Bolund Island#
1. Project Description#
The objective of this project is to reproduce the wind flow properties over the Bolund Island, as measured on-site by [1]. One convective time scale is defined as \(CTS = H / U_H\), where \(H =\) 12 meters is the nominal height of the island.
The island positioned at the computational domain has the geometry:
And probes are positioned over the island for velocity measurement:
The wind directions chosen to be simulated were:
Wind direction |
270.0 \(^\circ\) |
255.0 \(^\circ\) |
239.0 \(^\circ\) |
2. Simulation Setup#
The Synthetic Eddy Method (SEM) boundary condition is applied at the inlet of the computational domain. Since it is a category 0 terrain, no fins were necessary to be distributed over the floor.
The domain of interest is at resolution level \(lvl\,4\) of the digital wind tunnel:
A 1:2 refinement ratio is estabilished between levels, and the simulation parameters at grid \(lvl\,4\) were:
\(\boldsymbol{\Delta x/B}\) (spatial resolution) |
6.25e-02 |
\(\boldsymbol{\Delta t/CTS}\) (temporal resolution) |
3.17e-03 |
exports/\(\boldsymbol{CTS}\) (pressure acquisition frequency) |
1.00e+01 |
\(\boldsymbol{T/CTS}\) (statistical sample size) |
4.55e+02 |
\(\boldsymbol{Re_{H}=U_{H}H/\nu}\) |
3.80e+04 |
The equivalent parameters in full scale are:
\(\boldsymbol{\Delta x[m]}\) |
0.75 |
\(\boldsymbol{\Delta t[ms]}\) |
3.30 |
\(\boldsymbol{f[Hz]}\) |
9.59 |
\(\boldsymbol{T[s]}\) |
475.00 |
The computational resources required were:
Device |
NVIDIA RTX A5500 |
NVIDIA RTX A5500 |
NVIDIA RTX A5500 |
Wind direction |
270.0 \(^\circ\) |
255.0 \(^\circ\) |
239.0 \(^\circ\) |
Node count (million) |
103.62 |
107.29 |
107.31 |
Allocated memory (Gb) |
13.36 |
13.82 |
13.82 |
Ellapsed time (h) |
6.33 |
6.45 |
6.29 |
3. Inflow#
The inflow is taken from a measurement at M0.
4. Results: Velocity and Turbulence Profiles#
Mean velocity and turbulence intensity profiles are measuread at different points for each wind direction chosen and compared against experimental data.
Mean Longitudinal Velocity#
Execution Notes#
Execution Date (YYYY-MM-DD) |
2024-11-23 |
Solver Version |
1.6.2 |
Changelog#
30 Jan 2025: Updated results.
26 April 2024: Uploaded point comparisons, simulations executed with Nassu release v1.5.4.