气膜孔几何位置对旋流冷却流动与传热特性的影响

发布时间：2018-03-30 05:30

本文选题：旋流冷却　切入点：气膜孔　出处：《西安交通大学学报》2016年07期

【摘要】：为了研究气膜孔几何位置对旋流冷却特性的影响,建立了带有气膜孔的旋流腔冷却结构,利用流体动力学软件ANSYS CFX对比分析了有无气膜孔情况下旋流冷却性能的差异,并研究了气膜孔轴宽比和周向角度对旋流冷却流动和换热特性的影响。研究结果表明:气膜孔对旋流腔靶面旋流冷气运动产生强烈扰动,使气膜孔上游冷气流速增加,下游冷气流速降低;气膜孔使主流流线向斜下方偏转,增强了整体换热强度且整体压力分布趋于均匀;轴宽比从0.3增加到0.7,气膜孔对整体流动和传热影响不大,轴宽比增加到0.9,主流小旋涡消失且靶面Nu分布更均匀;周向角度小于0°时,随着周向角度的增加,气膜孔上游高速区增大,周向角度超过0°后,高速区随周向角度增长不明显;随着周向角度增加,周向平均压力系数增加,气膜孔附近高Nu区扩大,靶面高Nu区分布更均匀。
[Abstract]:In order to study the effect of the geometric position of the film hole on the swirl cooling characteristics, the cooling structure of the swirl cavity with the film hole was established. The difference of the swirl cooling performance under the condition of the presence of the film hole was compared and analyzed by using the hydrodynamic software ANSYS CFX. The effects of the axial width ratio and the circumferential angle of the film hole on the swirl cooling flow and heat transfer characteristics are studied. The results show that the film hole has a strong disturbance to the swirl cooling air movement on the target surface of the swirl cavity, which makes the upstream air cooling velocity of the film hole increase. The flow velocity of the downstream cooling air decreases, the film hole deflects the main stream line below the syncline, enhances the overall heat transfer intensity and the overall pressure distribution tends to be uniform, the axial width ratio increases from 0.3 to 0.7, and the film hole has little effect on the overall flow and heat transfer. When the axial width ratio increases to 0.9, the main vortex disappears and the Nu distribution of the target surface becomes more uniform, and when the circumferential angle is less than 0 掳, the high speed zone increases with the increase of the circumferential angle, but when the circumferential angle exceeds 0 掳, the high speed region does not increase significantly with the circumferential angle. With the increase of the circumferential angle, the average circumferential pressure coefficient increases, the high Nu region near the film hole expands, and the high Nu area of the target surface is more evenly distributed.
【作者单位】：西安交通大学叶轮机械研究所;
【分类号】：TK471

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