How can you get good convergence when simulating heat transfer in a closed room?
Closed rooms have no outlets or openings so there is no boundary for the solver to use as a pressure reference region. In addition, if there is heat transfer into the room it will heat up and the pressure will increase. The following advice should improve convergence: (1) Compute an expression for the average room pressure from P = <rho>*R*<T>/W, where <> implies volumed averaged. For example: AverageDensity = volumeAve(density )@Domain 1 AverageTemperature = volumeAve(T)@Domain 1 AveragePressure = AverageDensity*R*AverageTemperature/W The above expression for the average pressure assumes that W is the molecular weight of the fluid and that an ideal gas is being used. (2) Set the reference pressure equal to the average room pressure. (3) Run in double precision. 

