PURPOSE: To show air flow around different objects.

DESCRIPTION: Dry ice is dropped into a container of water to produce visible air flow in the wind tunnel, which is then projected using an overhead projector. Various objects can be placed in the wind tunnel, and the air flow past the objects observed. The photographs below show a level airplane wing, an airplane wing with a small angle of attack, and a triangular object with the narrow point positioned into the wind.

SUGGESTIONS: Actual projected images have better visibility than those shown in the photographs.

REFERENCES: (PIRA 2C40.10) See Demonstration Reference File for further discussion of this apparatus.

EQUIPMENT: Wind tunnel, chamber with blower, dry ice and water container, stopper with hoses, various objects (airplane wing, circle, triangle, square).

SETUP TIME: 20 min. (Dry ice available from Chemistry Department)