Numerical Investigation of Shallow-Water Pollutant Transport Problems with Smoothed Particle Hydrodynamics Method
Date Issued
2012
Date
2012
Author(s)
Chang, Yu-Sheng
Abstract
In this research, Smoothed Particle Hydrodynamics (SPH) is applied to solve the transport of pollutant problems shallow water flow. SPH method is a meshfree numerical method under the Lagrangain viewpoint. Under this viewpoint, the non-linear advective terms of the fluid governing equations does not need to be discretized. Furthermore, SPH method can easily deal with the large deformation problems such as free surface, dry-wet interface and the super/subcritical mixed flow problems. Hence, this is why it is very suitable to be introduced in this work to investigate the pollutant transport problems in arbitrary flow conditions on the ground.
First, the benchmark tests, like the top hat tracer distribution and impulse point release, are used to demonstrate the advantages of this pollutant transport model compared to the results of previous studies, and then the numerical sensitivity is performed with different particle numbers. The pollutant transport model set up in this research not only can handle the flow conditions of entire range of Peclet numbers from zero to infinity, but also produces few numerical dispersion and numerical oscillations when compared with traditional grid methods. In addition, the simulations always have the reasonably accurate results. Afterwards, the flow over a bump is used test the abilities of this model on solving the advection-diffusion equation under the open boundary conditions and the irregular terrain conditions. Next, one kind of the Riemann problems, i.e. the dam break problems, is carried out to examine that the pollutant transport model is able to obtain the concentration distribution of the pollutant precisely, even encountering shocks or rarefaction waves in the flow field. The final part focuses on the two dimensional shallow water flow–the two dimensional uniform. The concentration field of the pollutant distribution is observed when the advective transport process and the diffusive transport process are occurred in mainstream direction or in lateral direction. In general, the pollutant transport model established under the SPH frame has proved its efficiency and reliability by above numerical results and case comparisons.
Subjects
Smoothed particle hydrodynamics
Shallow water equations
Numerical simulation
Pollutant transport problem
Advection-diffusion equation
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
index.html
Size
23.49 KB
Format
HTML
Checksum
(MD5):a8945304f798552f49323087d612503d