A Gridless Method for Computing Interior Ballistic Flows With Moving Discrete Points

Abstract

This study presents a meshless computational framework for simulating unsteady fluid dynamics in interior ballistic applications. The proposed meshless method eliminates the need for grid generation and deformation by utilizing a cloud of dynamically moving points, based on the Arbitrary Lagrangian–Eulerian (ALE) formulation. The key novelty of this work is integrating the meshless solver with a moving points system, which makes it highly suitable for ballistics applications involving complex geometries. Furthermore, the combustion process has been simplified, streamlining the simulation by avoiding the need for fully modeling propellant combustion, as required in multiphase solvers. The framework discretizes the unsteady axisymmetric Euler equations using local weighted least-squares approximations to calculate derivatives. Numerical fluxes are computed using a modified Harten, Lax, van Leer, Contact (HLLC) scheme, which is essential for achieving high accuracy and effectively capturing complex flow features. Temporal evolution is handled using the Explicit Strong Stability Preserving (ESSP) Runge–Kutta method, ensuring stability and accuracy under unsteady flow conditions. The method is applied to interior ballistic simulations, such as the motion of an M107–155 mm shell launched through an M185 cannon, achieving excellent agreement with experimental observations, particularly in predicting muzzle velocity and peak pressure. The simplified setup of this framework enables it to handle large grid deformations and complex geometries, and makes it an efficient, high-fidelity solution for dynamic flow problems in ballistics and aerospace, serving as a reliable predictive and assessment tool for interior ballistics studies. Further, the pressure wave analysis conducted within this framework provides valuable insights for optimizing shell design and propellant combustion characteristics, while also enhancing its role as a predictive tool for assessing shell integrity and mitigating resonance-induced structural risks in interior ballistics applications.