Temp: Difference between revisions

From CIRPwiki
Jump to navigation Jump to search
Deleted (talk | contribs)
No edit summary
Deleted (talk | contribs)
No edit summary
 
(12 intermediate revisions by the same user not shown)
Line 1: Line 1:
This is a page for setting up pages before loading them.
This is a page for setting up pages before loading them.


The discretized momentum equations are  
<math> \int\limits_{A}{\nabla \cdot \left( {{\Gamma }^{\phi }}h\nabla \phi  \right)}\text{d}A=\oint\limits_{S}{{{\Gamma }^{\phi }}h\left( \nabla \phi \cdot \mathbf{n} \right)}\text{d}S=\sum\limits_{f}^{{}}{\bar{\Gamma }_{f}^{\phi }{{{\bar{h}}}_{f}}\Delta {{l}_{f}}{{\left( {{{\hat{n}}}_{i}}{{\nabla }_{i}}\phi  \right)}_{f}}} </math>
 
First the momentum equations are rewritten as
{{Equation| <math> \frac{\partial ( h U_i ) }{\partial t}
+ \frac{\partial }{\partial x_j} \biggl( (h U_i U_j )-  \nu_t  h \frac{\partial U_i }{\partial x_j} \biggr)
= - g h \frac{\partial \eta }{\partial x_i} + S_i
</math>|2=1}}
 
where <math>S_i</math> includes all other terms. The equation is then integrated over the a control volume as
{{Equation| <math> \frac{\partial  }{\partial t} \int_A h U_i dA
+ \oint_F \frac{\partial }{\partial x_j} \biggl[ (h U_i U_j) -  \nu_t h \frac{\partial U_i }{\partial x_j} \biggr] dF
= - g h \oint_F \frac{\partial \eta }{\partial x_i} dF + \int_A S_i dA
</math>|2=2}}
 
The resulting di
 


<math> U_{i,P}^{n+1} = \frac{1}{a_{i,P}} \biggl( \sum_{k=1} a_{i,k} U_{i,k}^{n+1} + S_i \biggr)  
<math> U_{i,P}^{n+1} = \frac{1}{a_{i,P}} \biggl( \sum_{k=1} a_{i,k} U_{i,k}^{n+1} + S_i \biggr)  
- \frac{h_P}{a_{i,P}} \sum_{k=1} n_i n_k  \Delta s_k p_k^{n+1}
- \frac{h_P}{a_{i,P}} \sum_{k=1} n_{ik} \Delta s_k p_k^{n+1}
</math>
</math>


where the subscript <math>k</math> indicates the cell face, <math>p = g \eta</math> with <math>\eta</math> being the water surface elevation, <math>n_i</math> is the unit vector in the <math>i</math> direction, and <math>n_k</math> is the unit vector normal to the cell face.
The continuity equation is discretized as


The coefficient a_{i,P} is equal to <math> a_{i,P} = \sum a_{i,k} + a_P^0 </math>
<math> h^{n+1} -  \mathbf{S} </math>
 
 
where the subscript <math>k</math> indicates the cell face, <math>p = g \eta</math> with <math>\eta</math> being the water surface elevation, <math>n_{ik}</math> is equal to the dot product of the velocity unit vector and the cell face unit vector.
 
The coefficient <math>a_{i,P}</math> is equal to <math> a_{i,P} = \sum a_{i,k} + a_P^0 </math>


The continuity equation is discretized as
The continuity equation is discretized as
<math> p_P^{n+1} = p_P^n - g \frac{\Delta t}{\Delta A_P} \sum_{k=1} n_k F_k^{n+1}</math>
where <math>n_k </math> is the dot product of the cell face unit vector and


The depth-averaged 2-D continuity and momentum equations are given by
The depth-averaged 2-D continuity and momentum equations are given by
Line 17: Line 41:


for  <math>  j=1,2  </math>
for  <math>  j=1,2  </math>
{{Equation| <math> \frac{\partial ( h U_i ) }{\partial t} + \frac{\partial (h U_i U_j )}{\partial x_j}
- \epsilon_{ij3} f_c U_j h = - g h \frac{\partial \eta }{\partial x_i}
- \frac{h}{\rho_0} \frac{\partial p_a }{\partial x_i}
+ \frac{\partial }{\partial x_j} \biggl ( \nu_t  h \frac{\partial U_i }{\partial x_j} \biggr )
+ \frac{\tau_i }{\rho}
</math>|2=2}}

Latest revision as of 19:00, 17 March 2011

This is a page for setting up pages before loading them.

A(Γϕhϕ)dA=SΓϕh(ϕ𝐧)dS=fΓ¯fϕh¯fΔlf(n^iiϕ)f

First the momentum equations are rewritten as

  (hUi)t+xj((hUiUj)νthUixj)=ghηxi+Si (1)

where Si includes all other terms. The equation is then integrated over the a control volume as

  tAhUidA+Fxj[(hUiUj)νthUixj]dF=ghFηxidF+ASidA (2)

The resulting di


Ui,Pn+1=1ai,P(k=1ai,kUi,kn+1+Si)hPai,Pk=1nikΔskpkn+1

The continuity equation is discretized as

hn+1𝐒


where the subscript k indicates the cell face, p=gη with η being the water surface elevation, nik is equal to the dot product of the velocity unit vector and the cell face unit vector.

The coefficient ai,P is equal to ai,P=ai,k+aP0

The continuity equation is discretized as pPn+1=pPngΔtΔAPk=1nkFkn+1

where nk is the dot product of the cell face unit vector and


The depth-averaged 2-D continuity and momentum equations are given by

  ht+(hUj)xj=S (1)

for j=1,2