Different lengths for cells ?

[Nicolas Jacquemet]

Hi David,

With -lengths under TRANSPORT, it is possible to define cells with different lengths (Delta x). But, obeying to the 'Courant condition' (equation 108 of the version 2 user's guide) implies that for a given time step and pore water flow velocity, Delta x has a unique value. Thus, can you explain why it is possible to define different Delta x's ?

Many thanks for your answer,

Nicolas J.

[dlparkhurst]

The cell volume is generally the same for each cel, regardless of the cell length. The cell volume is replaced each time step by the volume in the upstream cell. So, the velocity of the water in the cell is length divided by time step. Cells with different lengths have different velocities.

[Nicolas Jacquemet]

OK, thank you David for your answer.

Nicolas