For a pre-defined body-fitted mesh (including meshes created using the Sector Mesh Generator), Remeshing Controls are available under the Mesh Controls node. These are used to control the mesh movement for internal combustion engine simulations in particular. For static meshes, such as for a spray-bomb simulation, no mesh controls are necessary.

During piston motion in an IC Engine simulation, the mesh is compressed and the boundary region associated with the piston moves according to the engine crank rotation. To make sure that the mesh retains good grid quality and an accurate solution results, an algorithm within Ansys Forte automatically and dynamically controls the mesh movement and rearrangement during the simulation. The algorithms employed during mesh movement modify both the mesh boundary and interior at a given time step. Specifically for in-cylinder simulations with piston motion, there are several parameters that control the mesh-motion behavior. While default values of these parameters are usually sufficient, they may be modified to achieve better cell quality for a given geometry. The control parameters for IC Engine simulations are listed below with a brief description of each parameter.

Min. Cell Height: Threshold for minimum cell height during mesh rezoning and smoothing.

Min. Cell Layers in Squish Region: Effectively sets the number of cell layers in the squish layer at top dead center.

Cell Expansion Ratio from Piston: Ratio by which cell heights expand from the piston. A larger number will decrease cell heights closer to the piston.

Cell Expansion Ratio from Head: Ratio by which cell heights expand from the head. A larger number will decrease cell heights closer to the head.

Max. Bowl Excursion: Maximum fraction of the squish region that bowl vertices are allowed to occupy in a smoothing iteration.