An integer array representing the interpolation option used to derive dq on each level. There should be at least MaxLevel elements in this array. The options are as follows:

• -1 = centered: Takes the average of dqbackward and dqforward.
• 0 = constant: Uses a constant option for dq.
• 1 = minimod: Takes the minimum between a forward-step dq and a backward-step dq.
• 2 = superbee: Uses a constant option for dq.
• 3 = vanleer: Always uses the backward-step dq.
• 4 = monotonized-centered: Always uses the forward-step dq.

The following chunk is from a previous version. The option 1 below apparently referred to the constant option. However, it seems that now people are using the current option 1, minmod…

When using AMR, there is a possibility of errors (density, pressure protection) when using the gradient or average options, particularly if you have a large density jump bordering a domain decomposition line.

This can be solved by using option 1. Incidentally, this is also more correct if your initial problem setup has a large density jump between two cells in pressure balance with the same velocity (a density contact discontinuity). In this way, your child cells will not take the average or gradient between a very large density and a very small density, instead taking the same value as the parent.