| Author | Gao Jiacai |
| Call Number | AIT Thesis no. WA-92-8 |
| Subject(s) | Hydrodynamics--Mathematical models
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Flow energy dissipation due to an abrupt bed drop was previously studied extensively on a
macroscopic scale, either by a one-dimensional (1-D) analysis or by experimental measurement.
The macroscopic aspect of the flow phenomena and energy dissipation is well understood while the
microscopic aspect has not been revealed clearly.
A two-dimensional (2-D) hydrodynamic model in the vertical plane with the standard k - e
turbulence model closure (VEST model) is used to compute the temporal mean flow parameters
and turbulence characteristics of the flow through an abrupt bed drop in a microscopic scale. The
numerical results are compared with the available experimental measurements. It is found that the
model can predict the velocities accurately and can predict the turbulence characteristics reasonably
well. The spatial distribution of the flow energy dissipation is computed along the longitudinal
distance and a good agreement between the computed results and the previous experimental data is
obtained. The effects of the inlet Froude number, the relative step height and the downstream end
water level on the energy dissipation are examined. The computed energy dissipation is compared
with those obtained by the classical 1-D analysis. The deviations of 1-D results from the 2-D model
results are quantitatively evaluated.
Sensitivity analysis are performed to investigate the effects of the k - e model constants, the
upstream boundary conditions of the inlet velocity and the k and e turbulence characteristics, and
the effects of the water surface boundary condition on the computed flow conditions and on the
flow energy dissipation. |
| Year | 1992 |
| 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 ;Tanaka, Hitoshi ;Tran Thuc
|
| Scholarship Donor(s) | Government of Denmark |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1992 |