【摘要】 对比研究了直叶片叶栅与弯叶片叶栅吸力面角区和下端壁流场显示的不同表现,发现弯叶片对角区分离流结构影响较大,它对减小端区马蹄涡尺度和减弱横向二次流作用明显。将不同叶栅中三维流向涡(通道涡和集中脱落涡)沿流向截面内的位置与强度作为研究对象,细致地分析了在采用弯叶片前后涡位置和强度的变化,分析表明两种涡的位置受弯叶片影响较大;通道涡沿流向的强度变化受弯叶片影响较为明显,而集中脱落涡强度受弯叶片影响却很小。来流马赫数、叶型折转角和稠度在一定范围内对弯叶片作用有规律性影响:当马赫数为0.7时,最佳弯角弯叶片降低损失7%,而马赫数为0.2时,最佳弯角弯叶片降低损失仅4%。更多还原

【Abstract】 After a contrast study of the different phenomena displayed at the suction-side corner zone and at the lower end-wall flow field by the straight-blade cascades and bowed blade ones it has been found that the bowed blades exercise a relatively great influence on the separation flow structure at the corner zone.The bowed blades can also significantly lower the dimensions of horseshoe vortex and weaken the transverse secondary-flow near the end-wall zone.With the location and intensity of three-dimensional flow-oriented vortices(passage vortex and concentrated shed vortex) in different cascades and in sections along the flow direction serving as an object of investigation a detailed analysis was conducted of the variation of vortex location and intensity prior to and after the adoption of the bowed blades.The results of the analysis indicate that the location of two kinds of vortex is subject to a relatively great influence of the bowed blades.The variation of the intensity of the passage vortex along the flow direction due to the influence of bowed blades is comparatively evident while the influence of the bowed blades on the intensity of concentrated shed vortex is very small.Mach number of an incident flow,the turning angle of a blade profile and solidity exercise in a certain range a regular influence on the function of the bowed blades.At a Mach number of 0.7 the bowed blades with an optimal curved angle will lower losses by 7%.When the Mach number is 0.2,the above-mentioned blades can reduce the losses by only 4%.更多还原