A unified gas kinetic scheme with moving mesh and velocity space adaptation

Numerical simulation of flows from free molecular regime to continuum regime by a DVM with streaming and collision processes

“…The development of accurate and efficient numerical methods for simulating flows from free molecular regime to continuum regime has attracted much attention in recent years [1][2][3][4][5]. This is due to its valuable applications in the field of spacecraft [3,4], microelectromechanical systems (MEMS) [1,6], vacuum technology [7] and so on.…”

“…This is due to its valuable applications in the field of spacecraft [3,4], microelectromechanical systems (MEMS) [1,6], vacuum technology [7] and so on. The physical parameter used to characterize the degree of gas rarefaction is the Knudsen number (Kn), which is defined as the ratio of the mean free path to the characteristic length.…”

“…For flows in continuum flow regime, this requirement will lead to enormous computational costs. Other popular approaches to simulate rarefied flows include the discrete velocity method (DVM) or discrete ordinate method (DOM) [2,3,[17][18][19][20][21], the unified gas-kinetic scheme (UGKS) [4,6,22,23] and the discrete unified gas-kinetic scheme (DUGKS) [5,24]. In these methods, the particle velocity space is discretized into a finite set of points and the discrete velocity Boltzmann equation (DVBE) is solved.…”

“…By applying the above approaches, a number of flow problems from free molecular regime to continuum regime have been well resolved. Different from the above mentioned kinetic schemes [2][3][4][5][6][17][18][19][20][21][22][23][24], the semi-Lagrangian method [33][34][35] and lattice Boltzmann method (LBM) [36][37][38][39][40] have been devised and applied to simulate rarefied flows with streaming and collision processes. The semi-Lagrangian method is indeed a DVM.…”

Development of lattice Boltzmann flux solver for simulation of hypersonic flow past flight vehicles

“…Lattice Boltzmann Flux Solver (LBFS) is developed from Boltzmann equation-based method, including DVBE [9][10][11] (discrete velocity Boltzmann equation) and gas-kinetic schemes [12][13][14][15]. Gaskinetic schemes are more effective than DVBE.…”