Verification and Validation in CFD Using an Adaptive Finite-Element Method

This paper presents adaptive finite-element methods as a means of achieving verification of codes simulations (obtaining numerical solutions with controlled accuracy). Validation of these grid-independent solutions is then performed by comparing predictions to measurements. We adopt the standard accepted definitions of verification validation (AIAA 1998; Roache 1998). Mesh adaptation is used to perform the systematic rigorous grid-refinement studies required for both verification validation in CFD. This ensures that discrepancies observed between predictions measurements are due to deficiencies in the mathematical model of the flow. Issues in verification validation are discussed. The paper presents examples of code verification by the method of manufactured solution. Examples of successful unsuccessful validation show that agreement with experiment is achieved only with a good mathematical model of the flow physics combined with accurate numerical solutions of the differential equations. The paper emphasises good CFD practice to systematically achieve verification so that validation studies are always performed on solid grounds.