Investigation of Turbulence Models for Multi-stage Launch Vehicle Analysis Including Base Flow

Publisher Summary Accurate flight analysis of launch vehicle is one of the major topics in aeronautic and astronautic engineering. However, many numerical researches failed to give reliable result because of much simplification of the present problem. However, current research adopted their definition of turbulent viscosity only, leaving stress-strain relationship linear. It is presumed that the authors' simplification to Craft-Launder-Suga model caused this inaccuracy of the solution. But, original Craft-Launder-Suga model requires much more computation time if cubic stress-strain relation is implemented. Most of the normal force of booster is induced by the oblique shock from the skirt and the expansion wave from the base plane of core rocket. In viscous analysis, the propagation range of the shock is less than the inviscid case. Various turbulence models are implemented on a flow solver and the most suitable turbulence model for launch vehicle simulation is investigated. A relatively lower pitching moment in turbulent analysis implies that booster may show unsafe movement during separation than inviscid simulation.