基于ib-lbm方法二维非定常流场内低维柔性物的数值模拟分析based on the ib - lbm method of two-dimensional unsteady flow field of low dimensional flexible numerical simulation analysis.docx

Abstract
Fluid structure interaction problems are very pervasive in industrial engineering and production practice. With the development of theory for fluid structure interaction putational science, numerical simulation of fluid structure interaction e a hot topic in field of fluid dynamics. However, due to its nonlinear and uncertainties of the interface, its simulation puts a great challenge to numerical techniques. Recently, there has been much progress in developing both methods Lattice Boltzmann Method (LBM) and Immersed Boundary Method (IBM). The proposed method called Immersed Boundary-Lattice Boltzmann Method (IB-LBM), which is employed to plex fluid dynamic systems. The author studied some improved models of IB-LBM, and proved the method is effective through discussions of flows around stational cylinder. The main contents and conclusions are as follows.
Brief discussion for fundamental theories of LBM and IBM.
Velocity correction method is an improved model of IB-LBM. Simulation of flows around stational cylinder is in the framework of velocity correction theory. Since the non-slip condition is accurately satisfied, no flow ration can be found in the present results. Compared with the traditional IB-LB Method, quality is conservation.
Application of multi-block approach in LBM. To demonstrate the present approach, cavity flow with different Reynolds number is selected. Compared with uniform grid method, flow field characteristics are represented more precisely with low Reynolds number, and the method can e high grid solution near the boundary. Fine mesh covers the blocks only in which the gradients are large. Owing to this improvement, multi-block strategy can substantially improve the accuracy putational efficiency for viscous putations.
Feed back law is introduced into IB-LBM, that is, the force term in Boltzmann equation is feed back force, and we called this strategy feed back method. The simulation of flows around stational cylinder in two-dimens