Abstract:
The moving boundaries and the fluid-structure interaction are usually encountered in low/high-speed and continuum/rarefied flows. This paper presents a new framework based on the discrete unified gas kinetic scheme (DUGKS) for solving fluid-structure interaction problems in low-speed rarefied flows. The framework, which integrates an arbitrary Lagrangian-Eulerian method and a moving mesh technique, is validated by simulating continuum flows around forced- and free-oscillating circular cylinders. Satisfactory results are obtained, as the flow properties in the lock-in or non-lock-in regimes have been accurately captured and are in good agreement with existing work. Moreover, to take the rarefied gas effect into account properly when simulating rarefied flows with moving boundaries, the D2Q9 lattice model in continuous flows is replaced by the Gauss-Hermit quadrature rule in rarefied flows. Numerical results obtained by these two models for flows around a circular cylinder with forced oscillation are compared. Furthermore, the framework also can be used to simulate high-speed flows with moving boundaries, which has been justified by a numerical simulation of a forced-oscillating cylinder at
Ma = 5.0. All the test cases presented in this paper suggest that the proposed framework has a great potential for solving moving boundary problems in low- and high-speed rarefied flows.