Date of Award

2016

Document Type

Open Access Master's Report

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Scott Miers

Committee Member 1

James DeClerck

Committee Member 2

David Wanless

Abstract

A competitive vehicle in Formula SAE needs to be easy for unskilled drivers to extract the maximum performance from. This requires a predictable and manageable torque curve. This report details the development of an intake manifold for a Formula SAE car from a vehicle-based approach to produce this manageable and predictable torque. The current vehicle was instrumented and driven on a representative track to determine the usage of available torque. Based on these findings an ideal torque curve was chosen that favored increased torque at upper engine speed ranges and decreased torque at lower engine speed ranges. A 1-D engine cycle simulation model was developed and calibrated from intake, cylinder, and exhaust pressures measured on a dynamometer. The combustion model used the Wiebe function to model the burn rate and determine the simulated cylinder pressure. A design of experiments was performed with the calibrated 1-D model to find the optimized intake manifold geometry. Primary runner length and inlet diameter as well plenum volume were investigated and sized to produce as close to the ideal torque curve as possible. Based on this geometry a 3-D CAD model was developed and 3-D printed for use on the engine. The fuel delivery and ignition timing of the engine with the 3-D printed intake manifold were tuned on a dynamometer and the torque curve produced was found to be similar to the predicted torque curve at the upper engine speed range but deviate at the mid-range. An on-track vehicle comparison of the new intake manifold to the old intake manifold was attempted but not completed due to cracking of the new intake manifold under vacuum on the vehicle.

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