Sig WindE/Validation Cases

The aim of this page is to hold validation cases for ABL (Atmospheric Boundary Layer) flows that are of interest to anybody starting to model in OF. The page will hold links to databases and articles describing experiments, and also instructions on how to make meshes and set boundary conditions that give fair results, hopefully the end result will be complete cases.

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(1) Flow over Isolated 2D Hill Experiments by Khurshudyan et al.[1]

This is a wind tunnel experiment with a 2D hill of several aspect ratios, named also RUSHIL experiment. The latest comparison to it was published by Kasmi and Mason 2010 [2]

Creating the STL surface The shape of the 2D hill is an analytical function described in [3] as:

$x = \frac{1}{2} \xi \left[ 1+\frac{a^2}{\xi^2+m^2(a^2- \xi^2)} \right]$

$z = \frac{1}{2} m \sqrt{a^2-\xi^2} \cdot \left[ 1- \frac{a^2}{\xi^2+m^2(a^2- \xi^2)} \right]$

where $m = \frac{h}{a}+\sqrt{\frac{h}{a}+1}$ and h is the height of the hill ($h = 0.117 [m]$) and a is the length of the hill. $\xi$ is a parameter that changes from 0 to a. The aspect ratio of the hill is 3, 5 and 8.

The experimental setting was:

logarithmic inlet profile with $z_0=0.157 \cdot 10^-3 [m]$, $u_{*} = 0.178 \left[ \frac{m}{s}\right]$ which gives for instance $U_\infty = 3.9 \left[ \frac{m}{s} \right]$ at $z = 1 [m]$

"1" The Profile was created with the desired discretization in a spreadsheet program. Column x (1st column) was the width of the hill (arbitrary width), 2nd column is x and the third z. Finally the 3 columns where exported as a csv file RUSHIL_8.csv.

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