Hi I am working on water tank and i need to capture natural convection in the tank.I dont want to use boussinesq model, as the temperature range(5 C~ 30 C) is large. To make the density of water as fuction of local temperature in the domain,I tried adding expression for density as some function of temperature through the expression tab provided near the density window in the material property.However my solver fails. I have been trying to solve this for long time,can anyone help me in setting this problem

Danish

Use a limited temperature within your expression something like maxVal(minVal(T,303[K]),278[K]) otherwise the expression might evaluate to a negative density for certain types of equations. You can also try to limit the table generation of the fluid properties to a minimium and maximum temperature. 'Table generation' can be found in the 'Material Properties' tab when defining a non-constant property fluid.