Interpretation of Validation Results Following ASME V&V20-2009

Abstract

Suggestions are made for modification and extension of the methodology and interpretations of ASME V&V 20-2009, Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer. A more conservative aggregation of numerical uncertainty into the total validation uncertainty is recommended. A precise provisional demarcation for accepting the validation comparison error as an estimate of model error is proposed. For the situation where the validation exercise results in large total validation uncertainty, a more easily evaluated estimated bound on model error is recommended. Explicit distinctions between quality of the model and quality of the validation exercise are discussed. Extending the domain of validation for applications is treated by interpolating/extrapolating model error and total validation uncertainty, and adding uncertainty from the new simulation at the application point. Model form uncertainty and epistemic uncertainties in general, while sometimes important in model applications, are argued to not be important issues in validation.