BCIT Physics Department

Demonstration Manual

Fluid Mechanics

DF07 - Roof Model / Bernoulli's Principle


- To demonstrate that air flow (wind) over a roof can cause the roof to lift off of the building.


Method A:

Set up the apparatus as shown in the picture. Turn on the air source and direct the air flow over first the peak roof model and then the rounded roof model.

The air flow should start at the hinged edge. With some experimentation one can show that the rounded roof model has a slightly greater tendancy to lift. (less turbulance for the rounded model).

Note that the difference is not marked, the demonstrator needs to sharpen their technique before making the class presentation. The strength of the air flow can be modified by increasing the distance between the end of the hose and the models.

Further, if the lab supply with flexible hose is used, pinching the end of the hose enhances the lifting effect.

youtube logo   Watch a Bernoulli's Principle Demo: Paper on Table video demonstration on Youtube

- Video Created at Utah State University by Professor Boyd F. Edwards and assistants.