Geometric shapes all have different drag effects in a flowing air stream. The drag on an object due to air velocity varies with the surface area, roundness and surface finish. In this experiment, drag values and effects of drag on various objects were observed and recorded. The objects that were tested consisted of : cone, triangle, rectangle, cube, egg, cylinder, convex cylinder, pyramid, stepped cone and sphere.

1. Ten shapes (shown in figure links below) were built from hardwood to the specified dimensions. The shapes were then sanded with 100 grit, 150 grit and 220 grit sand paper to attain the desired finish. A 1/4" was drilled in the center of the specimens to insert the Tinnerman Tee Nut (1/4" - 20UNC x 9/16" long) for attaching the specimen to the sting mount. The dimensions were checked and recorded for easy access during the experiment.
2. After the experiment was set up, the object was placed on the sting mount in the wind tunnel. The wind tunnel was secured and turned on. Drag was recorded at roughly 15 different velocities ranging from 10 meters/seconds to 56 meters/ seconds. This process was repeated for the remaining 9 objects.

1. From the drawing determine the frontal area for each object.
2. From the available table, calculate the Reynolds Number and Drag Coefficient for each object.
3. Plot Drag versus Velocity for each geometry.
4. Plot CD versus Re for each geometry.
5. Compare with expected values and discuss.