Numerical simulation on unsteady dynamic boundary internal flow field of a nozzleless booster

The nozzleless booster makes use of grain expanded area to realize acceleration of gas flow, linear increase of burning area and exponent increase of the throat area, which can make internal flow field present obvious non-stationarity. Erosive combustion, non-uniform pressure distribution and grain deformation make the working process of nozzleless booster very complex. Through secondary development for FLUENT software, the numerical model of unsteady dynamic boundary internal flow field was derived. Ignition process and erosive combustion were taken into consideration to obtain burning area position and internal flow field distribution at different times, so that internal ballistic properties of the propellant can be predicted accurately. Working process of a nozzleless booster was simulated. The internal ballistic calculation curve agreed well with experimental curve.