Force Initial Level Set Renormalization

Force Initial Level Set Renormalization = <char_string>

Description / Usage

This card is used to invoke a renormalization step prior to the first time step of any transient computation.

<char_string>

YES|ON (not case sensitive) will cause the renormalization procedure to occur on the first step. If this card is not included or some other string is used here a renormalization will automatically occur on the first time step.

Examples

A typical length scale input card looks like:

Force Initial Level Set Renormalization = yes

Technical Discussion

Restarts occur fairly frequently during level set computations. It has been discovered that the robustness of the subsequent computation can be improved by quite a bit if the level set field is renormalized at the start of the restart, regardless of the current average gradient norm error. This card is employed to invoke a renormalization at the start of any computation, that is, a renormalization procedure is conducted prior to the initial time step if this card is present in the input deck. It has become standard operating procedure that when a level set computation runs into computational difficulty the first step in recovery should be to restart with a forced initial renormalization using this card.