Ramjet Combustion Chamber Numerical Simulation Of The Work Process

In this paper, the turbulent combustion model of the Assisted Range Rocket Ramjet Engine secondary firebox is founded. The research about the process of the mixing and chemistry reactions of the secondary firebox two-dimension flow field has been done. The FLUENT software is used to simulate the design parameters' influence such as exit-pressure, mass-rate ratio of the air and fuel and the fuel's injecting angle on the mixing and combustion efficiency. The results indicate that when the fuel is pure gas, the flow field in the secondary firebox is very complex, including three vortexes, which are very important to the process of mixture and combustion. The pressure in the secondary firebox is even, but the temperature changes frequently. Increasing the exit- pressure and the mass-rate ratio, the temperature in front of the secondary firebox increases, the length of the secondary firebox when the fuel is burnt out decreases, the combustion efficiency increases. Increasing the fuel's injecting angle in some range, the radial velocity of the fuel increases, the axial velocity decreases, the fuel's remain-time in the secondary firebox increases, but it has little influence on the combustion efficiency. When the airspace varies, increasing the flying height, the temperature in front of the secondary firebox decreases the length of the secondary firebox when the fuel is burnt out increases, the combustion efficiency decreases. When the fuel includes gas and solid, the variation trend of the velocity vector, pressure, temperature and the mass fraction of each specie are the same as the pure gas's. If the diameter of the solid particles increases, the combustion efficiency decreases. If the length of the secondary firebox increases, the solid particles' remain-time evidently increases, the combustion efficiency increases in some range.