| Zusammenfassung |
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). |
