Discussion Forum

Hi,

I am doing a coupled heat transfer and mass transport problem for porous materials with gas (which has components air and water vapor) and water phases.

The energy equation that I have is something like this:

rho_eff * Cp, eff * dT/dt + grad [ (rho*cp*v) * T] = grad (Keff * grad T) + source term (1)

where grad means gradient.


Now the rho_eff and Cp,eff (properties of the mixture and are averages of phase properties weighted by their mass and volume fractions) in the first term is different than the rho and cp in the second term.

In the second term, the rho*cp*v term is defined as:

rho_w * v_w* Cp,w + rho_g * v_g *(omega_v * Cp,v + omega_a * Cp,a) - D*grad Cw *Cp,w
(rho_w and rho_g are the densities of water and gas, respectively; Cp,w and Cp,a are teh specific heat capacity of water and gas, respectively; v_w and v_g are the velocities of water and gas, respectively; omega_v and omega_a are the mass fractions of water vapor and air in the gas phase, respectively; Cw is the concentration of water)



For this case, how could I modify the heat transfer in solid node for the second term in equation (1)? Any clues are appreciated.



Thanks a million~~~