For time-dependent problems, time-marching scheme parameters apply to all sub-tasks. Note that some numerical parameters specific to a particular sub-task are defined in the Interpolation menu of the sub-task. For example, in the case of power law fluids (or, more generally, generalized Newtonian fluids with a low power law index), it has been found that, in many circumstances, the Newton-Raphson method does not converge. It is then necessary to shift from the Newton-Raphson method to Picard iterations, in which the viscosity is updated in terms of the last velocity field. The general recommended procedure is to require a few Picard iterations, followed by the Newton-Raphson method. For details, see Viscosity-Related Iterations.

You can modify the numerical parameters relevant to the time-marching scheme by selecting Modify the transient iterative parameters in the Numerical parameters menu.

For more information on time-marching parameters, see Time-Dependent Flows.