FLOOD06499

• County: Statewide
• Basin: Statewide
• Title: Development of Generalized Free Surface Flow Models Using Finite Element Techniques
• Date: 2/1/1979
• Prepared For: US
• Prepared By: COE
• Floodplain - Doc Type: Educational/Technical/Reference Information

"'''.JF
_'.1"
:uu _ ;
,l.. rn.

.. _ ."""" ,,., <Ie"

, - -- ........... . ~
// - --------............ .....
// --- ~------'"----..........---.......--....
~:.--'" - ------~_.----"'--..
- -- ~ ... - :::. ,.-7 -_-: =~~~:~:;;::.--==:::.= ~~
----- -- ,./--=---==-----~ ~~~ ~ -----------
---~------ - --~-~-------------""--------.......----
--------------==:::::::::: -= ----=~ =~-~~--------~.::--:-~:-:..~~-~ :::::--
--::..--::: -:::::.. - - - - - -- - - -=-..::---~--'-.::..----.~~-:--.~~
...--- ~ ~ ~~~",-
~~- ~-,~
~- -~
,-

Fi gure g

Velocities for Spillway Q = 7000 cms (250,000 cfs),
Existing Powerhouse Q = 6500 cms (230,000 cfs),
Stagnation Point Boundary Conditions

TWQ-:JIMEIlSIOtlAL MODELS IN THE VERTICAL PLANE

/'

Two-dimensional (longitudinal and vertical) hydrodynamic models
have been developed to aid the Corps in the description and
analysis of reservoir water quality. The importance of the
longitudinal as well as the vertical exchange in long,
relatively narrow and deep im;Joundments has been studied by
Pritchard (1971), Anthony and Drummond (1973) and the Tennessee
Valley Authority (1969). Investigations such as these have
shown that the hydrodynamics of a stratified reservoir in-
fluences the \'iater. quality and, therefore, the biological
productivity of deep impoundments. Additional objectives for
the development of multidimensional models are to be able to
pl'edict the effects that outlet type and location, degree of
stratification. and reservoir operation have on the water
quality in downstream rivers .wd streams.
As well as the general interest in simulating flows in
the vertical plane, this research has provided the opportunity
to compare the perfonnance of an implicit finite difference
method (FDM) model with that of a finite element method (FEM)
model. The FDM model was developed by Edinger and Buchak (1977)
and is named LARM (Laterally Averaged Reservoir Model). The
FEM vertical model was developed by Nortonet a1 (1973) and King
et a1 (1975). Although initial development of the vertical FEM
lllode1 \'ias accomplished at the same time as that of the hori-
zontal model previously discussed, further refinement and use
of the vertical model has lag~ed considerably.
The primary objectives of the comparison of these two
hydrodynamic models were: (1) to compare the relative ease
with which the required data and boundary conditions could be
prepared and coded; (2) to cOl,]pare the overall performance of