Use of Pressure Measurements to Determine Effectiveness of Turbine Rim Seals
Use of Pressure Measurements to Determine Effectiveness of Turbine Rim Seals
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DOI：
10.1115/1.4028395
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发表时间：
2015-03-01
影响因子：
1.5
通讯作者：
Lock, Gary D.
中科院分区：
文献类型：
--
作者：
Owen, J. Michael;Wu, Kang;Lock, Gary D.
热气体通过燃气轮机轮缘密封圈的进入取决于涡轮环空主流流与轮缘密封圈径向向内轮空主流流之间的压差。在本文中，对先前发布的孔板模型进行了修改，以便通过钻机浓度测量确定的密封有效性epsilon(c)可以用于确定发动机压力测量确定的有效性epsilon(p)。假设在叶片平台上有一个假设的“最佳点”，在那里测量的压力将确保ep的计算值等于ec，即浓度测量确定的值。径向间隙密封的实验测量表明，正如预测的那样，假设的最佳点压差与在叶片平台上任意位置测量的压差呈线性相关。用理论模型测定的ep值与浓度测量测定的ec值之间有很好的一致性。使用3D稳态计算流体动力学（CFD）程序进行的辅助计算表明，甜点的轴向位置非常接近密封间隙的上游边缘。从理论上讲，从钻井平台的压力和浓度测量中获得的参数可以用来计算发动机的密封效果。
The ingress of hot gas through the rim seal of a gas turbine depends on the pressure difference between the mainstream flow in the turbine annulus and that in the wheel-space radially inward of the rim seal. In this paper, a previously published orifice model is modified so that the sealing effectiveness epsilon(c) determined from concentration measurements in a rig could be used to determine epsilon(p), the effectiveness determined from pressure measurements in an engine. It is assumed that there is a hypothetical "sweet spot" on the vane platform where the measured pressures would ensure that the calculated value of ep equals ec, the value determined from concentration measurements. Experimental measurements for a radial-clearance seal show that, as predicted, the hypothetical pressure difference at the sweet spot is linearly related to the pressure difference measured at an arbitrary location on the vane platform. There is good agreement between the values of ep determined using the theoretical model and values of ec determined from concentration measurements. Supporting computations, using a 3D steady computational fluid dynamics (CFD) code, show that the axial location of the sweet spot is very close to the upstream edge of the seal clearance. It is shown how parameters obtained from measurements of pressure and concentration in a rig could, in principle, be used to calculate the sealing effectiveness in an engine.