Rayleigh-Benard problem with buoyanBoussinesqSimpleFoam
 

Hi Foamers

I was wondering if anyone has tried solving the classical Rayleigh-Benard problem with buoyanBoussinesqSimpleFoam?

I have been trying to solve it for the following case:

Laminar, steady-state and 2D flow
free-free boundary condition
Pr = 0.72
Ra = 3000
H= 1
L = 10
Thot = 1
Tcold = Tref = 0
g = -1
beta = 1
nu = 0.01549193

nu is obtained from the Ra number relationship
nu = 1/(alpha*Ra) = Pr/(nu*Ra)
thus nu = sqrt(Pr/Ra)

From what ive found Ra_crit should be around 657.51, i.e. any Ra number smaller than that will have no convection. Thus for Ra = 3000 i should indeed have convection for this case.

However I am not getting any convection when OpenFOAM solves this case. I get a pure conduction solution with 10 W heat flux at the top and bottom faces. If solved in Fluent i get the correct solution.

Any advise would be appreciated

Rayleigh benard convection
 

Did you get the result for convection. i am also doing and struggling to get the results ?

Hello,

hae a look at the Mukul P. post named "unsteady solver in OpenFoam" (the name is not explicit indeed). Sorry I don't konw to put the link:rolleyes: but it is one of the last on the forum.

He looks at the same things than you I guess.

You should work together maybe.