Aerothermal analysis of film cooling flow structures

固定式燃气轮机和航空发动机仍然是未来能源和运输部门的关键技术。为了进一步提高热效率，必须实现更高的总压比和涡轮机入口温度。因此，更好的冷却方法是绝对必要的。特别是在第一高压涡轮机级中，薄膜冷却是必不可少的。为了能够充分描述冷却孔入口处和冷却孔中的冷却空气流，以及喷射的冷却空气与热气体之间的相互作用，除了文献中已经广泛的热测量之外，特别需要速度场测量。为了量化传统气膜冷却孔几何形状的气膜冷却流在不同操作条件下的气动特性，将使用红外热成像和立体粒子图像测速仪在现有的试验台上进行测量，在拟议的项目。除了经典的评估方法外，数据驱动的方法特别适合于随后的流量表征。例如，它们可用于识别相干结构并分析其时间行为。此外，在该项目中收集的数据，特别是速度场，绝热薄膜冷却效率和传热系数，有和没有薄膜冷却，将不仅用于验证数值流模拟，但也改善数值方法和模型。

Stationary gas turbines and aero engines continue to be a key technology for the energy and transport sector of the future. To further enhance thermal efficiency, higher total pressure ratios and turbine entry temperatures must be realised. Therefore, better cooling methods are absolutely necessary. Especially in the first high pressure turbine stages, film cooling is essential. In order to be able to fully describe the cooling air flow at the cooling hole inlet and in the cooling hole, as well as the interaction between the ejected cooling air and the hot gas, velocity field measurements in particular are necessary in addition to the already extensive thermal measurements available in literature. In order to quantify the aerothermal behaviour of the film cooling flows of conventional film cooling hole geometries under different operating conditions, measurements using infrared thermography and stereoscopic particle image velocimetry are to be carried out on an existing test rig in the proposed project. In addition to classical evaluation methods, data-driven methods are particularly suitable for the subsequent characterisation of the flow. They can be used, for example, to identify coherent structures and analyse their temporal behaviour. In addition, the data collected in the project, in particular the velocity fields, the adiabatic film cooling effectiveness and the heat transfer coefficients with and without film cooling, will serve not only to validate numerical flow simulations but also to improve numerical methods and models.