Quality Criteria for Large Eddy Simulation - Turbulence Mechanics ...

CHAPTER 2. LITERATURE REVIEW 14
Gresho and Taylor, 1994]. This topic has been the subject of debate for
several symposia of the ASME, resulting in a series of special publications
[Celik and Freitas, 1990, Celik et al., 1993, Johnson and Hughes, 1995]. Most
of these policy statements dictate the requirements imperative for the accep-
tance of computational results. These requirements typically include, among
other less stringent criteria, the following.
1. A precise description of the basic features of the numerical method,
including a formal assessment of the order of the truncation errors in
the individual terms in the governing equations.
2. An accuracy of at least the second order in space for nodes in the inte-
rior of the computational grid, in order to avoid the devastating effect
of numerical diffusion on the solution accuracy in first order methods.
3. An assessment of the inherent or explicit artificial viscosity or diffusivity
and an explanation of the efforts to minimize the same.
4. A systematic evaluation of the truncation error and accuracy and the
confirmation of grid independence and convergence of the solution by
presenting solutions over a range of significantly different grid resolu-
tions.
5. Use of error estimates based on methods such as the Richardson ex-
trapolation or techniques in adaptive grid methods.
6. A precise explanation of stopping criteria and estimation of correspond-
ing convergence error for iterative calculations.
7. An assessment and minimization of phase errors in transient calcula-
tions.