A chamber pressure simulator with an exhaust element

In order to achieve the time-history curves of chamber pressure conveniently and efficiently at the lab-scale and further to investigate the damage patterns of typical structures and materials during transient high pressure in the chamber, a chamber pressure simulator with an exhaust element to discharge the gas generated due to the propellant combustion in the vessel was developed. A mathematical model which describes the working principle of the simulator was derived according to the propellant combustion theory and the isentropic flow model. The mass flow rate during the depressurization procedure was attained using the software Fluent on the basis of the ideal gas hypothesis, which was compared to theoretical results to determine the discharge coefficient. The performance parameters of the simulator were designed optimally based on the characteristics of time-history curves of chamber pressure for 76 mm and 155 mm guns and the miniaturization design principle. Optimization results show that pressurization and depressurization rates are satisfactory, the peak pressure is about 300 MPa and the duration when the pressure is higher than 30 MPa is longer than 10 ms. Results of verification tests present good repeatability and are coincident with theoretical results, which indicates that the simulator works with high reliability. It is feasible to simulate time-history curves of chamber pressure through exhausting propellant gas directly.