Skyscraper shapes and wind forces
The materials required for this science fair project:
- An high-velocity fan with 5 fan speeds. It would be best if you are able to find an industrial fan
- 4 pieces of polystyrene foam measuring 200m x 200mm x 500mm
- 4 pieces of plywood measuring 600mm x 600mm x 1500mm
- A hammer
- 1 box of nails
- A ruler
- A pen-knife
- 4 boxes of playdough
1. For this science fair project, the independent variable is the shape of the buildings, i.e. with a rectangular, triangular, circular or oval cross-section. The dependent variable is the velocity of the wind that the model building can withstand before it collapses. This is determined by gradually increasing wind speed and observing the model buildings. The constants (control variables) are the size of the model buildings, the amount of playdough used to mount the building and the size of the wind tunnel.
2. Using 4 pieces of plywood, nails and a hammer, build a square wind tunnel measuring 600mm x 600mm x 1500mm. Position the industrial fan at the entrance of the wind tunnel.
3. Next, using the paper knife, cut the 4 pieces of polystyrene foam into model buildings with a rectangular, triangular, circular and oval cross-section. The height of the 4 buildings should be 500mm and their cross sectional area should be the same.
4. Mount the 1st building to be tested on the opposite side of the wind tunnel, away from the fan. Use one box of playdough to mount the model building onto the floor of the wind tunnel. Increase the speed of the industrial fan gradually and observe at which speed the model building collapses. Record your observations in the table below.
5. Procedure 4 is repeated with the other 3 model buildings and the results are recorded in the table below.
Basic safety requirements. Ensure that you handle the fan with care to avoid accidents.