Interaction of hydrogen flames and smart effusion-cooled gas turbine combustor walls

该项目的目的是研究未来氢动力燃气轮机自适应喷雾冷却的科学基础。研究概念包括热流体和材料科学问题，并将其联系起来。在氢气燃烧中，由于火焰熄灭距离比传统燃料小得多，火焰与燃烧室壁面的相互作用非常强烈。这导致了更高的壁面热流，并需要适应氢气操作的冷却。由于其冷却效率高，冷却质量流量要求相对较低，因此适合用来冷却。在该项目中，将采用添加制造(AM)工艺生产带有集成传感器和致动器的功能化智能墙结构，并研究其与贫氢火焰的相互作用和稳定性。温度传感器将集成到墙体中，以确定不同火焰与墙体相互作用场景下的墙体热负荷。AM制造的多孔壁结构将被用来产生均匀的冷却膜。作为一个有远见的概念，高温形状记忆合金将与伸展结构相结合，作为执行器，作为氢燃烧引起的壁热负荷(传感器)的函数，自适应(智能)控制冷却空气质量流量。这些复杂的壁面结构将在实验室实验中利用现代激光测量技术来表征冷却效率以及氢火焰、冷却气流和壁面之间的相互作用。一个重点是研究近壁火焰的结构，以及它是否像远离墙壁的火焰那样受到热扩散和流体动力不稳定性的显著影响。这些实验数据将被用来验证创新的数学燃烧模型，该模型考虑了近壁稀氢燃烧的细节。该项目开发的数值模拟工具的预测质量将针对不同的壁面冷却概念进行评估。因此，该项目对预测工程方法做出了重大贡献，而预测工程方法对于快速部署氢燃料燃气轮机至关重要。

The aim of this project is to research the scientific fundamentals of self-adapting effusion cooling for future hydrogen-powered gas turbines. The research concept encompasses and interlinks thermofluidic and materials science issues. In hydrogen combustion, there is a very intensive interaction of the flame with the combustion chamber wall due to significantly smaller flame quenching distances compared to conventional fuels. This results in higher wall heat fluxes and the need for adapted cooling for hydrogen operation. Effusion cooling is suitable because of its high efficiency and relatively low cooling mass flow requirement. In this project, functionalized smart wall structures with integrated sensors and actuators for effusion cooling will be produced using additive manufacturing (AM) processes and their interaction and stability with lean hydrogen flames will be investigated. Temperature sensors will be integrated into the wall to determine wall heat loads for different flame-wall interaction scenarios. AM fabricated porous wall structures will be used to generate a uniform cooling film. As a visionary concept, high-temperature shape memory alloys will be explored in combination with auxetic structures as actuators for self-adapting (smart) control of the cooling air mass flow as a function of the wall heat load (sensor) due to hydrogen combustion. These complex wall structures will be characterized in laboratory experiments with regard to cooling efficiency and interaction between hydrogen flame, cooling air flow and wall using modern laser measurement technology. One focus is on the investigation of the near-wall flame structure and whether it is significantly influenced by thermodiffusive and hydrodynamic instabilities as in flames far from walls. These experimental data will be used to validate innovative mathematical combustion models that take into account the specifics of near-wall lean hydrogen combustion. The prediction quality of the numerical simulation tools developed in the project will be evaluated for the different wall cooling concepts. Thus, the project contributes significantly to the predictive engineering approach, which is essential for the rapid deployment of hydrogen-fueled gas turbines.