“The noblest pleasure is the joy of

understanding” – Leonardo da Vinci

Waste Heat Capture Senior Design Project ENGR 481

Cook Stove Thermo-Electric Generator Servant Engineering Project ENGR 381-382

Failure Analysis of a Double Torsion Spring Mechanical Engineering Design ENGM 400

Laminar Flow Nozzle Fluid Mechanics ENGM 330

Audio Amplifier Electrical Circuit Analysis ENGE 250

Simon Game FPGA Digital Logic Design ENGE 220

Maze Navigating Robot Engineering Principles 2 ENGR 152

Oscillating Air Engine Engineering Principles 1 ENGR 151

Overview The US Department of energy estimates that 20-50% of industrial energy input is lost to the environment as waste heat. Cascade Steel has asked my team to find ways to capture energy from a hot exhaust gas stream leaving their reheating furnace where billets of steel are heated and formed into rebar. The solution will offset green house gas emissions by lowering the mill’s energy consumption from the grid and save money long term.

Skills & Accomplishments Extracted • project manager • used EES as a computer modeling tool • practiced interpersonal skills through dialogues with multiple vendors • employed fundamental thermodynamics and heat transfer knowledge

Overview InStove builds institutional sized cooking stoves for developing populations that rely on biomass fuel. Their technology reduces smoke related illnesses and deforestation problems with a cleaner more efficient burn. Our project was to generate electricity with the waste heat from one of these stoves. The electrical power could be used to run water pumps and charge batteries or cell phones.

Skills & Accomplishments Extracted • project manager • data acquisition (Personal DaqView)

with thermocouples • made use of fundamentals of fluid

mechanics in design of a cooling circuit • enlisted knowledge of mechanical

designs as it applies to bolt strength and stiffness in mounting TEG modules

Overview For this project I chose to analyze a double torsion spring (used in the agriculture industry) that had failed. The results were that the part would have infinite life for bumps in the field less than half an inch high. The largest redesign considerations were to get rid of the stress concentration where the part failed but to remember that the failure of this part protects more expensive parts of the machinery from harm.

A close up of the fracture surface, showing crack growth, suggests fatigue failure

Finite element analysis in SolidWorks shows a stress concentration which agrees with where the part actually failed

Picture of the spring being used in the agricultural industry

Skills & Accomplishments Extracted • SolidWorks modeling and FEA tools • test development for spring properties • tensile and hardness tests

Approach: Spring Deflection My approach to this problem was to determine the force applied to the end of the spring as it ran in to different sized bumps and rocks. This allowed me to find the moment and thus stress that the part experienced for a given bump height. Fatigue from repeated use eventually killed this part as was made obvious by the fracture surface.

A custom test set up using a spring scale to determine the spring constant for the part

Simple relation of rock height and angle of deflection

A tensile test was conducted to determine the modulus of elasticity and ultimate strength

Overview For this project, the team and I decided to build a laminar flow device and try to measure the head loss of the water stream moving through the air. We built what we came to call the ‘flow cannon’ with straws, sponges, ASB pipe fittings and a nozzle that we machined ourselves. The straws and the sponges help to create laminar flow conditions. A bonus portion of the project was to install an led inside to see if light would be carried in the stream.

Skills & Accomplishments Extracted • applied knowledge of fluid

mechanics to measure head loss through the nozzle

• design and machining of aluminum and brass nozzle inserts

• worked as part of a team: teaching and helping give direction to the project

Overview The purpose of this project was to design a cross over network for an audio amplifier. There was a left and right channel for two small tweeters and a separate lower frequency channel for a larger speaker. I had to perform some calculations with the knowledge I had gained in the class to find resistor and capacitor values that would filter the frequencies I wanted to each channel. Building an enclosure was another part of the project which I enjoyed very much.

Skills & Accomplishments Extracted • first exposure to soldering • implementation of

knowledge concerning circuit design

• design and build of custom enclosure

Overview This was a final semester project for Digital Logic in which we were to program a Simon game. The game board would play a pattern for you to repeat and then increment with every success. We used Verilog to program a Nexys2 FPGA board to control a interfacing board that contained: four buttons with RGB leds, a small speaker to play success and failure tones, and an lcd screen. A PRNG (pseudo-random number generator) was used to create a new pattern for each game.

Skills & Accomplishments Extracted • use of Verilog to

program the Simon game

• completed project under tight time constraints

• applied knowledge of digital logic

Overview In this project I wrote code in Arduino C to guide a robot through an unknown maze. The robot had several infrared sensors for sensing the walls of the maze. An added feature was that the robot had to know when it got to the end of the maze, rotate 360 degrees and then turn around and come back out of the maze. To accomplish this I created a compass that would update with each 90 degree turn the robot made.

Skills & Accomplishments Extracted • Programming in Arduino C • Use of state machines, timers,

counters and flags in a sketch

Overview The purpose of this project was to design and build an air powered engine. I used solid works to model the engine and make drawings for the building phase. There were several categories to design for and compete in. My engine won the minimum vibration category during the class competition and cost a total of $22 in materials.

Skills & Accomplishments Extracted • SolidWorks modeling,

drawings, and motion study

• award for minimum vibration

• learned to machine with a mill, lathe, band saw, and drill press