Nos.P2022-A-Ⅱ-001-001,P2022-A-Ⅱ-002-001 and P2022-B-Ⅱ-002-001)。
文摘The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach narrows the spacing between the stator and the strut,making traditional research on transition ducts only with struts unsuitable.The numerical results and experimental oil flow visualization results were utilized to reconstruct the three-dimensional flow structures in the stator passages under various operating conditions.Additionally,numerical methods were employed to analyze the mechanisms of the strut's effect on the upstream stator in an aggressive transition duct.The results show that the strut potential field increases the load on the upstream stator,leading to severe blade surface separation and corner separation/stall,and redistributes the inflow angle of the upstream stators circumferentially,resulting in significant differences in the flow structures within the stator passages on both sides.The separation flows within the stator passages mainly manifest in five types:pressure surface separation vortex,suction surface concentrated shedding vortex,suction surface separation vortex,suction surface-corner stall separation vortex,and suction surface separation vortex pair.Under different operating conditions,the separation flows within the stator passages are always composed of a part of these five types or a transitional state between two of them.
文摘为探究环下润滑供油通道滑油流量分配特性,采用volume of fluid(VOF)方法对轴心射流收油环内部两相流动进行了计算,获得了供油通道内油膜形成过程与流场特征,重点讨论了供油温度、主轴转速、供油流量及供油孔径组合对流量分配的影响规律,建立了临界孔径比的无量纲关联式。结果表明:滑油射流冲击收油环中心后形成油膜,其边缘断裂形成油带、油矢甩至侧壁面,最终油膜铺满整个端面;计算工况范围内,滑油分配主要受供油流量及孔径影响,各出口流量随供油流量上升均呈线性增加,滑油分配比随供油流量增加而平均降低15.05%;滑油分配比随下游孔径与孔径比的增加而上升;当无量纲供油流量越大且下游无量纲孔径越小时,临界孔径比越高并趋近于1,当无量纲供油流量降低或下游无量纲孔径增大时,临界孔径比则下降。
