CaltechAUTHORS
  A Caltech Library Service

Explicit filtering to obtain grid-spacing-independent and discretization-order-independent large-eddy simulation of two-phase volumetrically dilute flow with evaporation

Radhakrishnan, Senthilkumaran and Bellan, Josette (2013) Explicit filtering to obtain grid-spacing-independent and discretization-order-independent large-eddy simulation of two-phase volumetrically dilute flow with evaporation. Journal of Fluid Mechanics, 719 . pp. 230-267. ISSN 0022-1120. http://resolver.caltech.edu/CaltechAUTHORS:20130319-150030156

[img]
Preview
PDF - Published Version
See Usage Policy.

1725Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20130319-150030156

Abstract

Predictions from conventional large-eddy simulation (LES) are known to be grid-spacing and spatial-discretization-order dependent. In a previous article (Radhakrishnan & Bellan, J. Fluid Mech., vol. 697, 2012a, pp. 399–435), we reformulated LES for compressible single-phase flow by explicitly filtering the nonlinear terms in the governing equations so as to render the solution grid-spacing and discretization-order independent. Having shown in Radhakrishnan & Bellan (2012a) that the reformulated LES, which we call EFLES, yields grid-spacing-independent and discretization-order-independent solutions for compressible single-phase flow, we explore here the potential of EFLES for evaporating two-phase flow where the small scales have an additional origin compared to single-phase flow. Thus, we created a database through direct numerical simulation (DNS) that when filtered serves as a template for comparisons with both conventional LES and EFLES. Both conventional LES and EFLES are conducted with two gas-phase SGS models; the drop-field SGS model is the same in all these simulations. For EFLES, we also compared simulations performed with the same SGS model for the gas phase but two different drop-field SGS models. Moreover, to elucidate the influence of explicit filtering versus gas-phase SGS modelling, EFLES with two drop-field SGS models but no gas-phase SGS models were conducted. The results from all these simulations were compared to those from DNS and from the filtered DNS (FDNS). Similar to the single-phase flow findings, the conventional LES method yields solutions which are both grid-spacing and spatial-discretization-order dependent. The EFLES solutions are found to be grid-spacing independent for sufficiently large filter-width to grid-spacing ratio, although for the highest discretization order this ratio is larger in the two-phase flow compared to the single-phase flow. For a sufficiently fine grid, the results are also discretization-order independent. The absence of a gas-phase SGS model leads to build-up of energy near the filter cut-off indicating that while explicit filtering removes energy above the filter width, it does not provide the correct dissipation at the scales smaller than this width. A wider viewpoint leads to the conclusion that although the minimum filter-width to grid-spacing ratio necessary to obtain the unique grid-independent solution might be different for various discretization-order schemes, the grid-independent solution thus obtained is also discretization-order independent.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1017/jfm.2013.3DOIUNSPECIFIED
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8834760PublisherUNSPECIFIED
Additional Information:© 2013 Cambridge University Press. Received 16 February 2012; revised 16 October 2012; accepted 21 December 2012; first published online 19 February 2013. This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology and sponsored by the National Aeronautics and Space Administration (NASA) under the Fundamental Aeronautics Program, Subsonic Wing Program from NASA Glenn Research Center with Drs D. Bulzan and N.-S. Liu serving as program monitors and by the NASA Exploration Systems Mission Directorate/Advanced Capabilities Division under the LASER program. The computational resources were provided by the JPL Supercomputing Center and by the NASA AMES Supercomputing Center.
Funders:
Funding AgencyGrant Number
NASA Glenn Research Center UNSPECIFIED
NASA Exploration Systems Mission DirectorateUNSPECIFIED
Subject Keywords:multiphase and particle-laden flows; turbulence modelling; turbulence simulation
Record Number:CaltechAUTHORS:20130319-150030156
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20130319-150030156
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:37569
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:20 Mar 2013 16:39
Last Modified:29 Mar 2014 03:39

Repository Staff Only: item control page