[engahmed]

Hi,
Can the Boussinesq approximation be emplaoyed in a bouyance flow problem with a temperature difference of about 100 degrees?
The manual says that the Boussinesq approximation is applicable when
B(T-To)<<1 where , B is the coeffecient of thermal expansion, To is the operating temperature.
The fluid in my case is water, and the flow is in a porous medium superimposed by a water layer.
I am not getting convergence, and the residuals keep oscillating. Even when I use a smaller temperature difference.
Any help will be appreciated.
Thank you