A new experimental pressure-apparent burning rate model was established based on the recorded pressure-time data in the closed vessel to study the actual burning gas generate rate of a propellant whose form function is not available. The new burning model can replace the Vieille's law and form function of propellants in the interior ballistic equations to predict the interior ballistic performance of gun. As distinct from the traditional geometric form function based burning rate model, the new model introduced the concept of relative pressure impulse related to the actual burnt web thickness of propellant statistically. The apparent burning rate was expressed by the propellant mass fraction burnt vs. relative pressure impulse curve. Based on the recorded experimental pressure time data of three kinds of propellants, such as 12/1, 13/7 and 13/19 single-base propellants, numerical calculation was carried out using the computer program of the new model. And numerical calculation results were different form those of the traditional geometric form function based burning rate model. The new experimental pressure-apparent burning rate model is more suitable for the actual combustion circumstances of propellants in the closed vessel, for which is ultimate independent of the various grain sizes and have taken account of the influence of chamber pressure on the actual burning rate. The interior ballistic simulation of selected gun propellants was conducted using the new burning rate model. The results predicted by the new model show a good agreement with the classic interior ballistic predication results though the agreement with the experimental results is still to be improved.
propellant, closed vessel, burning rate models, interior ballistic, simulation