Abstract
The moving boundary truncated grid method is employed to solve the Boltzmann-BGK equation, with a focus on enhancing computational efficiency in physical kinetics. The truncated grid method allocates grid points dynamically according to the evolving system, thereby reducing computational costs while preserving accuracy. We validate the method through two classical problems: the Smoluchowski limit and the Kramers escape problem. The truncated grid method shows excellent agreement with full grid approaches, offering a substantial reduction in computational time. Numerical results indicate that the truncated grid method serves as a robust alternative for solving the Boltzmann-BGK equation in computational kinetics.