What are the best practices and standards for CFD validation and verification in civil engineering?

1 What is CFD V&V?

CFD V&V is the process of assessing the uncertainty and error in CFD simulations by comparing them with experimental data, analytical solutions, or other reliable sources of information. Validation is the process of evaluating how well the CFD model represents the physical reality of the problem, while verification is the process of checking how well the numerical solution satisfies the mathematical model. Both validation and verification are essential for establishing the confidence and credibility of CFD results.

2 Why is CFD V&V important?

CFD V&V is important for several reasons. First, it helps to identify and quantify the sources and magnitudes of uncertainty and error in CFD simulations, such as modeling assumptions, numerical methods, grid resolution, boundary conditions, and input data. Second, it provides a basis for selecting and improving the appropriate CFD models and methods for a given problem and for estimating the accuracy and reliability of CFD results. Third, it enables the communication and documentation of the quality and limitations of CFD simulations to stakeholders, clients, regulators, and peers.

3 What are the best practices for CFD V&V?

The best practices for CFD V&V are based on the principles and guidelines established by various professional organizations, such as ASME, AIAA, and IAHR. It is essential to define the objectives, scope, and criteria of the CFD simulation and the V&V process before beginning the analysis. Additionally, it is important to use reliable experimental data or analytical solutions as reference cases for validation and verification. A systematic and comprehensive uncertainty and error analysis should be conducted for each CFD simulation, including sensitivity, grid convergence, and code verification studies. Furthermore, all documentation and reports for the V&V process and results should be transparent and traceable in accordance with standards and formats recommended by the professional organizations. Lastly, it is necessary to review and update the V&V process and results as new data, models, or methods become available or as the problem changes.

4 How to apply CFD V&V in civil engineering projects?

When applying CFD V&V in civil engineering projects, a careful planning, execution, and evaluation of the CFD simulation and the V&V process must be done, taking into account the project's specific characteristics, requirements, and challenges. To do this, you must define the problem statement, objectives, scope and criteria of the CFD simulation and the V&V process. It is also important to review literature and previous studies to identify relevant physical phenomena, models, methods and data for the simulation. You should then select and prepare experimental data or analytical solutions as reference cases for validation and verification. The CFD simulation should be performed with appropriate models, methods and software following best practices. The results should then be analyzed and evaluated using quantitative and qualitative measures of uncertainty and error. Lastly, document and report the simulation and results following best practices and standards for CFD V&V, communicating with stakeholders to highlight strengths, limitations, and implications of the CFD results.

5 What are the challenges and limitations of CFD V&V in civil engineering?

CFD V&V in civil engineering is not without its challenges and limitations. Complexity and variability of civil engineering problems, such as multiple scales, domains, phases, and interactions of fluid flow and heat transfer, can make it difficult to obtain experimental data or analytical solutions for validation and verification. Additionally, there is a trade-off between accuracy and efficiency of CFD models and methods, which can require high computational resources, time, and expertise. Finally, the lack of universal and consistent standards and criteria for CFD V&V in civil engineering can lead to ambiguity, inconsistency, and confusion among different users and applications.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?