Effect of cooling hole configurations on combustion and heat transfer in an aero-engine combustor

Highlights: • The combustion and cooling performance of an aero-engine combustor is studied. • Four types of holes are introduced to reduce the thermal load of TBCs in combustor. • Fan-shaped holes result in the highest peak gas temperature and NOx emission. • The cooling effectiveness of console hole is the highest. A numerical model is developed to investigate the combustion and cooling performance of an aero-engine combustor. Cylindrical holes, conical holes, fan-shaped holes and console holes are introduced to reduce the thermal load of thermal barrier coatings (TBCs) in combustor, respectively. To reduce the coolant consumption, the number of film cooling holes in the first and second row at outer liner is decreased by 20% for comparison. The adoption of the four types holes leads to following results: the peak gas temperature increases from 2459.36 K to 2473.39 K, 2485.76 K, 2491.15 K, and 2464.57 K; the NO_x emission increases from 3.2306 g/kg to 3.4762 g/kg, 3.5197 g/kg, 3.5341 g/kg and 3.3494 g/kg; the peak working temperature of TBCs decreases by 149.01 K, 208.12 K, 248.64 K and 257.78 K respectively. Fan-shaped holes have the highest coolant discharge coefficient and correspond to the highest peak gas temperature and NO_x emission. The decrease of cooling hole number has very slight effect on TBCs peak working temperature, while it will reduce the peak gas temperature and the NO_x emission in the meanwhile. The cooling effectiveness of the console hole is the highest followed by the fan-shaped hole and the conical hole.