Abstract This study was conducted to give insight to ways to produce simple and efficient ways to raise tractor trailer trucks mpg, thus lowering the cost annually of the average truck (which is currently about $100,000). This study’s main focus point was on the tractor because the tractor is responsible for two points of highest drag on the truck (front and gap). The current average tractor could be seen as an aerodynamic disaster while on the other hand this study explores the use of a right traingle shaped tractor, which is one of the most efficient shapes going into direct head winds. This study also exhibits the use of grooves on the tractor model to provide for smoother flow over the vehicle. The idea for grooves was derived from a pilot study exploring the usage of grooves for smoother flow and reduction in drag.

Need The average truck uses about 30,000 gallons annually One tractor trailer truck cost $100,000 annually with current diesel prices Trucks make up 80% of the US 580 billion dollar freight payroll Low mileage due to dirty aerodynamic structures Two highest points of drag located in tractor area

Knowledge Base Graph depicting the five highest areas of drag on a tractor trailer truck

Literature Review (Wood, Richard and Bauer, Steven) Studys also done by Toon (GTRI) Hammache (USC) McCallen (DOE)

Purpose The purpose of this experiment is to explore ways to make tractor trailer trucks more aerodynamically clean by modifying the tractor to the shape of a right triangle to reduce resistance to flow

Hypothesis Null Hypothesis- The treatment of grooves on a right triangle will come out to have the same drag as a normal right triangle. Based on a previous pilot study, the null hypothesis should be a true negative. Alternate Hypothesis- The treatment of grooves on a right triangle will reduce the drag on the right triangle by stabilizing flow over the right triangle. Based on a previous pilot study, the alternate hypothesis should be a true positive.

Pilot Study for Highest Drag Resistance CubeSphereConePyramid Test three trials in Pitsco Air Tech X Stream Wind tunnel at speeds of 100, 500, 900, 1300, 1700, 2100, 2500 and 2900 ft/min Testing for drag using Pasco force meter and plugging drag coefficient into drag equation (D=C d (ρ x v 2 /2)A Compare shape drag to each other, thus finding most efficient shape AirfoilCylinder Airfoil w/ Grooves Right Triangle Right Triangle w/ Grooves

The effects of grooved right triangles on drag Right triangle Right triangle with grooved front Right triangle with grooved sides Right triangle with grooved front and sides Test three trials in Pitsco Air Tech X Stream Wind tunnel at speeds of 100, 500, 900, 1300, 1700, 2100, 2500 and 2900 ft/min Testing for drag using Pasco force meter and plugging drag coefficient into drag equation (D=C d (ρ x v 2 /2)A Compare variable data to control and determine change in drag Compare best variable to average tractor’s drag and determine drag reduction