For a school science project I am supposed to design an experimental process that utilizes the wind tunnel my school owns. I've built four small model towers out of wood - one a triangular prism, one a rectangular prism, one a cylinder, and one a pyramid - that all have the same height and base width. The idea is to see which shape of tower will stand up the best against wind. The problem is, once I put the towers into the wind tunnel, I have no idea how to measure which one has the best design for resisting wind force. I need to have numerical data that I can graph and analyze. I've tried a pretty terrible experiment involving measuring how much a tower will tip when sunken into a bed of clay, but that didn't work well with the powerful wind tunnel. I could try to improve this idea, possibly, but I don't know how. Anybody have any ideas? I'm not looking for a very specific thing, like data or complex equations or anything, just some ideas for what dependent variable I can measure and how.