| Author | Luo, Ching-ruey |
| Call Number | AIT Thesis no. WA-88-9 |
| Subject(s) | Hydraulics--Graphic methods
|
| Note |
A thesis submitted in partial fulfilment of the requirement for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | For a steady flow, the .rating curve is unique for a
nonerodable section where the flow is uniform, but it is a loop
for an erodible section when the flow is nonuniform.
unsteady flow, the rating curve does exist, but it is
complicated, i.e. relationship between water level and
velocity effected by flood hydrograph or tide.
more
flow
A more general relationship between water level and flow
velocity (or discharge) with flood hydrograph from upstream and
tide from downstream for time-dependent is derived analytically
from diffusion equation and continuity equation. The upstream
and downstream boundary conditions are expressed in terms of
harmonic functions rather than a step function. The analytical
solutions are compared with the numerical results obtained by
using finite . difference model with implicit scheme based on the
complete Sanit-Venant equations for unste"dy flow in open
channel.
It is found from the study that: the peak flow times at
different locations are shifted due to the kinematic wave
velocity; therefore, the rating curves at different locations are
spread, not complete a loop like peacock tail feather. The
rating curves for the subcritical flows are below the line of Y*
= q*, and h~ supercritical flow rating curves are above y* = q*.
The dime1:si0nless amplitude due to downstream tide is still a
function of time not only function of position. The comparison
between the analytical results and numerical results are in good
agreement, not only for the weighting factor, Pt = 0.70, but also
for Pt = 0.50. This analytical model can be used without any
sophisticated computing machine; in fact, a simple desk
calculator and a table of error function are sufficient in
carrying out the computation based on the analytical solution. |
| Year | 1988 |
| 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) | Suphat Vongvisessomjai |
| Examination Committee(s) | Tawatchai Tingsanchali ;Nielsen, Steen Asger |
| Scholarship Donor(s) | Taiwan Provincial Government,
Chinese Taipei |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1988 |