In validation using wind tunnel models, the numerical simulation does not necessarily need to replicate the exact scale and boundary conditions of the wind tunnel. Due to the sensitivity of incompressible flows to the blockage ratio and potential leaks in wind tunnels, the dimensions, as well as the upstream and downstream lengths, should be adjusted to the computational method, especially in the case of open wind tunnels.
Complex boundary layer models are often difficult to scale to wind tunnel proportions. Therefore, for a valid transfer to full-scale conditions, calculations should also be performed at the original scale, which should yield similar results or show Reynolds number effects.
For validation, equivalent boundary conditions as in the wind tunnel test should be used, with deviations documented. Suitable measurement data from multiple wind tunnel tests with varying conditions (e.g., changing wind directions) should be used. For geometries without prior experience, it is advisable to first recalculate various known geometries.
When using proprietary measurements, detailed information about the wind tunnel, model dimensions, boundary conditions, as well as measurement results and positions should be provided. An example of such a preparation can be found in Section 9. Graphical representations alone are usually not sufficient.
Ideally, data from wind tunnel tests and numerical simulations should be freely accessible to third parties. For comparison, a sufficient number of points evenly distributed over the geometry should be selected.