Mesh Issues

Is the mesh quality satisfactory and could improving the mesh in some way help convergence?

• In particular, is the mesh able to resolve the variations of the flow? This can affect the convergence of the solution, and also the accuracy of the resulting solutions. Quantities to look at are the mesh density, grading, orthogonality, smoothness, skewness and cell aspect ratio
  
  
• Are there large residuals in a localised area of the flow, which may be inhibiting convergence? Local mesh refinement or mesh adaptation might help in this circumstance.
  
  
• It can help to have the mesh aligned with the flow. This can improve accuracy and improve convergence.