Difference between revisions of "Contrib/CompressibleMixingPhaseChangeFoam"

Revision as of 19:53, 28 December 2012

Solver for two fluids with phase change (for example - water <---> steam), pressure and temperature density dependence

* Equation of state
* Liquid volume transport

Let us consider transport of liquid (heavy phase) volume fraction $\alpha_l$ :

$\frac{\partial \alpha_l \rho_l}{\partial t} + \nabla \cdot \left ( \right )$

$\frac{\partial{T}}{\partial t} + \nabla \cdot \left(\mathbf{U} T\right) - \nabla \cdot \left( (D_T + \nu_{turb}/Sc_{turb}) \nabla T \right) = 0$

The mass transfer coefficient is determined at each wall by assuming that the value of T at the wall is zero:

$k_c=-\frac{D_T}{T_b} \frac{\partial T}{\partial y}|_{y=0}$

where $T_b$ is the bulk value of T and y is the direction normal to the wall.

The Sherwood number is then determined by:

$Sh=\frac{k_c d}{D_T}$

where d is the characteristic dimension.

In order to use the solver, you should add $D_T$ , $T_b$ and d to the transportProperties dictionary.

The solver is based on turbFoam, with the transport of a scalar T having a mass diffusion coefficient $D_T$ :

* Phase change model
* Momentum equation
* Energy equation

@@ Line 5: / Line 5: @@
   * Liquid volume transport
 Let us consider transport of liquid (heavy phase) volume fraction <math>\alpha_l</math>:
+<math>
+\frac{\partial \alpha_l \rho_l}{\partial t} + \nabla \cdot
+\left (
+\right )
+</math>
+<math>
+\frac{\partial{T}}{\partial t} + \nabla \cdot \left(\mathbf{U} T\right) - \nabla \cdot \left( (D_T + \nu_{turb}/Sc_{turb}) \nabla T \right) = 0
+</math>
+The mass transfer coefficient is determined at each wall by assuming that the value of ''T'' at the wall is zero:
+<math>k_c=-\frac{D_T}{T_b} \frac{\partial T}{\partial y}|_{y=0}</math>
+where <math>T_b</math> is the bulk value of ''T'' and ''y'' is the direction normal to the wall.
+The Sherwood number is then determined by:
+<math>Sh=\frac{k_c d}{D_T}</math>
+where ''d'' is the characteristic dimension.
+In order to use the solver, you should add <math>D_T</math>, <math>T_b</math> and ''d'' to the transportProperties dictionary.
 The solver is based on turbFoam, with the transport of a scalar ''T'' having a mass diffusion coefficient <math>D_T</math>: