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Persistent URL http://purl.org/net/epubs/work/50494
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Record Id 50494
Title Oscillatory shear-driven gas microflow study with the lattice Boltzmann method
Abstract Oscillatory Couette flow is a simple and typical approximation for time-periodic shear-driven gas flows which have a broad range of applications in a variety of oscillating microstructures, such as microresonators, inertial sensors, comb-drive actuators, and computer hard-drives. Flows in these miniaturised devices are often low speed and non-equilibrium. The direct simulation Monte Carlo (DSMC) method is usually employed to investigate the flow physics in such unsteady non-equilibrium microflows and important results of oscillatory flow and heat transfer characteristics have been achieved. However, the statistical scattering and computational memory requirement associated DSMC usually make it difficult and inefficient for these low speed flows. An alternative kinetic method, the direct solution of the Boltzmann equation, can offer accurate solution. However, due to the inherent nonlinearity, complexity of the collision integral terms, and the multidimensionality of the equation, the solution is limited to simple geometries. Meanwhile, analytical solutions, usually using continuum-based models with velocity-slip boundary conditions, though simple and convenient, fail to capture the Knudsen layer. In this paper, we introduce the lattice Boltzmann (LB) model as an alternative method to investigate oscillatory non-equilibrium gas flows. Due to its intrinsically kinetic nature, the LB approach to simulating non-equilibrium gas flows has recently attracted significant research interest. In comparison to DSMC, the method offers a significantly lower computational cost and can handle complicated geometric configurations. In addition, the LB method does not suffer from closure and boundary condition problems associated with high-order continuum methods, such as Grad's 13-moment models. More recently, by developing high-order LB models, and LB models coupled with a wall function or local mean free path [5], the nonlinear Knudsen layer has been captured successfully. However, to the authors' knowledge, the LB models have not been employed to study oscillatory non-equilibrium flows. In the present study, we extend the LB model, coupled with local mean free path, to investigate unsteady non-equilibrium Couette flow between two infinite parallel plates
Organisation CSE , CSE-CEG , STFC
Keywords Physics , Engineering
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Language English (EN)
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Paper In Conference Proceedings In 5th International Conference for Mesoscopic Methods in Engineering and Science (ICMMES), Amsterdam, Netherlands, 16-20 Jun 2008, .