mass transfer

Trying to figure out an equation for the rate mass transfer for the 1D model of the Desert Fridge.

This is the missing link. If we can figure this out the heat transfer equations are pretty straight forward (i think) as for a steady state system the rate of mass transfer at section will be constant it will be equal to the mass of water vaporising - multiply this up by the latent heat of vaporisation (which is actually significantly different at different temperature - dont really understand why but here is one explanation) and we have the heat trasnfer due to evaporation from which we can deduce the final inside temperature as attempted in the 1D model of the Desert Fridge.

Now according to Anas Rana, the mass flux will be given by solving some differential equations and he reckons he can do this. I have no idea how this works so I have email him all the stuff we have and waiting on a reply from him.

In the meanwhile I am reading up on the sections of Transfer Processes by D.K Edwards as suggested by Dr Nadeem sb in our last meeting (10/7/2010), which may help in making sense of all this.