MESH / 004
Prism Layer Calculator
Turn first-layer height into a complete prism stack—or work backwards from the total thickness you need. Useful after the y+ calculation when defining near-wall mesh growth.
First-cell height is only the start of the wall-normal mesh.
A good near-wall strategy also needs enough total thickness and controlled growth. The prism stack should transition smoothly into the core mesh while covering the wall-normal gradients that matter to the problem.
Estimate the first layer. Use the y+ calculator or a previous solved case.
Choose a reasonable growth rate. Avoid abrupt jumps purely to reduce cell count.
Check total thickness. The stack should reach beyond the steep near-wall region relevant to your model.
Verify the solved field. Inspect y+, velocity/temperature gradients and prism quality after solving.
A calculated prism stack still has to survive the real geometry.
Narrow gaps, curvature, sharp corners and surface resolution can force layers to shrink, merge or collapse even when the stack mathematics is correct.