Modern society depends too heavily on unsustainable resources like fossil fuels. Decreasing consumption of fossil fuels increases economic stability and offers a prolonged life of the planet for generations to come. In order to promote innovation in vehicle efficiency, the Society of Automotive Engineers (SAE) holds an annual competition held June 4th, 2015 in Marshall, Michigan. The Supermileage competition provides engineering and technology students with a challenging design project that involves the development and construction of a single-person, fuel-efficient vehicle powered by a small four-cycle engine. The overall goal is to build the most efficient vehicle possible and increase public awareness of fuel economy. Team Gasbusters, the University of Nevada Supermileage Vehicle Club, will be tasked with this challenge. Team Gasbusters will be constructing an entire Supermileage vehicle from the ground up. The vehicle will be designed within specified SAE standards with a goal of achieving over 800 miles per gallon
Team Gasbusters’ Videos:
The University of Nevada, Reno is returning in 2015 to compete in the SAE Supermileage® competition with an entirely new team. As such the vehicle will be a completely new design. The vehicle will be a three-wheeled recumbent bicycle design with two wheels at the front for steering and one located in the center at the rear that is to be powered. This configuration was chosen because only powering one wheel means no differential is needed, which increases overall mechanical efficiency by simplifying the powertrain. The general layout of the vehicle also lends its self to an aerodynamically optimized “teardrop” shape.
Team Gasbusters’ Design Processes:
Team Gasbusters’ Fabrication Processes:
The frame was manufactured from square 1/8” wall 1 ¼” and 1/16” wall 1” 6061 T-6 Aluminum tubing; 1 ¼” square tubing was used in areas of high stress while 1” square tubing was used for the rest of the frame seen in the figure below. This material was primarily chosen due to its high strength to weight ratio. The roll hoop of the frame was engineered to ensure that it could withstand a 250lbf load in any direction as per SAE regulations. The floor will be an aluminum sheet tack-welded to the bottom of the frame and will provide non critical structural support. This will provide improved aerodynamics by cleaning up the path of the air underneath the vehicle, as well as separating the driver from the pavement.
The front wheels will be supported by lefty hubs, manufactured by Cannondale mountain bikes. These hubs are intended to be mounted on one side, and we do not expect to experience any problems with the wheels during operation. In addition to this, lefty hubs are designed to accept disk brake rotors, which will provide ample stopping power. The wheels will be wrapped with medium-weight Polyfiber fabric to reduce drag.
The engine will be mounted directly behind the driver so that the distance from the engine to the rear wheel will be as short as possible. Power will be transmitted to a bicycle rear wheel using standard #35 chain. Because the BRIGGS & STRATTON Junior 206 engine delivers power from the left hand side, and all bicycle hubs can only accept power on the right, a free-wheel chain ring will be installed on the left hand side of the hub rather than the right to allow for power transmission to the rear wheel.
For the shell, 3/8” aluminum rod will be bent to desired angles and TIG welded to the frame. The intuitively designed aerodynamic skeleton can be seen above in Figure 1. It has been decided that the wheels will not be encompassed in the aerodynamic shell as the team feels the drag associated with the wheels is small enough to be neglected. After the aluminum shell skeleton has been fixed to the frame, Poly-fiber medium-weight fabric will be laid over the shell members to create a surface for the air to flow over. In order to properly fix the fabric to the frame a special glue will be applied to the surfaces where the frame contacts the fabric to promote adhesion. After the fabric is glued to the members, a heat source is used to shrink the fabric to a tight fit around the skeleton. Two openings will be placed on either side of the shell in the front to allow for headset clearance, steering, and braking components. For visibility, a clear Lexan polycarbonate wind screen will be placed on the front half of the shell and will conform to all line-of-sight requirements.
Sean is a 4th year Mechanical Engineering student that is specializing in fluid dynamics. Outside of school, Sean’s passions include everything the outdoors have to offer such as skiing, mountain biking, climbing, and hiking as well as power lifting.
Jesse likes to spend his spare time working on vehicles and fabricating things such as drift trikes and rock crawlers. He likes to be outdoors biking, hiking, offfoading, and camping with his friends. Jesse plans on graduating in spring of 2015 with a minor in math.
Adam will be graduating this coming spring with a BSME and a minor in mathematics. Adam is tying the knot this December after nearly a three year engagement. When not working valet or at school Adam spends his time shooting and riding motorcycles.
Ryan is a Mechanical Engineering student set to graduate in Spring of 2015. He enjoys working on his cars, motorcycles and anything oriented with performance. He enjoys spending time in the outdoors with his mountain bike .
Likes long walks on the beach and riding his mountain bike. As a senior Mechanical Engineer, Aaron hopes to find a job applying his new engineering skills to improve society in any way he can.