The Effect of Isentropic Exponent on Transonic Turbine Performance
The Effect of Isentropic Exponent on Transonic Turbine Performance
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DOI：
10.1115/1.4046528
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发表时间：
2020-08-01
影响因子：
1.7
通讯作者：
Wheeler, Andrew P. S.
中科院分区：
文献类型：
--
作者：
Baumgartner, David;Otter, John J.;Wheeler, Andrew P. S.
等熵指数是影响气体动力学的最重要性质之一。尽管如此，其对涡轮机性能的影响还不是很清楚。本文讨论了一系列的实验和计算研究，以确定等熵指数对涡轮机叶片内流场的影响。使用新修改的瞬态风洞进行实验，使环形叶栅测试与广泛的工作流体和操作条件。对于本研究中，使用空气，CO2，R134 a，和氩气进行测试，等熵指数的范围从1.08到1.67。测量结果包括详细的壁面静压，并与计算模拟进行比较。我们的结果表明，在这里测试的等熵指数范围内，损失可以在20%和35%之间变化，这取决于叶片出口马赫数。这些结果对于未来的涡轮机在真实气体效应和/或高气体温度可能导致等熵指数变化的情况下运行具有重要意义。
The isentropic exponent is one of the most important properties affecting gas dynamics. Nonetheless, its effect on turbine performance is not well known. This paper discusses a series of experimental and computational studies to determine the effect of isentropic exponent on the flow field within a turbine vane. Experiments are performed using a newly modified transient wind tunnel that enables annular cascade testing with a wide range of working fluids and operating conditions. For the present study, tests are undertaken using air, CO2, R134a, and argon, giving a range of isentropic exponent from 1.08 to 1.67. Measurements include detailed wall static pressures that are compared with computational simulations. Our results show that over the range of isentropic exponents tested here, the loss can vary between 20% and 35%, depending on vane exit Mach number. The results are important for future turbines operating with real-gas effects and/or those where high gas temperatures can lead to variations in the isentropic exponent.