UNCERTAINTIES AND CFD CODE VALIDATION

A new approach to computational fluid dynamics code validation is deve loped that gives proper consideration to experimental and simulation u ncertainties. The comparison error is defined as the difference betwee n the data and simulation values and represents the combination of all errors. The validation uncertainty is defined as the combination of t he uncertainties in the experimental data and the portion of the uncer tainties in the CFD prediction that can be estimated. This validation uncertainty sets the level at which validation can be achieved. The cr iterion for validation is that the magnitude of the comparison error m ust be less than the validation uncertainty. If validation is not acco mplished, the magnitude and sign of the comparison error can be used t o improve the mathematical modeling. Consideration is given to validat ion procedures for a single code, multiple codes and/or models, and pr edictions of trends. Example results of verification/validation are pr esented for a single computational fluid dynamics code and for a compa rison of multiple turbulence models. The results demonstrate the usefu lness of the proposed validation strategy. This new approach for valid ation should be useful in guiding future developments in computational fluid dynamics through validation studies and in the transition of co mputational fluid dynamics codes to design.