Validation problems in computational fluid mechanics

Recent developments in Computational Fluid Dynamics (CFD) increased interest in quantifying quality of the numerical models. One of the necessary steps is the so-called code validation procedure, an assessmentof a numerical simulation by comparisons between simulation results and laboratory measurements. The focus of the present review is application of modern full ?eld experimental techniques, mostly based on thedigital image analysis, in validating numerical solutions of complex flow configurations. Each validationprocedure opens new issues of quantifying its outcome to find directions for model updating, limits ofcomputer simulation quality, and to perform uncertainty quantification.