Numerical Simulation On Formation Process Of Flammable Mixture In Aero-Engine Combustor

Aero-engine combustor's design must solve lots of problems, such as exit temperature field quality, nozzle vibration, NOx forming etc. A key influence on solving these problems is the forming process of flammable mixture gas in the aero-engine combustor. It determines the combustion stability, combustion efficiency, the temperature field quality, pollutants emitting etc. In order to satisfy the need of improving combustion quality in aero-engine combustor, increasing the oil fuel evaporation velocity and gas fuel concentration in the flammable mixture gas, this thesis refers to others'oil fuel evaporation experiments of the fuel's spray, and adopted oil fuel evaporation and heat release physics-mathematics model, simulated the flow field, temperature field and fuel-gas's concentration field of combustible mixture's formation course by using CFD software and UDF procedure. The numerical simulation results are better accord with the physical experimental.This thesis comparatively researched the transfer low of fluid flow, mixing, heat transfer and atomized oil fuel's physical evaporation and chemical evaporation in the hot inert gas and air respectively within the areas of head mixed, near wall's circum lay, and full development. The mixing and heat transfer characteristics of three evaporating phases that of heated beginning, heated evaporating transition and evaporation have been comparatively analyzed. The results of numerical simulation are identical with the physical experimental results. By using atomized oil evaporating and heat releasing models of the atomized fuel's cool flame reaction in the hot air, the laws and mechanism have been revealed in depth. The influencing factors that of flammable mixture gas forming process have been deeply studied. Increasing inlet air temperature and fuel/air ratio properly, both of oil fuel atomized velocity and gas fuel concentration can all be enhanced, and evaporation region enlarged. The best suitable pipe's length is studied by numerical calculation.This paper thoroughly investigated the formatting rules of flammable mixture gas. The study conclusions will be the important basis for aero-engine combustor's design.