Study On The Silo Jet Flow Field During The Launching

In the launching silo, the rocket engine generates high temperature and pressureexhaust plume. So thermal shock and dynamic impacting are caused on the silofacility. In this paper, in order to provide necessary theoretical support forconstructing or defending the silo facility, the jet flow is studied.The rocket-silo model is built to study the effect on the silo environment duringthe launching. Because the silo is in a closed state and the flow-guide groove is on thebottom, jet flow is only discharged outward the groove. Some gas is gathered insidethe silo owing to failure to be discharged, so the temperature and pressure rise. In thelaunch, due to the narrow silo space, the high temperature and pressure jet closed tothe silo walls greatly affects the silo.1The jet flow field including species transport model was studies. The transportmodel without species and the species transport model were simulated to analyze theeffect on of the species transport model on the simulated results. The differences ofthe gas parameters, such as viscosity, density and specific heat, greatly affect the flowfield. So the species transport model should be applied to simulate such problem.2The effect on the silo environment was studied from different angles or atdifferent discrete schemes. The engine nozzle swings to adjust the rocket attitude inthe launching process. One condition is that the initial established angle between thejet flow and the axes was small enough to be ignored. And another is that the angle isset to10degrees. In the two operating conditions, the jet flow field was analyzed byusing first order upwind scheme, second order upwind scheme and QUICK scheme.The obvious differences appear at the jet flow in the two conditions. Due to thenarrow silo space and the closer distance between the jet flow and the silo walls, thedata of the testing points greatly change when the angle between the jet flow and axesappears smaller change. For the discrete format, the great calculation error is causedby using the first order upwind scheme owing to the numerical diffusion. The twodiscrete schemes always cause the numerical viscosity, but to reduce the numericalerror effectively. The results calculated by using second order upwind scheme is similar to that calculated by using QUICK scheme. However, QUICK scheme is moresuitable to the measuring points on the wellhead by the curvature correction.3The influence of different turbulence models on the flow field was researched.The difference of the results among different turbulence models and the reasoncausing the difference were analyzed. The results showed that different models doesnot affect flow pattern but to influence local flow intensity. Finally the more effectiveturbulence model is given for engineering.4The recrudescence affects the jet flow in the launching silo. The above twoconditions were simulated by applying recrudescence model. Compared with theresults without recrudescence model, the results with recrudescence model revealedthere is an obvious recrudescence in the early stage and then recrudescence isgenerally weakened with consuming the oxygen.5Finally, the experimental data was compared with the numerical one. Thereason causing the difference among them was analyzed and the simulation model hasbeen validated. The flowing form of the gas jet was estimated in detail in allexperiments.