[jcamilleri]

Hi all,

I am conducting a grid dependence study for a free falling wedge impacting the water surface. Core mesh base size and time step are divided by the same factor (2 in this case) and the resulting surface average pressures are compared.

My question is, should the 'total' thickness of the prism layer be kept constant (i.e. using an absolute value for the prism layer thickness) or divided by the same factor (i.e. using the relative value setting)? In my opinion, I think that it is better to specify a relative size rather than an absolute one to keep the same thickness ration between the last prism layer and the core mesh. I have tried both options however when using the absolute size, it becomes very difficult to maintain the same CFL, which when doing a grid dependence study in a transient simulation I think is critical.

Also, when using the relative size option and keeping all other settings (number of prism layers and stretching factor) the same, the thickness of the 1st prism layer is also divided by 2. This is the correct approach right, I mean, if I am dividing the core mesh by a factor of 2 it makes sense that the thickness of the prism layers is also divided by 2?

Am I making sense?

Thanks and regards,

Josef