A combined experimental and numerical investigation of premixed flame-wall interaction in turbulent boundary layers

壁面的存在改变了与湍流预混火焰相关的热化学和流体动力学过程。随着市场对燃烧室轻量化要求的不断提高，燃烧室的火焰壁相互作用（FWI）不可避免地会影响燃烧室的冷却负荷、热效率和污染物排放。然而，在现有的湍流反应流文献中，这方面还没有得到充分的分析，因为这对实验和数值研究在空间和时间分辨率等方面都构成了挑战。因此，深入了解FWI的物理机制对于开发和设计更节能、更环保的燃烧装置是必要的。在这个项目中，高性能计算和实验技术的最新进展将被用于分析和模拟湍流边界层（TBLs）中的预混FWI。所提出的分析将考虑湍流通道流动和无约束边界层（BLs）中不同的FWI配置（基于平均火焰法向相对于壁面的方向），使用最先进的实验和高保真度直接数值模拟不同的壁面边界条件。实验将利用一套先进的激光诊断，提供新的同步测量能力。DNS将模拟湍流，而不需要任何物理近似。从DNS和实验数据中获得的基本物理见解将用于开发用于FWI设备级模拟的新型混合RANS/LES方法，该方法基于Reynolds平均Navier Stokes （RANS）和大涡模拟（LES）的火焰表面密度（FSD）和标量耗散率（SDR）闭包的专业知识。新开发的模型将用于实验配置的混合RANS/LES，以进行模型验证。该项目将为节能和低排放燃烧装置（如燃气轮机、微型燃烧器和汽车发动机）提供强大且具有成本效益的计算流体动力学（CFD）设计工具。

The presence of walls alters the thermo-chemical and fluid-dynamical processes associated with turbulent premixed flames. The increasing demands for light-weight combustors make flame-wall interactions (FWI) inevitable, which influence the cooling load, thermal efficiency and pollutant emission in these applications. However, this aspect has not yet been sufficiently analysed in the existing turbulent reacting flow literature because of the challenge this poses for both experimental and numerical investigations in terms of spatial and temporal resolutions among others. Therefore, a thorough physical understanding of the FWI mechanism is necessary to develop and design more energy-efficient and environmentally-friendly combustion devices. In this project, recent advances of both high-performance computing and experimental techniques will be utilised to analyse and model premixed FWI in turbulent boundary layers (TBLs). The proposed analysis will consider different FWI configurations (based on the orientation of the mean flame normal with respect to the wall) in turbulent channel flows and unconfined boundary layers (BLs) using state-of-the-art experiments and high-fidelity Direct Numerical Simulations for different wall boundary conditions. Experiments will utilize a suite of advanced laser diagnostics, providing new simultaneous measurement capabilities. DNS will simulate the turbulent flow without any recourse to physical approximations. The fundamental physical insights obtained from DNS and experimental data will be used to develop a novel hybrid RANS/LES approach for device-scale simulation of FWI, building on expertise in the context of Flame Surface Density (FSD) and Scalar Dissipation Rate (SDR) closures for Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulations (LES). The newly-developed models will be implemented to carry out hybrid RANS/LES of experimental configurations for the purpose of model validation. The project will offer robust and cost-effective Computational Fluid Dynamics (CFD) design tools for fuel-efficient and low-emission combustion devices (e.g. gas turbines, micro-combustors and automotive engines).