skip to main content

Title: A procedure for the estimation of the numerical uncertainty of CFD calculations based on grid refinement studies

This paper offers a procedure for the estimation of the numerical uncertainty of any integral or local flow quantity as a result of a fluid flow computation; the procedure requires solutions on systematically refined grids. The error is estimated with power series expansions as a function of the typical cell size. These expansions, of which four types are used, are fitted to the data in the least-squares sense. The selection of the best error estimate is based on the standard deviation of the fits. The error estimate is converted into an uncertainty with a safety factor that depends on the observed order of grid convergence and on the standard deviation of the fit. For well-behaved data sets, i.e. monotonic convergence with the expected observed order of grid convergence and no scatter in the data, the method reduces to the well known Grid Convergence Index. Examples of application of the procedure are included. - Highlights: • Estimation of the numerical uncertainty of any integral or local flow quantity. • Least squares fits to power series expansions to handle noisy data. • Excellent results obtained for manufactured solutions. • Consistent results obtained for practical CFD calculations. • Reduces to the well knownmore » Grid Convergence Index for well-behaved data sets.« less
Authors:
 [1] ;  [2]
  1. Instituto Superior Técnico, Department of Mechanical Engineering, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)
  2. Maritime Research Institute Netherlands, PO Box 28 6700 AA, Wageningen (Netherlands)
Publication Date:
OSTI Identifier:
22314855
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Computational Physics; Journal Volume: 262; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CALCULATION METHODS; COMPUTERIZED SIMULATION; CONVERGENCE; ERRORS; FLUID FLOW; FLUID MECHANICS; INTEGRALS; LEAST SQUARE FIT; MATHEMATICAL SOLUTIONS; POWER SERIES