Numerical modelling of propagation of dam break wave front and resulting flash flood | |
| Author | Winyu Rattanapitikon |
| Call Number | AIT Thesis no. WA-91-26 |
| Subject(s) | Flood control--Mathematical models Dam failures |
| Note | A thesis submitted in a partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Flood waves resulting from instantaneous breaking of a dam are computed by using a 2-D mathematical model consisting of the unsteady free surface flow equations. The equations namely the continuity, x- and y- momentum equations are solved numerically using the two step predictor-corrector method in conjunction with the asymmetric finite difference scheme. The computed results of the present model are verified by using the experimental results obtained from a physical laboratory model simulating two dimensional propagation of dam-break wave over a dry bed flood plain. The results of verification indicate that the present model can be applied to simulate 2-D propagation and spreading of dam-break wave front very well. The model can predict the flood depth hydrographs fairly near the dam-break section but a prediction of depth is achieved at a further distance downstream. This is envisaged to be due to the effect of the moving hydraulic jump caused by hydraulic resistance of flood plain and reflection from the downstream end. The computed results from the present model and the previous model developed by Wattanaprateep (1987) are also compared. It is found that the results of the present model are closer to the experimental results than those of Wattanaprateep's model. Sensitivity analysis on the performance of the present model is carried out. It is found that (i) the Manning roughness coefficient has significant effect on the computed results, (ii) the small depth in the friction terms and the limiting depth of wave front have a small effect on the computed results of wave front spreading pattern and speed of the wave front propagation over the dry flood plain, (iii) no slip condition at closed wall boundary is suggested in this study and also the use of predictor-corrector method conjunction with the asymmetric finite difference scheme is suggested to simulate the flood wave propagation on dry bed before the reflection of moving hydraulic jump from the downstream end occur. After that only the asymmetric finite difference scheme is suggested. |
| Year | 1991 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Tawatchai Tingsanchali |
| Examination Committee(s) | Suphat Vongvisessomjai ;Shibayama, Tomoya |
| Scholarship Donor(s) | The Government of Netherlands |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1991 |