Design Competition Report Cougar Shadow Human Powered Vehicle Team Report Prepared by:

Washington State University Vancouver entered the 2007 HPVC with a reverse three wheel recumbent design. This vehicle had some good features. The 2008 team decided to make several improvements to the existing vehicle; some of which are: a new carbon-fiber fairing, simplified rear suspension, stronger front suspension, highly adjustable pedal position, and larger chain ring. The decisions to implement these changes were arrived at through the use of weighted rating matrices, expert advice from bicycle professionals, and mathematical analysis. Some of the initial choices were later changed due to further introspection following consul-tation with experienced advisers. In particular, the original plan to create a new frame with chrome moly tubing was eliminated when it was obvious that the manufacturability was difficult and our time would be better spent modifying the existing aluminum frame. Conceptual designs were made using SolidWorks parametric modeling software. COSMOS FloWorks was used to assess the aero-dynamic characteristics of our fairing design. Finite Element Analysis of the frame and suspension components was carried out with COSMOS and in some cases with ANSYS. Stress testing with an Instron machine was used to verify the critical components and to check the strength of our welds. Two iterations of our fairing design were also tested in a water tunnel to visualize the fluid flow in order to reduce the turbulence and thereby decreasing the drag. The resulting vehicle performance is expected to be a significant improvement over the existing design. Construction is currently under way and tests of the final product will prove our design. We will make modifications to correct any problems encountered an