Second Vane Total Pressure Loss Due to Endwall Iceform Contouring
Second Vane Total Pressure Loss Due to Endwall Iceform Contouring
复制标题
由于端壁冰形轮廓导致的第二叶片总压力损失
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. S. Lafleur
中科院分区：
文献类型：
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作者：
R. S. Lafleur
冰成设计方法产生端壁轮廓，改变二次流，从而提高端壁传热负荷和总压损失。冰形成是类似于金属熔化的区域，其中热流体改变了零件的等温表面形状，因为它是由冷却流体保持的。在流动和热边界条件的约束下，通道流动、传热和几何形状共同演化。冰形成的概念不依赖于介质，可以用于类似的流动和材料来进化新的边界形状。在过去，这种方法已经被证明可以减少流动中的气动阻力和总压损失，例如扩散器和气缸/端壁交界处。先前的一篇论文[1]表明，在能效发动机（E3）中，雷诺数匹配的冰形几何比旋转对称的端壁几何低24%的平均端壁换热。比较了三种端壁几何形状：“冰形”、“E3”和“平面”作为端壁设计空间的极限情况。本文通过对端壁气动性能的报道，增加了结冰设计的记录。第二个叶片出口流速和压力使用直径为1.2 mm的五孔探针的自动二维横向测量。给出了三种端壁几何形状的出口平面图，显示了总压系数等高线和速度矢量的详细信息。二次流涡的形成表现在出口平面上，这对出口平面的总压损失分布产生了影响，导致出口流动的非设计过弯和下弯。出口平面轮廓被整合起来，形成总压力损失的总体度量。相对于E3端壁，冰形端壁的总压损失略大，这是由于通道内二次流的耗散较大。冰形端壁比E3端壁具有更接近设计的出口流型。ASME版权所有©2008
The iceformation design method generates an endwall contour, altering the secondary flows that produce elevated endwall heat transfer load and total pressure losses. Iceformation is an analog to regions of metal melting where a hot fluid alters the isothermal surface shape of a part as it is maintained by a cooling fluid. The passage flow, heat transfer and geometry evolve together under the constraints of flow and thermal boundary conditions. The iceformation concept is not media dependent and can be used in analogous flows and materials to evolve novel boundary shapes. In the past, this method has been shown to reduce aerodynamic drag and total pressure loss in flows such as diffusers and cylinder/endwall junctures. A prior paper [1] showed that the Reynolds number matched iceform geometry had a 24% lower average endwall heat transfer than the rotationally symmetric endwall geometry of the Energy Efficiency Engine (E3). Comparisons were made between three endwall geometries: the ‘iceform’, the ‘E3’ and the ‘flat’ as a limiting case of the endwall design space. This paper adds to the iceformation design record by reporting the endwall aerodynamic performances. Second vane exit flow velocities and pressures were measured using an automated 2-D traverse of a 1.2 mm diameter five-hole probe. Exit plane maps for the three endwall geometries are presented showing the details of the total pressure coefficient contours and the velocity vectors. The formation of secondary flow vortices is shown in the exit plane and this results in an impact on exit plane total pressure loss distribution, off-design over- and under-turning of the exit flow. The exit plane contours are integrated to form overall measures of the total pressure loss. Relative to the E3 endwall, the iceform endwall has a slightly higher total pressure loss attributed to higher dissipation of the secondary flow within the passage. The iceform endwall has a closer-to-design exit flow pattern than the E3 endwall.Copyright © 2008 by ASME