COEFF_dt_coll

Default: COEFF_dt_coll = 0.0 (off) If a value bigger than zero is specified for this parameter, the timestep criterion \begin{align} dt = C_{coll} \sqrt{\frac{m_i}{k_i}} \quad \forall i\end{align} is introduced. Where \( m_i\), \( k_i\) are the minimum mass, maximum \( k\) of the particles involved in interaction, respectively. This time step criterion is particularly relevant in case DROPLETPHASE interactions are computed. For DROPLETPHASE particles that are potentially in a collision with other particles or a wall, the timestep is reduced by this criterion in order to guarantee a good timestep resolution of the collision. If this time step criterion leads to a very strong time step restriction, performance can be improved by using COMP_DropletphaseSubcycles.