Pressure Drop Characteristics Of Hydrocarbon Fuel Flowing Inside The Regenerative Cooling Channels Of Scramjet

In this paper,based on experimental method and numerical simulation,the pressure drop characteristics of hydrocarbon fuel flowing inside the regenerative cooling channels of scramjet have been studied.The research focuses on the pressure drop characteristics of n-decane under sub-critical and supercritical pressure.Based on the experimental data,a new pressure drop correlation was put forward.The gas phase volume fraction and pressure drop distributions of the two-phase n-decane in the tube are obtained by using a two-dimensional axisymmetric model.Effects of parameter of operating condition on pressure drop characteristics of n-decane were investigated,the pressure drop increases with mass flux and heat flux,and decreases with the increasing pressure and diameter.By comparing the simulation data and two-phase correlation in the literature,the results indicate that the Licheng Sun modified model has the most high accuracy.The pressure drop characteristics of n-decane under sub-critical pressure were tested and researched.Under sub-critical pressure,n-decane could be divided into three regimes,namely,pure liquid phase,pure gas phase and two-phase.In the pure liquid regime,when the fluid is in a laminar flow pressure drop increases with fluid temperature,when the fluid is in a turbulent flow,pressure drop has nothing to do with fluid temperature.In pure gas regime,pressure drop increases with fluid temperture.In two-phase regime,pressure drop is increased at first and then decreased with dryness fraction.Furthermore,effects of pressure and mass flux on the pressure drop characteristics of n-decane under sub-critical pressure were investigated.Pressure drop increases with mass flux.The pressure drop of liuqid phase has nothing to do with pressure,the pressure drop of gas phase and two-phase decreases with the increasing pressure.The pressure drop characteristics of n-decane under supercritical pressure were tested and researched.Under supercritical pressure,n-decane could be divided into two regimes,namely,compressible fluid and suprecritical fluid.Pressure drop characteristics of compressible fluid is similar to that of liquid phase.The change in pressure drop of compressible fluid with fluid temperature,pressure and mass flux is similar to that of liquid phase.In addition to preesure,when other parameters remain the same,pressure drop of liquid phase is greater than that of compressible fluid.Pressure drop characteristics of supercritical fluid is similar to that of gas phase.The change in pressure drop of supercritical fluid with fluid temperature and mass flux is similar to that of gas phase.In gas regime,pressure and mass flux have nothing to do with the change in coefficient of friction and Re,but in superctitical fluid regime,that have an effect on the change in coefficient of friction and Re.Based on the experimental data,for the different flow regime under sub-critical and supercritical pressure,new pressure drop correlations were put forward respectively.New correlations get a better precision of pressure drop characteristics of this paper.