A theoretical framework of information preservation method and its application to low-speed nonequilibrium gas flows

Simulations of nonequilibrium gas flows have garnered significant interest in modern engineering problems involving rarefied flow characteristics. Despite the popularity direct simulation Monte Carlo (DSMC) method simulating such flows, its use low-speed is limited by statistical noises. The information preservation (IP) a promising alternative known for low noise properties. In this study, new theoretical framework IP based on kinetic theory introduced to offer complete understanding transport properties preserved information. Specifically, we introduce velocity-information joint distribution function (VIJDF) and derive governing equation as well corresponding macroscopic equations. To ensure accuracy method, total stress/heat flux IP, including generated during movement collision steps compensation imposed step, matched molecular DSMC. end, model VIJDF proposed evaluate flux. parameters are theoretically determined equating coefficients associated with viscosity thermal conductivity Numerical simulations variety Couette flow, Fourier high-speed external force-driven Poiseuille lid-driven cavity creep demonstrate that can achieve similar DSMC much smaller sampling size.