Application Of Compressible FPV Model In Supersonic Turbulent Combustion

The scramjet engine is an important propulsion device for achieving hypersonic flight.In recent years,scramjet have received extensive attention from researchers due to simple structure and high load rate.With the raseing of new theories and models,and the development of computer hardware conditions,numerical simulation has become an important means of studying scramjet.In this paper,with the numerical simulation method,the flamelet model is used to research the flow,heat transfer and combustion problems in the scramjet.Based on the summary of the research in recent years,it is found that the compressible flamelet/progress variable model fails when predicting the temperature peaks and combustion intermediate components under high pressure conditions.Based on the OpenFOAM,the CFPV model is obtained by pressure correction on FPV model,and it is used in the research of scrambling problem.The effect of turbulent scalar transport in supersonic combustion is important.In this paper,the flow field is affected by the turbulent Schmidt number and the turbulent Prandtl number.The results show that the turbulent Schmidt number has an effect on the flame length and width.When the value is 0.7,it matches the experimental value.The turbulent Prandtl number has an effect on the temperature of the reaction,but it is found that the global turbulent Prandtl number of the constant value is difficult to reflect the different positions of the flow field.In order to investigate the application of CFPV,the DLR struct and cavity were computed.Comparing the simulated values with the experimental values,it is found that the prediction accuracy of the CFPV model is higher than that of the original compressible FPV model in temperature and time average speed.The CFPV model is used to investigate the flow field characteristics in the cavity.It is found that the complex shock wave system formed behind the fuel is sprayed helps the ignition to occur;the low velocity recirculation zone is generated in the cavity,which enhance the fuel blending.It is also found that the fuel condensed and burned stably in the cavity and the cavity shear layer.In order to verify the applicability of the CFPV model to supersonic combustion further,the CFPV model was used to research the Gamma combustion chamber.It is found that the fuel was sprayed to form a barrel shock wave,a bow shock,a shock wave and a Mach disk.Similar conclusions were obtained from the results of the literature simulation,but there is still a gap between the pressure and the prediction of OH.