Numerical Study Of Splashing Flows Based On Lattice Boltzmann Method

Splash flow i s a kind of unste ady gas-liquid two-phase flow, whose ga s-liquid interface moves violently. In recent years, numer ical studies on such issue are increasing, but either comput ati onal accuracy or scale of the numerical methods on splash flow could not me et the requirement, especi all y for the simulation of large-scale s plashing phenomena. However, Lattice Boltzmann M ethod(LBM) based on the ki neti c theory of me soscopic equati on, has great potential on t he study of splash flow, because i t reflects both macroscopic a nd micr oscopic char acteristics of fluid syst em.This paper attempts to develop a LBM method for the simulation of splash flow. At first,ba sed on the singl e-phase free surface LBM model, and by introduc ing the gravity, moving bounda r y, turbulence into the model, the method is modified to be suitable for the simulation of splash flow. Then the MPI and CUDA programming standards for t he parallel computat ion are used respectively t o accelerate the LBM pr ogr am, a nd both results show t he good acceleration e ffect. As the LBM MPI program could be used for larger calculation scale, t his paper apply it t o t he studies on splash flow of wate r entry.Finally, We a pply the de veloped LBM mode l to a three-dimensional numerical case of wat er- entry disc, and excel lent numerical accuracy is proved. Then, a two-di mensional numerical case of wat er-entry wedge i s simula ted, and the press ure evolution of flow field and t he pressure distribution on wedge surfac e a re obtained, which agrees well with the references resul ts. At l ast, a three-dimensional numerical c ase of wat er-entry wedge is simulated for the study on the factors that influence the splashing chara cter istics in wat er-entry problems,i ncludi ng grid fac tors and hydrodynamic fac tors, and by this study we obtain the grid par ameters suitable for engine ering applications, and Fr/Re numbe r range by whi ch the splashing shape is significa ntly influenced. The studies in this paper show that the LBM method has a great pot enti al for applic ation in numerical si mulation of splash flow, and that the devel oped LBM model has la id a strong founda tion for t he deeper study of splash flow.