Numerical Study On Auto-ignition Of Kerosene Jet

Liquid fuel combustion, including many complex physical and chemical mechanisms such as the atomization, vaporization, mixing and chemical reactions, has been widely used in the power systems. Numerical simulations of turbulent two-phase spray combustion is an important method to take into account in a coupled way all underlying complex physical and chemical phenomena, and to obtain the detailed turbulent flow field and scalar field to support the engineering design of higher performance engines.The present research concentrated on the numerical simulation of auto-ignition process of the liquid fuel injected into the high temperature and high velocity air co-flow. Typically, autoignition process involves physical delay and chemical delay. The work here focused on the first one aforementioned. The factors of jet angle, primary atomization and second break up models, turbulent mixing on the auto-ignition delay were carefully studied in a tested combustor. The research can be categorized into two parts:(1) Based on standard k -εturbulence model, simulations of the unsteady process of flow past square cylinder both in rough and exactitude grids with PRNS (Partially Resolved Numerical Simulation) and DES (Detached Eddy Simulation) combined in the RANS/LES method were performed. Results showed that the RANS/LES method even in the rough gird outperform the standard k -εmodel. Due to its lower computations costs and higher performances, RANS/LES method may be developed to the turbulent combustion.(2) The Euler-Lagrangian method was used to simulate auto-ignition process of the liquid fuel injected into the high temperature and high velocity air co-flow. Detailed information about the radius of curvature of the inlet corner, the state of the Nozzle,Spray Breakup Models,nozzle pressure's affection on the ignition delay was obtained.