Smoothed particle simulation of gravity waves in a multi-fluid system

The generation and propagation of gravity waves in a multi-fluid system have significant environmental impacts. This paper presents an incompressible smoothed particle hydrodynamics model to simulate this process. The method is a mesh-free particle modelling approach that can treat the free surfaces and multi-interfaces in a straightforward manner. The proposed model is based on the general multi-fluid flow equations and uses a unified pressure formulation to address the interactions among the different components of the fluids. The model will be used to investigate the gravity currents generated from one fluid intruding into other fluids with different densities. The general features of the gravity current have been disclosed and the computed gravity wave height and wave propagation speed agree well with the theoretical analysis. The error analysis proved the convergence of the numerical scheme and it was found that the multi-fluid model is close to first-order accurate.