อมร คุ้มทรัพย์สิริ. An Application of the Smoothed Particle Hydrodynamics to the Barotropic Vorticity Equation. Master's Degree(Applied Mathematics). King Mongkut's University of Technology Thonburi. : King Mongkut's University of Technology Thonburi, 2005.
An Application of the Smoothed Particle Hydrodynamics to the Barotropic Vorticity Equation
Abstract:
Smoothed particle hydrodynamic (SPH) method is applied to the barotropic vorticity
equation in the atmosphere. The weight function for this SPH approximation is cubic spline function. Before applying SPH approximation to the vorticity equation, two additional equations are approximated first to investigate if there is any problem. These two equations are an equation of a sphere and the linear advection equation. Results from SPH approximations of the basic equation show that errors can occur if the support domain is too large. Also at the boundary of the domain, asymmetry in weight function causes serious error. This problem can be partially solved by using ghost particle technique. For the linear advection equation, errors occur if the smoothing length for derivative approximation is too small. To reduce the error, relatively large value of the smoothing length for derivative is required. There is also phase speed error in the approximated solution of the advection equation, this error is reduced by applying
a new weight function with adjusted factor. The applications of SPH method to the
barotropic vorticity equation consist of a simple localized vorticity configuration in five different initial basic flows. The results show that with simple basic flows the SPH method perform well. However, when the basic flow has a complex pattern, large error can occur near the boundary due to asymmetry of weight function at the boundary.