Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
Date
6-2016
Primary Advisor
Christoph Maurer
Abstract/Summary
The original goal of this project was to complete the design and building of a disc brake energy conversion project started by a former senior project team, and then spend a majority of the year performing testing in order to see if the device could be used to accurately calculate the Joule's constant. However, due to unforeseen complications and obstacles, the design and manufacturing portion of the project ended up taking much longer than anticipated. A majority of this time was spent designing the hydraulic plumbing system that would actuate the brakes. The previous team purchased some hydraulic parts and left them unassembled with no hydraulic schematic, and in order to save money, one of our goals was to use as many of the previous team's purchased parts as possible. This led to us attempting to complete their hydraulic design using the few parts they had left behind. However, after some time we discovered that the parts they had purchased would not work with the system we were trying to create. After discussion with multiple professors and shop techs, we discovered a hydraulic schematic created by W.C. Branham that would be perfect for our device. After making a few changes to the design, we were able to start manufacturing the hydraulic system using hand-held tube benders and tube cutters. Once the tubing was assembled, we bled the air out of the hydraulic portion of the system and filled it with hydraulic fluid. Then, in order to measure the temperature of the thermistor in the copper brake pads, we programmed an Arduino read the thermistor and collect data. This left us with only three weeks to test; however, through our testing and analysis, we were able to calculate a Joule's constant within 35% of the accepted value. The error in the calculated value came from heat loss that was not accounted for by our thermal model for the system. In an attempt to reduce the heat loss, we insulated the rear of the thermistor using Styrofoam and improved the thermal conductivity between the thermistor and copper pad using thermal paste. Although this improved our measured temperature, we believe we were still losing a lot of heat out of the back of the copper pad. Even though we had limited time to test, we believe that we proved that with further testing and analysis this device can be used to accurately and consistently calculate the Joule's constant.
URL: https://digitalcommons.calpoly.edu/mesp/303