Because of the necessity to model many of the unresolved details of technical flows, it is necessary to assess the accuracy of the CFD method with the help of experimental data. Experiments are required for the following tasks and purposes:
Verification of model implementation
Validation and calibration of statistical models
Demonstration of model capabilities.
There is no philosophical difference between the different types of test cases. The same test case can be used for the different phases of model development, implementation, validation, and application, depending on the status of the model and the suitability of the data.