How do I compute flows with natural convection in ANSWER?
There are three alternative ways: 1. Boussinesq Approach. This mode is invoked by the PROBLEM BOUSSINESQ command. In this mode density is assumed constant except for a “buoyancy” term in the momentum equation in the direction of the gravitational acceleration. See problem B.02 in ANSWER Examples . 2. Direct Source in Momentum Equation. This mode is invoked by a SOURCE command in the relevant momentum equation. See problem B.03 in ANSWER Examples . 3. Coupled gravity and Variable Density. This is the most comprehensive and mathematically exact formulation. See problem B.04 in ANSWER Examples . Example of each type is given in the B.02, B.03 and B.04 data set, respectively. The 1st and 2nd modes are essentially linearizations of the coupled mode. These should be tried to get a feel for the problem. In fact often these are good approximations provided the density change is less than a few percent. These are generally more stable than the fully coupled mode. Natural convection flows are no
