Numerical Simulation Of Multi-hole Cooling Scheme For Combustor Liner

Highly efficient cooling methods are desperately needed to make better use of the cooling air which is reduced by the tendency of higher temperature rise and less pollution in aero engine. Inclined multi-hole full-coverage film cooling, as a practical cooling scheme, has received widespread attention. The paper reports on numerical study of the flow and heat transfer characteristics of multi-perforated plates.The heat transfer characteristics inside film cooling holes are investigated numerically. The results show that inclination angle of a film cooling hole has significant influence on local convection coefficient distribution which can be explained by the theory of enhanced heat transfer and analyzing synergetic relation of relevant fields.The effects of inclination angles and blowing ratios on the cooling efficiency and discharge coefficient are studied by numerical simulation using a simplified multiperforated plate model and the results are also proved by the theory of field synergism. Besides that, 5 optimized structures are compared with the traditional structure. The study shows that a combined use of different inclination angels of cooling holes, the un-uniform holes arrangement, the multi-perforated plate with an upstream baffle can increase cooling effectiveness at front regions. The use of elliptic holes helps to enhance attachment of jets and trenched cooling holes benefits jets' lateral diffusion. In a word, the optimized structures receive better cooling effects.A combustor liner model is established to investigate the influence of structural parameters including inclination angle, deflection angle, swirl angle, the shape of cooling holes and un-uniform hole array on the flow field and temperature field in the combustion chamber.