Near-Wall Resolution

Accurate wall-bounded simulations depend on resolving the region close to solid surfaces. Near-wall resolution affects drag, pressure drop, separation, heat transfer, and wall shear.

Why It Matters

Wall-bounded flows contain steep velocity and temperature gradients near surfaces. If the mesh is too coarse near walls, results can show incorrect forces, pressure losses, heat-transfer rates, or separation behaviour.

y+ Guidance

The y+ value describes how fine the wall-adjacent mesh is relative to the local flow. Studio includes a y+ calculator to help choose near-wall settings from flow speed, length scale, fluid properties, and turbulence model.

Target

Typical Use

y+ around 1

Wall-resolved studies, detailed heat transfer, LES-like workflows, sensitive separation prediction.

y+ around 30

General RANS engineering workflows with wall functions.

y+ 30-300

Some high-Reynolds-number wall-function workflows where global trends are more important than local wall detail.

Tip

For most first-pass RANS simulations, start with the default near-wall settings and use the y+ calculator before committing to a final mesh.

Configuring Near-Wall Resolution

  1. Open the Mesh Settings tab.

  2. Select the mesh type and base resolution.

  3. Set the near-wall or boundary-layer controls.

  4. Use the y+ Calculator for the expected operating condition.

  5. Generate the mesh and review y+ and quality metrics in the Mesh Quality panel.

Structured and Unstructured Meshes

Both structured and unstructured meshing workflows include near-wall controls. The exact controls differ by mesh type, but the engineering goal is the same: place enough resolution near walls for the selected turbulence model and quantity of interest.

Practical Checks

  • Review wall-adjacent quality warnings before running.

  • Check y+ distribution, not only the average value.

  • Refine locally near leading edges, separation points, heat sources, and narrow gaps.

  • Keep final settings consistent across comparative design studies.

  • Perform a mesh sensitivity check for final reported results.