Mechanical Engineering Commons^™

Measurement And Prediction Of The Onset Of Intermittent Dryout During Blowdown Transients For Upward Annular Flow, Bradley A. Statham

Open Access Dissertations and Theses

The effect of pressure transients on the onset of intermittent dryout in upward annular flow was experimentally investigated in order to resolve the conflict between the observations drawn from two major data sets in the literature. A delay in time to the onset of dryout at the test section exit relative to the time predicted based on steady-state data was observed in the R-12 experiments of Celata et al (1988; 1991). Steady-state prediction methods were sufficient to predict the upstream progression of a pre-existing dryout front in the water experiments of Lyons and Swinnerton (1983). Steady state and pressure transient ...

Shape Optimization Of Airfoils Without And With Ground Effect Using A Multi-Objective Genetic Algorithm, Yilei He

Engineering and Applied Science Theses & Dissertations

The focus of this thesis is on shape optimization using a genetic algorithm. A multi-objective genetic algorithm (MOGA) is employed to optimize the shape of an airfoil to improve its lift and drag characteristics, in particular to achieve two objectives simultaneously that is to increase its lift as well as its lift to drag ratio. The commercially available software FLUENT is employed to calculate the flow field on an adaptive structured mesh, which is generated by the commercial mesh generating software ICEM. The flow field is calculated using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a two equation k-ω ...

A Cfd Assisted Control System Design For Supercritical Water Cooled Reactor, Rohit V. Maitri

University of Western Ontario - Electronic Thesis and Dissertation Repository

In this study, the methodology to construct a control system based on computational fluid dynamics (CFD) simulations is developed for supercritical water cooled reactor (SCWR). The CFD model using Reynolds Stress Model (RSM) and k-w SST model is validated with the experimental cases of steady state and vertically up flowing supercritical water in circular tubes for normal heat transfer and deteriorated heat transfer (DHT) cases. This model is extended to simulate the transient thermal-hydraulic behaviour of supercritical fluid flow and heat transfer, and the results are also compared with the 1-D numerical model, THRUST. The DHT phenomenon is investigated using ...

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Mechanical & Materials Engineering Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further ...

Vehicle Multi-Pass Rut Volume And Mobility Power Study, William W. Barbour

Pursuit - The Journal of Undergraduate Research at the University of Tennessee

This paper presents the relationship between applied power by a wheeled vehicle to soil and the rutting effects. Specifically, a strong positive relationship was found between cumulative applied power and total rut volume across multiple passes by the vehicle over the same tracks. Field-testing was conducted using a high-mobility multi-purpose wheeled vehicle (HMMWV) and two distinct soil types. Sensors on the vehicle measured torque and angular velocity of each of the four wheels, from which applied power was calculated. A rut profile meter was used to document the shape of the rut after set numbers of passes and this profile ...

Measurement Of The Absorption Coefficient Of Sound Absorbing Materials Under A Synthesized Diffuse Acoustic field, Olivier Robin, Alain Berry, Olivier Doutres Ph.D., Noureddine Atalla

Olivier Doutres Ph.D.

This letter proposes an experimental method to estimate the absorption coefficient of sound absorbing materials under a synthesized diffuse acoustic field in free-field conditions. Comparisons are made between experiments conducted with this approach, the standard reverberant room method, and numerical simulations using the transfer matrix method. With a simple experimental setup and smaller samples than those required by standards, the results obtained with the proposed approach do not exhibit non-physical trends of the reverberant room method and provide absorption coefficients in good agreement with those obtained by simulations for a laterally infinite material.

Logic And Methodology For Hierarchical Monitoring As A Means Of Fault Detection In Existing Large Scale, Data Rich Hvac Systems, Wendy Kisch

Mechanical Engineering White Papers

The purpose of this research is to develop effective methods of noncapital improvements in the operation of existing large scale data-rich heating, ventilation, and air conditioning (HVAC) systems, through the use of system data commonly routinely logged by building automation systems. Using the Iowa State University campus system as a test bed, we develop a systematic hierarchical method of HVAC system analysis and the setting of monitoring schemes. Our approach takes account of commonalities of location, use, subsystem identity, equipment type, etc. provided by basic engineering knowledge in order to monitor for signals of abnormal/degraded system behavior. It takes ...

A Study On The Vibrational Performance Characteristics Of An E22 Isolator After Outgassing And Bake-Out, Alma Melendez

Master's Theses and Project Reports

The launch environment experiences many vibration, shock, and acoustic loads. A great concern is the high random vibration levels that can damage components and spacecraft structures, which can cause a mission failure. An effective method of reducing high frequency energy is using isolators. Overall, the need for vibration isolation has been increasing because there has been an increase in the use of mechanisms in which vibrations are prevalent. In addition, there has not been extensive research on the effects of isolators that are outgassed and cured. Therefore, it is important to investigate and understand the vibrational effects on isolators. It ...

An Experimental Study Of Heat Transfer Coefficients And Friction Factors In Airfoil Leading Edge Cooling Cavities Roughened With Slanted Ribs, Benjamin S. Tom

Mechanical Engineering Master's Theses

In turbine blade design, the use of turbulators in airfoil cavities has been a preferred means to cool the metal temperatures within the airfoil. Temperatures in the turbine section of a jet engine can easily reach beyond material temperature capability limits and without any internal cooling, the turbine blades will begin to creep and eventually lead to engine failure. The introduction of turbulators has provided a means to increase the heat transfer coefficient within the airfoil cavities and help promote turbulence and better mixing to facilitate convective cooling. In this study, 4 different test rigs were experimented upon with each ...

Blds Articulated Mounting Feet, Mitchell D. Conn, Chris Mazzucco

Mechanical Engineering

This final report summarizes all of the efforts of the Senior Project aimed at creating Articulating Mounting Feet for the BLDS. The project focuses on improving the design of the mounting feet for the current Boundary Layer Data System at Cal Poly, San Luis Obispo. Dr. Russ Westphal, the project’s sponsor, wishes that our team focus primarily on a reliable and lightweight mount design for a curved wing, with only transverse curvature. Dr. Westphal is currently researching the boundary layer effects on airplane wings at Cal Poly, and the ability to mount to a multitude of surface contours would ...

Feel Of The Ocean: Final Report, Ian E. Hoffman, Kevin T. Dunlea, Ryan A. Palo

Mechanical Engineering

The overall goal of this project is to create a system that will enhance the audience’s sense that they are actually in the ocean, surrounded by whales, as they attend the Music Department’s 2014 Spring RSVP show. We have designed something that, through the interaction of light and moving fabric, will augment the performance.

Peek Wear Test System, Michael Brown, Mason Chellemi, Allian Roman

Mechanical Engineering

The wear characteristics of PEEK carbon fiber composites are not well understood in comparison to high strength materials in common use such as steel, aluminum, and carbon fiber epoxy. This lack of understanding limits the applications in which the superior strength to weight ratio and stiffness of PEEK carbon fiber composites may be utilized with confidence to situations in which there are no significant bearing surface interactions between nearby components. The objective of this project was to design, build, and test a machine that is capable of evaluating the behavior of PEEK carbon fiber composites in a long term, high ...

Science Of Water Table, Tim Haigh, Kris Francis, Nick Schlemmer

Mechanical Engineering

No abstract provided.

Formula Sae Cooling System Design, Lisa Van Den Berg, Brandon Lofaro

Mechanical Engineering

The overall objective of this senior project is to develop, via testing and analysis, a guided process that will aid the Cal Poly Formula SAE team in designing their cooling system. More specifically, a set of designed tests will yield the results necessary in determining a combination of fan and radiator that will achieve appropriate cooling.

A test section that has the capability of interfacing with both the wind tunnel in the Thermal Science Lab and a radiator will be used to facilitate the necessary experiments. The wind tunnel is powered by fan controlled by a variable frequency drive that ...

Rotating Test Apparatus, Brian David Yale, David George Shelton

Mechanical Engineering

No abstract provided.

Adapted Pool Cue, Cole Clark, Daniel Patterson, Michelle Cheung, Dylan Sauer

Mechanical Engineering

Our primary goal was to develop an adaptive device to allow a user with limited upper body mobility to more effectively play a game of pool. Within this goal it was important to design around the concept of a least restrictive environment, in order to provide the user with as close to a standard pool playing experience as possible. The device was designed to specifically meet the needs of John Lee, an Assistive Technology Specialist at Cal Poly's Disability Resource Center. Mr. Lee has muscular dystrophy, which limits his upper and lower body mobility and currently requires his use ...

Low-Cost Strider For Guatemala, Nicole Catherine Cooper, Gonzalo Hernandez, Jared W. Tower

Mechanical Engineering

The purpose of this project was to create a strider, a type of standing rehabilitation device, for children in developing countries who have trouble walking and supporting their full body weight. The project was initially brought to us by Cal Poly professor Brian Self, who had visited a clinic in San Marcos and determined that there were children there who had difficulties with walking and were a need for a rehabilitation device. The team discussed the problem with Dr. Self, Matt Robinson (a local San Luis Obispo prosthetist), and Cal Poly physics professor Pete Schwartz, all of whom had visited ...

Lightweight Uav Launcher, Ben Miller, Christian Valoria, Corinne Warnock, Jake Coutlee

Mechanical Engineering

This report discusses the design, construction, and testing of a lightweight, portable UAV launcher. There is a current need for a small team of soldiers to launch a US Marine Tier II UAV in a remote location without transport. Research was conducted into existing UAV launcher designs and the pros and cons of each were recorded. This research served as a basis for concept generation during the initial design development stage. It was required that the design weigh less than 110 lbs, occupy a smaller volume than 48" x 24" 18" in its collapsed state, be portable by a single ...

Adaptive Kayak Seating: The Tide Rider 360, Irvin Camacho, Grant Petersen, Audrey Riddle, Andrea Voigt

Mechanical Engineering

The Adaptive Paddling Program at California Polytechnic State University has sponsored the construction of an adaptive kayak seat, the Tide Rider 360, to provide paddlers with disabilities sufficient trunk support while out on the water. In particular, this design focused on providing the least restrictive environment for all users while still providing sufficient lateral, neck, back, and hip support. This seat is intended for use in the quarterly Adaptive Paddling Program to allow people with disabilities to experience the joys of kayaking in the most comfortable and supportive environment possible.

The following report details the background research, design development, manufacturing ...

Team Joseph: Adaptive Aquatic Device, Paul Sands, Lilly Hoff, Andrea Voigt

Mechanical Engineering

The scope of this project included designing and fabricating an adaptive aquatic device for Joseph, a 20 year old student in the Special Education Program at San Luis Obispo High School with a subset of cerebral palsy known as spastic quadriplegia. The project was presented at the beginning of the Fall 2013 quarter to the mechanical engineering students at Cal Poly with the aspiration that a team of engineers would construct a device that would allow Joseph, his friends and family to compete in their first triathlon on July 27, 2014. The project was humbly accepted by mechanical engineering students ...