Performance Study of a Gas Cannon with a Laval Nozzle Based on CFD Analysis

Based on the ideal gas-cannon theory (IGT), analysis and study of the motion characteristics of the one-stage gas cannon projectile when subjected to high-pressure gas impact has been performed. The computational fluid dynamics (CFD) software STAR-CCM+ is used to study the relevance between projectile motion characteristics and initial chamber pressure under the premise of mesh convergence verification. By comparing with the theoretical calculation results, the simulation results are within 85% to 90% of the IGT theoretical calculation results, therefore, the combined IGT-CFD method is considered feasible. The results show that the dependence of the projectile exit kinetic energy on the initial pressure decreases with increasing pressure. In addition, compared with the conventional equal-section cylindrical tube, the kinetic energy of projectile discharge can be increased by adding a Laval nozzle design to the high-pressure chamber and gas cannon barrel section. Therefore, the use of a Laval nozzle structure can increase the utilization of high-pressure gas, which is more meaningful in engineering applications.