Flow and heat transfer in complex film cooling configurations for application in future gas turbine combustors

复杂薄膜冷却配置中的流动和传热，适用于未来燃气轮机燃烧室

基本信息

批准号：
239213895
负责人：
Professor Dr. Michael Pfitzner
金额：
--
依托单位：
Institut für Thermodynamik (LRT-10)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/239213895?language=en
关键词：
Flow heat transfer complex film

项目摘要

Combustor cooling concepts for future gas turbine combustors must operate with a minimum amount of cooling air at maximum cooling efficiency. When using the low emission lean combustion technology, most of the air is required in the fuel injector, while at the same time the hot gas temperatures continue to rise in order to obtain maximum gas turbine process efficiency. When using effusion cooling, a liftoff of the cooling air jets and a reduction of the film cooling efficiency occurs especially at high blowing rates, which are typical of gas turbine combustion applications. In new cooling configurations like the trench cooling, where the cooling air from the effusion jet is distributed laterally, this lift-off effect is reduced considerably and can result in a considerably improved film cooling efficiency by one order of magnitude for some operating conditions.The goal of the proposed research project is to develop a deeper physical understanding of the detailed flow and heat transfer phenomena that occur in effusion cooling as compared to trench film cooling configurations by a combination of experimental and numerical investigations. The emphasis will be on the investigation of the complex unsteady flow, mixing and heat transfer processes in trench cooling configurations, which are not well understood. Using the generated results, optimized film cooling devices can be developed which feature a uniform and (for a large range of operating conditions) robust cooling film at minimal use of cooling air.The experimental research will use optical non-intrusive measurement technology (PIV - PIV, infrared temperature measurements, temperature-sensitive colors - TSP), supplemented by hot-wire and thermocouple measurements. Through use of high-speed PIV, the complex unsteady flow structures can be examined in great detail. A novel combination of infrared and TSP measurement techniques for measuring wall heat flows allows the determination of the local distribution of the heat transfer coefficient.The CFD simulations accompanying the experiment are performed using a commercial CFD code (FLUENT with realizable k-epsilon model). For the detailed numerical studies of the large scale unsteady flow structures, large eddy simulations will be performed using the open source CFD code OpenFOAM, which is already well established at the institute.

未来燃气轮机燃烧器的燃烧器冷却概念必须以最少量的冷却空气以最大的冷却效率运行。当采用低排放稀薄燃烧技术时，喷油器中需要大部分空气，同时热气温度不断升高，以获得最大的燃气轮机过程效率。当使用喷射冷却时，特别是在高吹风率的情况下，会发生冷却空气射流的升空和薄膜冷却效率的降低，这是燃气轮机燃烧应用的典型情况。在新的冷却配置中，例如沟槽冷却，来自喷射射流的冷却空气横向分布，这种提离效应大大减少，并且可以在某些操作条件下将薄膜冷却效率显着提高一个数量级。拟议研究项目的目标是通过实验和数值研究相结合，与沟槽薄膜冷却配置相比，对喷射冷却中发生的详细流动和传热现象有更深入的物理理解。重点将放在对沟槽冷却配置中复杂的非定常流动、混合和传热过程的研究上，这些过程尚不清楚。利用生成的结果，可以开发出优化的薄膜冷却装置，该装置具有均匀且（对于大范围的操作条件）坚固的冷却薄膜，并且使用最少的冷却空气。实验研究将使用光学非侵入式测量技术（PIV - PIV、红外温度测量、温度敏感颜色 - TSP），并辅以热线和热电偶测量。通过使用高速 PIV，可以详细检查复杂的非定常流动结构。用于测量壁热流的红外和 TSP 测量技术的新颖组合可以确定传热系数的局部分布。实验附带的 CFD 模拟使用商业 CFD 代码（具有可实现的 k-epsilon 模型的 FLUENT）进行。为了对大规模非定常流结构进行详细的数值研究，将使用该研究所已经成熟的开源 CFD 代码 OpenFOAM 进行大涡模拟。