The issue of numerical uncertainty

Computational fluid dynamics (CFD) computer codes have become an integral part of the analysis and scientific investigation of complex, engineering flow systems. Unfortunately, inherent in the solutions from simulations performed with these computer codes is error or uncertainty in the results. The issue of numerical uncertainty addresses the development of methods to define the magnitude of error or to bound the error in a given simulation. This paper reviews the status of methods for evaluation of numerical uncertainty, and provides a direction for the effective use of some techniques in estimating uncertainty in a simulation.