High resolution CFD grid covering the complex site of Perdigão in Portugal.

What CFD resolution?

Friday 13 May 16

CFD modellers are often asked: “What grid resolution did you use?” The question is important because CFD simulations performed on coarse grids may cause significant modelling errors, making them useless for wind resource assessment. A new CFD study quantifies the errors and raises a new question: “What order of discretization scheme did you use?”

In a new DTU report, 400 CFD simulations of the Perdigão site in Portugal highlights the numerical requirements for microscale CFD modelling applied for wind resource assessments. In the report, the influence of spatial grid resolution and order of discretization scheme were investigated; and the report is not for the faint-hearted. Low-order discretization schemes cause errors comparable to those made by doubling or even quadrupling the grid resolution. Using first-order schemes instead of third-order increased the error by more than 500%. The numerical error of WAsP CFD is also investigated.

If you dare, the full report can be found here.

This work is part of the New European Wind Atlas project, see euwindatlas.eu
16 JANUARY 2018