Prism Layer Total Thickness Calculator
Here’s a comprehensive table summarizing the key aspects of Prism Layer Total Thickness in CFD simulations:
| Aspect | Description |
|---|---|
| Definition | The overall thickness of the prism layer mesh, ideally covering the entire boundary layer13. |
| Purpose | To accurately capture near-wall flow behavior and resolve boundary layer effects3. |
| Calculation | Can be estimated using White’s (2006) equation for turbulent flow over a flat plate: δ ≈ 0.37x / (Re_x^0.2), where δ is the boundary layer thickness, x is the characteristic length, and Re_x is the Reynolds number based on x3. |
| Relationship to Boundary Layer | The prism layer total thickness should ideally match the boundary layer thickness3. |
| Number of Layers | Determined using a geometric progression relating total thickness (δ), first layer thickness (X), number of layers (m), and stretching factor (r)3. |
| First Layer Thickness | Depends on the target y+ value, which is related to the chosen turbulence model3. |
| Stretching Factor | Typically ranges from 1.05 to 1.2, directly specified by the user3. |
| Mesh Quality Considerations | Ensure smooth transitions between layers (ratio ≤ 1.3) and between the last prism layer and the primary mesh4. |
| Adjustment Method | Start with a coarse grid, run simulation, extract results, plot y+, then refine the grid accordingly and rerun4. |
| Software Implementation | In some CFD software, users may need to specify either growth ratio or first cell height, not both simultaneously5. |
| Visualization | Modern CFD software offers field functions to visualize prism layer thickness, first layer height, and layer numbers7. |
This table provides a concise overview of the key factors to consider when working with Prism Layer Total Thickness in CFD simulations. It covers the definition, purpose, calculation methods, and practical considerations for implementing and optimizing prism layers in your mesh.