Experimental investigation of the interaction between swirl stabilized pressurized flames and effusion cooled walls related to thermochemical states, reaction rates and pollutant formation

本项目的目的是实验研究与航空发动机相关的贫油湍流旋流火焰与燃烧室壁面泻流冷却之间的相互作用。研究的重点是泻流冷却对局部热化学状态，反应速率和一氧化碳作为重要污染物物种的主要形成的影响。对航空发动机的需求正在增加，这是ACARE 2020或Flightpath 2050协议目标的结果。这些要求迫使用稀薄燃烧概念取代富-淬-稀燃烧，因为它们有可能大大减少氮氧化物的形成。作为缺点，可用的冷却空气的量减少，并且反应区被移动得更靠近燃烧器壁。因此，壁处的热负荷强烈地增加，这由于需要提高燃料消耗的较高压力比而通过较高的冷却空气温度而被额外地强化。冷却空气流不仅对热管理非常重要，而且还影响燃烧化学。而有效的冷却概念已被广泛研究，在过去，冷却气流对当地的热化学状态，反应速率和污染物的形成几乎没有调查，虽然这些问题是高度相关的，以满足未来的环境目标。该项目旨在关注这些具有挑战性的问题。为此目的，激光诊断应用于加压燃烧室，其中模仿燃气涡轮机燃烧的重要特征。实验结果将有助于更好地了解相互关联的物理和化学过程，独特的实验数据将支持验证数值燃烧模型。

The objective of this project is to experimentally investigate the interaction between lean turbulent swirling flames being relevant for aero engines and effusion cooling of combustor walls. The research focus is on the impact of effusion cooling upon local thermochemical states, reaction rates and primary formation of carbon monoxide as important pollutant species. Demands for aero engines are increasing, and result from the agreement targets of ACARE2020 or the Flightpath 2050. These demands enforce a replacement of rich-quench-lean combustion by lean combustion concepts, due to their potential for much decreased formation of nitric oxides. As a drawback, the amount of available cooling air decreases and reaction zones are shifted closer to the combustor walls. As a consequence, the thermal load at the walls is strongly increased which is intensified additionally by higher cooling air temperatures due to higher pressure ratios as needed to improve fuel consumption. Cooling air streams are not only highly important for the thermal management, but influence as well combustion chemistry. Whereas efficient cooling concepts have been investigated broadly in the past, the impact of cooling air flows upon local thermochemical states, reaction rates and pollutant formation has hardly been investigated although these issues are highly relevant for meeting future environmental targets. This project aims to focus on these challenging issues. For this purpose laser diagnostics are applied to a pressurized combustor where important features of gas turbine combustion are mimicked. Experimental results will serve for an improved understanding of the interlinked physical and chemical processes and unique experimental data will support validation of numerical combustion modelling.