Simulation Research On Heat Flux Distribution Of Aero-engine Fire Protection Test

The fire protection test of aero-engine, which is a vital process of airworthiness certification for aero-engine, is a fundamental test. Since there is a lack of actual data of the fire protection test of aero-engine in our country, the research on the fire protection test of aero-engine is developed. In this way, the heat flux distribution will be obtained by numerical simulation technique which can offer help for the airworthiness certification of fire protection. In this paper, the heat flux distribution will be obtained by numerical simulation technique. The simulation process coupled combustion kinetic model provides the species concentration distribution of combustion medium. There are the main research contents.(1) A new method of mechanism reduction, named COMREFT method, is developed by analyzing the existing method, in which the advantages of the computational singular perturbation method and direct relation graph method are combined. The reciprocals of the diagonal elements are the time scales, which can identify the steady-state species. And the non-diagonal elements will be used to analyze the coupling relationship between other species and steady-state species.(2) A reduced mechanism of Jet A which used in the fire protection test of aero-engine, consists of 84 species and 261 reactions, develops from COMREFT method that is found to mimic the performance of the detailed mechanism with high fidelity under fire protection test condition. And a combustion kinetic model named JA-COMREFT model is obtained which consists of thermodynamic data, reaction parameters and the reduced mechanism. The JA-COMREFT model can be used in the simulation of combustion field of the fire protection test.(3) The simulation of combustion field of the fire protection test is made through coupling with the JA-COMREFT model. And the temperature distribution and species distribution can be computed by which the radiation characteristics parameters will be get. Not until the means exerted, can results solve the heat flux distribution. The geographical distribution range of the heat flux is obtained by the analysis of the results. There is a zone in which the heat flux is well distributed and gets the minimal value, which can assess the state of flame of test.