CFD models are always approximations of reality and include simplifications and assumptions that may lead to deviations. Since the underlying mathematical equations are often not exactly solvable, they require numerical methods. Responsibility for the quality of results lies with the user, who must ensure that the appropriate model is used for the given task. Solution verification by the user should ensure the consistency and stability of the calculation, as well as the achievement of expected effects.
The WTG Guideline M3 "Numerical Simulation of Wind Flows" provides a specific checklist for solution verification in Section 5.2:
Modeling
- Does the selected model capture the desired effects?
- Was the correct scale used?
- Is the investigation area sufficiently large? (see 4.1.3)
- Is the blockage ratio sufficiently low? (see 4.1.3)
- Are the boundary conditions correctly formulated?
- Are the input parameters sufficiently described (range, variability)?
Grid Quality
- Is the grid fine enough in critical areas?
- Is the grid's effect on the solution known?
- Does the grid work equally well for different inflow directions?
Numerical Parameters
- Has convergence of the desired target values been achieved?
- Is the time resolution fine enough for the expected phenomena?
Plausibility
- Does the flow proceed in the correct direction?
- Are the flow separation points plausible?
- Are the pressure and suction coefficients plausible?
- Are the wind speed fluctuations plausible?
- Is the distribution of turbulence parameters appropriate?
This list represents the minimum criteria for reviewing various aspects of a CFD solution and can be expanded as needed. For novel tasks, a more extensive review process is required, while for recurring questions or variant studies, the review scope can generally be reduced. -> Refer to the Dlubal technical article.