Materials ai 3-speed fan ai 6-foot-long table (or longer) ai chair ai drop cloth ai sugar (5-pound bag); very fine sand can be substituted ai small ... The wind produced by the fan has a aquot;spinaquot; to it because of the fan blades. ... Clear plastic wrap (for the side a#39;windowsa#39;) 7. Sand collection tray (such as a kitty litter box) 8. Dark-colored posterboard Construction: Figure 9.1 shows the set-up for the wind tunnel.