'Antenna tower flow analysis' simulation project by Ali_Arafat


#1

I created a new simulation project called 'Antenna tower flow analysis':

Air Flow Analysis of an Antenna tower


More of my public projects can be found here.


#2

Overview

In this sample project, aerodynamic analysis of an ‘Antenna Tower’ is performed. The purpose was to study qualitatively the flow field around the umbrella shaped Antenna configuration with 6 antenna parts.

Two types of analysis were carried out. First, a ‘Steady State’ of the full configuration at wind speeds of around 50 kph or about 13 m/s. The flow direction in both cases was in the positive-X direction.

Geometry for Steady analysis is shown below:


.

Second, a ‘Transient’ analysis of only a single antenna part was done to see if any vortex shedding behavior is observed .
Geometry for Transient analysis is shown below:

The geometries were meshed using the ‘SnappyHexMesh’ on the SimScale platform.
Both analysis, are done with turbulence modelling using ’ K-Omega SST’ model. Also, where applicable the problem was simplified by using symmetry conditions in the domain.

The Results for the Steady State analysis are shown below:

The velocity field around antenna configuration:

Steady State velocity results, Top View:

Steady State velocity results, Close up:

Steady State velocity results, Section View:

Steady State velocity results, Flow visualization with streamlines:


.

Steady State pressure results :



.
.

Transient Analysis:

The Results for the Transient analysis are shown below:

The transient case was run at 12m/s wind velocity for a simulation time of 1.4 sec on a coarse mesh. At these flow conditions, no vortex shedding behavior was observed and the flow remained steady.

The aerodynamic pressure force on the antenna therefore remained constant and is shown in the results below. The force computation was done by a ‘Result Control’ item on SimScale platform and can be viewed in the result plots and log.

Transient velocity results at time 1.4sec, Top view:

Transient velocity results, side view:

Transient case, pressure force on antenna:

Force and Moment plot:

.

This sample simulation shows how a steady and transient flow analysis can be carried out to determine the aerodynamic loads on such structures. A more detailed analysis can then be carried out to investigate the problem further.