## Chapter 4: Remeshing Guide

Periodic remeshing is an important part of running analyses that involve significant mesh deformation. Remeshing is often required simply to maintain acceptable mesh quality, as described in Discretization Errors in the CFX-Solver Theory Guide and Measures of Mesh Quality in the CFX-Solver Modeling Guide.

A schematic illustrating the integration of remeshing into the general simulation workflow is shown in the figure below.

Figure 4.1: Integration of a Remeshing Loop into the General Simulation Workflow

As shown in Figure 4.1: Integration of a Remeshing Loop into the General Simulation Workflow, in addition to the Preprocessing and Solution steps of the standard simulation workflow, the remeshing loop includes three additional steps:

- Data Extraction

- Geometry Modification

- Mesh Recreation.

In the context of remeshing, those steps are responsible for completing the following sub-steps;

- Data Extraction: Extract any data needed to guide geometry modifications and mesh re-creation from the most recent analysis results and monitor point values.

- Geometry Re-Creation: Update the analysis’ geometry so that it conforms to that of the most recent analysis results (that is, account for mesh deformation).

- Mesh Re-Creation: Generate new mesh(es) that correspond to the updated geometry.

- Preprocessing: Insert the new mesh(es) into the analysis definition, and generate an updated CFX-Solver Input File.

- Solution: Interpolate the previously generated analysis results onto the new mesh, re-partition the mesh if a parallel run mode is selected, and continue the solution process.

As described in Remeshing Tab in the CFX-Pre User's Guide, there are two options available for remeshing: User Defined and ICEM CFD Replay. As outlined in the discussions that follow, the Preprocessing and Solution steps (and their respective sub-steps) are automatically executed for both remeshing options. Although the remaining steps are automatically executed for the ICEM CFD Replay remeshing option, they become the responsibility of a user defined external command for the User Defined remeshing option.

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