Verification and Validation in Computational Fluid Dynamics
Handbook of Fluid Dynamics, Second Edition
Verification and validation (V&V) are the primary means to assess accuracy and reliability in computational simulations. This paper presents an extensive review of the literature in V&V in computational fluid dynamics (CFD), discusses methods and procedures for assessing V&V, and develops a number of extensions to existing ideas. The review of the development of V&V terminology and methodology points out the contributions from members of the operations research, statistics, and CFD communities.
... nd CFD communities. Fundamental issues in V&V are addressed, such as code verification versus solution verification, model validation versus solution validation, the distinction between error and uncertainty, conceptual sources of error and uncertainty, and the relationship between validation and prediction. The fundamental strategy of verification is the identification and quantification of errors in the computational model and its solution. In verification activities, the accuracy of a computational solution is primarily measured relative to two types of highly accurate solutions: analytical solutions and highly accurate numerical solutions. Methods for determining the accuracy of numerical solutions are presented and the importance of software testing during verification activities is emphasized. The fundamental strategy of Verification: The process of evaluating the products of a software development phase to provide assurance that they meet the requirements defined for them by the previous phase. This IEEE definition is quite general and it is referential; that is, the value of the definition is related to the definition of "requirements defined for them by the previous phase." Because those requirements are not stated in the definition, the definition does not contribute much to the intuitive understanding of verification or to the development of specific methods for verification. While the definition clearly includes a requirement for the consistency of products (e.g., computer programming) from one phase to another, the definition does not contain a specific requirement for correctness or accuracy. At the same time, IEEE defined validation as follows [167, 168] : Validation: The process of testing a computer program and evaluating the results to ensure compliance with specific requirements.