The following beta features are available when you have selected a second-order Transient Formulation in the Solution Methods task page:
You can enable the variable time step size formulation (as described in the Fluent Theory Guide and the Fluent User's Guide) for dynamic meshes. Note that this combination is only available with the pressure-based solver, and that dynamic meshes are not compatible with the Bounded Second Order Implicit formulation.
You can enable a variant of that time formulation that provides better solution stability and boundedness. Note that these variants are available for both Second Order Implicit and Bounded Second Order Implicit formulations, and have the following limitations:
They are not available with the density-based solver, only the pressure-based solver.
They are only applicable to the implicit volume fraction discretization schemes for multiphase, and not to the explicit volume fraction schemes.
They do not support the Singhal et al. cavitation model.
Note that if one of these variants is enabled for a case that uses a species model (not including Species Transport), you can also specify whether or not variables related to the combustion model are treated as bounded.
To enable any of these beta features, select the pressure-based solver, select a second-order transient formulation, enable beta feature access (Introduction), and then respond appropriately to the prompts in the following text command:
solve → set →
second-order-time-options