Is there a best practice for the spatial discretization gradient options in Ansys Fluent?
The gradient of the solution variables are required in order to evaluate diffusive fluxes, velocity derivatives, and for higher-order discretization schemes by the solver.
The gradients of solution variables at cell centers can be determined using three approaches:
– Green-Gauss Cell-Based – Good, but solution may have false diffusion (smearing of the solution fields)
– Green-Gauss Node-Based – More accurate; minimizes false diffusion; (strongly recommended for tri/tet and hybrid meshes)
– Least-Squares Cell-Based – The default method. Less expensive to compute than Node-Based gradients. Slightly more expensive than Cell-Based gradients. However, exactly reconstruct linear field on highly skewed or distorted meshes (appropriate for any kind of meshes).