Thesis (M.S., Mechanical Engineering) | In order to achieve improved efficiency and performance of the University of Idaho's Formula Hybrid SAE vehicle, a mathematical performance model was created through the thesis work of Samuel Wos. This thesis uses the vehicle performance model to specify hybrid architecture, determine energy allocation, and select batteries. Vehicle testing was conducted to verify the inputs and outputs of the model. Tests included roll-down, drag strip, and autocross as well as a frontal area calculation. From the roll-down test the rolling resistance coefficient was found to be 0.06 and the rotational inertia was found to be 2.25 lb-ft-sec2. From the drag strip test the travel time for the 250 feet track was 6.6 second for ICE-only, 6.4 seconds for electric-only, and 5.0 second for hybrid. During the autocross testing the hybrid system operated at an efficiency of 23.5 mpg. On the same autocross course the ICE alone operated at an efficiency of 18 mpg. Track times and fuel economy predicted by the performance model agreed with these findings. The frontal area calculation found the effective frontal area of the vehicle to be 8.2 ft2. The current model is highly accessible to undergraduate design teams participating in the FHSAE competition. A number of model refinements are suggested to make performance predictions even more accurate.
