Research Papers

Reduced Rough-Surface Parametrization for Use With the Discrete-Element Model

[+] Author and Article Information
Stephen T. McClain

Mechanical Engineering Department, Baylor University, One Bear Place, No. 97356, Baylor, TX 76796-7356stepheṉmcclain@baylor.edu

Jason M. Brown

Department of Mechanical Engineering, The University of Alabama at Birmingham, 1530 3rd Avenue South, BEC 257, Birmingham, AL 35294-4461jmbrown@rockwellcollins.com

J. Turbomach 131(2), 021020 (Feb 03, 2009) (12 pages) doi:10.1115/1.2952379 History: Received August 28, 2007; Revised October 22, 2007; Published February 03, 2009

The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element diameter distribution as a function of height to predict the drag and heat transfer of flow over a randomly rough surface. The requirement for a roughness-element diameter distribution at each height from the reference elevation has hindered the usefulness of the discrete-element model and inhibited its incorporation into a computational fluid dynamics (CFD) solver. To incorporate the discrete-element model into a CFD solver and to enable the discrete-element model to become a more useful engineering tool, the randomly rough surface characterization must be simplified. Methods for determining characteristic diameters for drag and heat transfer using complete three-dimensional surface measurements are presented. Drag and heat transfer predictions made using the model simplifications are compared to predictions made using the complete surface characterization and to experimental measurements for two randomly rough surfaces. Methods to use statistical surface information, as opposed to the complete three-dimensional surface measurements, to evaluate the characteristic dimensions of the roughness are also explored.

Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 3

Blockage fraction of the deposit and erosion surfaces compared to error function approximation

Grahic Jump Location
Figure 4

Characteristic dimensions of the deposit surface

Grahic Jump Location
Figure 5

Characteristic dimensions of the erosion surface

Grahic Jump Location
Figure 6

Ratio of characteristic diameters versus dimensionless height

Grahic Jump Location
Figure 7

The variation in average shape factor versus height

Grahic Jump Location
Figure 1

The discrete-element roughness model control volume schematic

Grahic Jump Location
Figure 2

A rough surface (a) and its computational DEM representation (b)




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In