A New Method to Investigate Unsteady Heat Transfer in a Turbine Research Rig

实验传热学最困难的领域之一是确定放置在内部的固体表面的热响应。流动到高度非稳定的温度波动，压力、速度等。近年来，已经开发出能够分析这种流动的非常复杂的计算机代码，但是通常，它们涉及到一些半经验主义。因此，对这些非稳态代码进行实验验证是非常重要的。然而，实验技术的进步并没有跟上这种计算发展的步伐，需要做大量的工作来提供这种验证。非定常效应非常重要的一个领域是涡轮机械领域，在该领域中，转子-定子流动相互作用、激波产生、湍流、叶片-边界层相互作用等产生了高度非定常。宾夕法尼亚州立大学的轴流涡轮设备及其在转子参照系中的仪器是尝试这种验证的唯一设备。所提出的研究的创新之处在于试图通过在涡轮机械外围相对较小的部分引入高温气流来模拟涡轮机械中的非稳态换热，在一个非常小的时间增量上。如果仿真证明是有效的，那么将大大简化透平机械非定常传递特性的实验研究，并导致在这一重要领域取得较快进展。此外，本研究还将提供有关非稳态换热的基本信息。

One of the most difficult areas of experimental heat transfer is that of determining the thermal response of solid surfaces placed inside the flow to highly non-steady fluctuations in temperature, pressure, velocity, etc. In recent years, very sophisticated computer codes have been developed which are capable of analyzing such flows, but typically, they involve some semi-empiricism. Experimental validation of these non- steady codes is therefore of great importance. However, the progress of experimental techniques has not kept pace with such computational developments, and much work is needed to provide such validation. One area where non-steady effects are of great importance is the area of turbo-machinery where high non-steadiness is produced by rotor-stator flow interactions, shock wave generation, turbulence, blade-boundary layer interaction, and the like. The Axial Flow Turbine Facility at Penn State with its instrumentation in the rotor frame of reference is uniquely equipped to attempt such validation. The innovation of the proposed research is to attempt to simulate non-steady heat transfer in a turbo-machine by introducing a slug of high temperature air flow at a relatively small segment of the periphery of the turbo- machine, over a very small increment of time. If the simulation proves valid, then the experimental study of non-steady transfer characteristics in turbo-machines will be greatly simplified, and lead to relatively rapid progress in this important field. In addition, fundamental information on non-steady heat transfer will emerge from this study.