Open this dialog by clicking the 1st cell height calc icon on the BL parameters subpanel.
This utility helps you estimate the proper first cell height (first layer thickness) for the boundary layer generation, based on the flow characteristics and fluid properties.
The entry fields on this dialog are actually settings for the Calculate first layer thickness button. Once you supply the required data, clicking this button causes the dialog to automatically calculate and suggest an appropriate thickness.
• | Bulk velocity (meters/sec): an average flow velocity |
• | Length scale (meters): A characteristic length of your model, for example in case of a tube, it can be the diameter of the tube |
• | Kinematic viscosity (meters^2/sec): the viscosity of the fluid. |
• | y+ value: the y+ value required by the turbulence model |
• | Calculation Schemes: Choose the scheme most appropriate to your problem. |
Once all of these qualities are specified, clicking Calculate first layer thickness produces a suggested thickness. You can either Accept this value, in which case the window closes and the value is automatically placed into the First layer thickness field of the CFD Tetramesh panel, or you can click Close to close the window without accepting the suggested value.