Burning law determination using numerical simulation of propellants burning in the closed vessel

Abstract

This paper proposes a method of determining the “real” combustion law based on numerical simulation that also takes into account the thermal transfer between the hot gases resulting from deflagration and the walls of the vessel. This method is validated using the experimental results obtained in the closed vessel for SB propellant type, used in small-caliber propulsion systems. The proposed method is implemented using Ansys Fluent software, having as input the properties of the closed vessel walls from technical literature and of the gases resulting from the deflagration of propellant, calculated using a thermochemical model. To simulate the burning phenomena of the propellant charge and the impact that may occur between the propellants elements, on the one hand, and between the propellants element and the inner walls of the vessel, on the other hand, we used a dynamic mesh and mathematical models using UDF. For validation we used the diagrams from experimental tests made in the closed vessel at two different loading densities, the results obtained being in good agreement with the experimental ones. Moreover, the method used allows us to evaluate the error due to not taking into account the thermal losses that occurred in the closed vessel.