| Summary: | 碩士 === 逢甲大學 === 土木及水利工程所 === 91 === In this study, a finite difference method was used to solve the shallow water equations. In order to reduce this non-physical oscillation, investigate numerical flux compared Upwind and Lax-Wendroff type with the one-parameter limiter (OPL) and two-parameter limiters (TPL) to conform Total Variation Diminishing (TVD) form. Used TVD scheme for computation of one dimension and two dimension unsteady shallow water problem.
This study discussion the result divide into two parts after simulated. First is the one dimensional shallow water problem simulations, tested horizontal dam break flow, ramp dam break flow, bed hump flow and wave bored problems. We found the one dimensional Riemann solution and the U.S. Corps of engineers (1960) WES experiment data verified the model. When finished one dimensional shallow water problem tests, we used the result of the one dimensional shallow water problem to simulated two dimensional gap dam break and block flow problem. Several limit function to test one dimensional problem. By the test result, we discovered when the initial downstream depth is deep; the simulated result of OPL limit function is better than TPL limit function. On the contrary situation the simulated result of TPL limit function is better than OPL limit function. We also obtain the Minmod or MUSCL limit function simulated result is better than others. If don’t consideration of the broken wave. When to cope with Transcritical flow our model have good effect. Finally we discuss dam break wave pass through the square obstacle in the channel problem. We used boundary condition assume process computed if square obstacle is taller than initial surface. Our mondel can provide a good numerical method for solving multi-dimensional and shallow water problems.
|
|---|
