Journal of Applied Mathematics
Volume 2012 (2012), Article ID 268371, 12 pages
Research Article

A Numerical Study on Flow around Nonuniform Porous Fences

1Department of Soil and Water Conservation, National Chung Hsing University, Taichung 40227, Taiwan
2Sinotech Engineering Consultants, Ltd., 12th Floor, 171 Nanking E. Road. Section 5, Taipei 10570, Taiwan

Received 15 February 2012; Accepted 27 May 2012

Academic Editor: Shuyu Sun

Copyright © 2012 Long-Ming Huang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The effects of a porous fence with a nonuniform porosity on flow fields are investigated numerically. First, an experiment with a non-uniform porous fence located in a wind tunnel is performed to obtain a reference data set. Then, a numerical model that utilizes the finite volume scheme with a weakly compressible-flow method to solve the continuity and momentum equations is developed. The numerical simulation is compared to experimental measurements for validation purposes. As a result, the numerical predictions show good agreements with the experimental data. Finally, the numerical investigations of the flow fields around porous fences with various combinations of upper and lower fence porosity are also presented. When the upper porosity is greater than the lower porosity, the Protection Index PI0.1, PI0.3 and PI0.5, representing the adverse sheltering effect, decreases compared to that of the uniform porous fence. When the upper porosity is less than the lower porosity, the PI0.5 increases and the variations of the PI0.1 and PI0.3, depend on the upper porosity, compared to that of the uniform porous fence. The results show that the porous fence with the upper fence porosity εU=0% and the lower fence porosity εL=30% gives the best sheltering effect among the porous fences in this study.