Investigation Of Liquid Flow In The Nano-field By SPH Method

The numerical simulation and the SPH of meshless are briefly reviewed in this thesis. There are two fundamental simulation methods for numerical simulation: the simulation based on mesh and simulation based on meshless. The simulation based on mesh can be divided into two descriptions: the Eulerian description and the Lagrangian description. The Eulerian description is a spatial description, and is typically represented by the finite difference method (FDM). The Lagrangian description is a material description, and is typically represented by the finite element method (FEM). The mesh method has much defect in applying in many problems such as large deformations, large inhomogeneities, moving material interfaces, deformable boundaries, and free surface etc. The new method named meshless is developed. The key idea of the meshless method is to provide accurate and stable numerical solution for integral equations or PDEs under all kinds of possible boundary conditions with a set of arbitrarily distributed nodes (or particles) without using any mesh that provides the connectivity of these nodes or particles. The SPH as one kind of meshless is using broadly in flow mechanics region because of not using mesh.It has done well for studying the Argon fluid in the macroscopical fields with SPH method, but only little about the microcosmis fields. The smoothed particle hydrodynamics (SPH) has been adopted in this paper to investigate the characteristic of Argon flow in the nano-field. The status and the flow vector chart in different time for Argon flow are obtained. The effect of the wraparound and the sawtooth are found during the simulations. The reason for effect of the wraparound is because of periodical boundary condition and effect of sawtooth is because of small size effect.For Poiseuille flow, it can be seen from the flow vector chart that the middle velocity of the flow is highest just agreement with the actual situations. For Couette flow, the velocity of the flow around upper board is same as the velocity of the board. The velocity decreases from upper board to lower board. The simulated results are agreement with theoretical results. This verifies the validity of the SPH in nano-field...