Acoustics, Dynamics, and Controls Commons^™

Experimental Characterization Of Hydraulic System Sound, Ben Kolb

Dissertations, Master's Theses and Master's Reports

The purpose of this research was to establish test methods for characterizing the interaction between the hydraulic fluid and hydraulic hose at clipping points in mobile heavy equipment hydraulic systems. A simple hydraulic circuit test bench was developed and the laboratory axial piston pump was characterized using ISO 10767-1. A direct relationship between the fluidborne noise and structureborne noise present at each hose clip location was observed for a specific operating condition using operating deflection shapes and structureborne noise measurements. This result shows that optimal hose clip placement can be a viable solution to structureborne noise reduction. Additionally, a modal …

Development Of A Fused Deposition 3d Printed Buoy And Method For Quantifying Wave Tank Reflections, Samantha G. Swartzmiller

Dissertations, Master's Theses and Master's Reports

Testing model scale prototypes is integral to the development of wave energy converter (WEC) technology. Model scale WECs are tested in wave tanks where they are subjected to repeatable wave fields. Their presence in water creates radiated waves that eventually reflect off tank walls disrupting the intended wave field. Fabrication of model scale WECs is another developing aspect of tank testing. Often model WECs are built of foam. Additive manufacturing is a promising alternative although the most common method, fused deposition modeling (FDM) 3D printing, does not typically produce waterproof parts. The goals of this work were 1) develop a …

Expendable 3d Printed Rescue Drone, Matthew Chapman, Nathan Knutty, Matthew Chapman

Williams Honors College, Honors Research Projects

This project team designed a 3D printed, expendable drone capable of flying for 80 minutes with a 5 lb payload in order to deliver rescue supplies to individuals in distress.

Metal Thin Film Stiffness Extraction Technique For Surface Acoustic Wave Filters, Travis R. Weismeyer

Electronic Theses and Dissertations

Accurate knowledge of the surface acoustic wave (SAW) properties propagating at the surface of a piezoelectric substrate with thin films, electrodes or temperature compensated films, is critical in SAW filter design to meet the target frequency response, power durability and performance prior to device fabrication. While reliable material constants exist for substrates such as LiNbO3 used in SAW filters, the absolute elastic constants associated with operational thin films used for electrodes or temperature compensation do not exist. Although the bulk values of the constituent materials are known, the composite film/substrate properties are difficult to predict since they depend strongly on …

Ultraviolet Imager Application For A Cube Satellite, Jason Grillo, Troy Hajjar, Brady Hill

Mechanical Engineering

This document serves as the final design review (FDR) report for the 2018 Cal Poly CubeSat Ultraviolet Imager senior project, sponsored by UC Berkeley Space Sciences Laboratories (SSL). SSL wants to monitor the ionosphere above Earth to gain a better understanding of its properties and particle interactions. Far Ultraviolet (FUV) imaging is a good way to obtain high quality images of the ionosphere and the Earth's auroras, and advancement in optic technologies have made cube satellites (CubeSats) an ideal vessel for a FUV imager, as they are relatively low-cost, lightweight, and can be repeatedly deployed. These CubeSat FUV imagers could …

A Numerical Flutter Predictor For 3d Airfoils Using The Onera Dynamic Stall Model, Pieter Boersma

Masters Theses

To be able to harness more power from the wind, wind turbine blades are getting longer. As they get longer, they get more flexible. This creates issues that have until recently not been of concern. Long flexible wind turbine blades can lose their stability to flow induced instabilities such as coupled-mode flutter. This type of flutter occurs when increasing wind speed causes a coupling of a bending and a torsional mode, which create limit cycle oscillations that can lead to blade failure. To be able to make the design of larger blades possible, it is important to be able to …

Streamwise Flow-Induced Oscillations Of Bluff Bodies - The Influence Of Symmetry Breaking, Tyler Gurian

Masters Theses

The influence of symmetry breaking on the flow induced oscillations of bluff bodies in the steamwise direction is studied. First, a series of experiments is conducted on a one-degree-of-freedom circular cylinder allowed to exhibit pure translational motion in the streamwise direction over a range of reduced velocities, 1.4 < U* < 4.4, corresponding to a Reynolds number range of 970 < Re < 3370. Two distinct regions of displacements were observed in reduced velocity ranges of 1.6 < U* < 2.5 and 2.75 < U* < 3.85. Measured force coefficients in the drag and lift direction were examined, along with the wake visualization, through the range of reduced velocities, to infer the resulting wake modes. A new Alternating Symmetric (AS) mode was found. This transition from symmetric to AS shedding occurred near the end of the first region of response. Similar tests were run with a square prism in the parameter space of 2.4 < U* < 5.8 and 757 < Re < 1900 over angles of incidence of 0° ≤ α ≤ 45°. A distinct region of lock-in is observed for α = 0°, 2.5°, 5°, 7.5° over 3.2 < U* < 5.4 for α = 0°, and decreasing with increasing α. The wake structures were found to be roughly symmetric for α = 0°, but transitioned towards asymmetry …

Mobile Opera Backdrop, Juan Villalobos, Robbie Behlman, Kevin Valencia

Mechanical Engineering

Opera San Luis Obispo requires an acoustically projecting stage backdrop for their future plan of deploying a mobile opera house. The custom stage backdrop must be low-cost, easy to assemble and must project the performance sound to outdoor audiences. Other design requirements include being transportable in a step van, the ability to be assembled quickly by a crew of two, resistance to various outdoor conditions, the ability to mount accessories from the walls, and should meet a budget of $5,000. With the scope of the project understood, the three-quarter project is outlined. During the first quarter, the main deliverables included …

Dyno-Mite Redesign, Brandon Joseph Miller, Daniel Robert Hoffman, Richard Demedici Young

Mechanical Engineering

The Cal Poly Mechanical Control Systems Laboratory currently employs an outdated device, known as the Motomatic, to teach students about various motor characteristics and control methods. These include open-loop vs. closed-loop control, speed vs. position control, and DC motor response curves. The current device does not function properly and produces unreliable data due to overwhelming non-linear effects such as stiction and shaft misalignment. Our team was tasked with designing a replacement device that retains many of the same educational goals as the original lab procedure, while also adding new educational goals pertaining to the device system dynamics. The new apparatus, …

The Influence Of Macroscale Stress Concentrations On The Near-Resonant Thermomechanics Of Mock Energetic Materials, Lauren A. Cooper, Allison R. Range, Jeffrey F. Rhoads

The Summer Undergraduate Research Fellowship (SURF) Symposium

The characterization of particulate composite energetic materials, both with and without stress concentration, is currently of great interest to the defense community. This work seeks to further characterize the self-heating effect of composite energetic plates, particularly around regions of high stress, when subjected to harmonic excitation near resonance. Mock energetic plates with macroscale stress concentrations are prepared in various compositions based on the PBXN-109 formulation, and are tested near the first resonant frequency using an electrodynamic shaker. The resulting mechanical and thermal responses are recorded using a laser Doppler vibrometer and an infrared camera, respectively. Upon comparison between the regions …

An Effective Methodology For Suppressing Structure-Borne Sound Radiation, Lingguang Chen

Wayne State University Dissertations

ABSTRACT

AN EFFECTIVE METHODOLOGY FOR SUPPRESSING

STRUCTURE-BORNE SOUND RADIATION

by

LINGGUANG CHEN

December 2017

Advisor: Dr. Sean F. Wu

Major: Mechanical Engineering

Degree: Doctor of Philosophy

This dissertation is primarily concerned with the development of an effective methodology for reducing structure-borne sound radiation from an arbitrarily shaped vibrating structure. There are three major aspects that separate the present methodology from all the previous ones. Firstly, it is a non-contact and non-invasive approach, which is applicable to a class of vibrating structures encountered in engineering applications. Secondly, the input data consists of a combined normal surface velocity distribution on a portion …

Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, David Leon Yoder

Masters Theses

Wind tunnel test customers continue to push the limits by producing air vehicle designs that produce high aerodynamic loads at the desired test conditions. These loads are a combination of steady aerodynamic, unsteady aerodynamic, and inertial forces. A methodology to monitor the health of a wind tunnel strain-gage balance has been developed. The objective of this methodology is to define the stress limits of the balance and monitor these limits so the balance can be safely tested without failure of the balance. A balance failure could result in costly damage to the wind tunnel model, support system, and the wind …

Quantifying And Mapping Induced Strain In Canvas Paintings Using Laser Shearography, Philip Klausmeyer, Matthew Cushman, Ivo Dobrev, Morteza Khaleghi, Ellery Harrington, Xiaoran Chen, Cosme Furlong

Morteza Khaleghi

Experimental Building Demonstration Model With Viscous Fluid Dampers, Blake Thomas Reeve, Brianna Jean Kufa, Aden Malek Stepanians, Sophie Carmion Ratkovich

Architectural Engineering

The Architectural Engineering major places a heavy emphasis on structural dynamics and the role of wind and seismic loading in building analysis and design. Buildings of high importance that are critical to community function, such as hospitals, often utilize supplemental damping devices like supplemental viscous fluid dampers or base isolators to reduce the overall demands on the structural system. The design and analysis of these dampers are typically not taught at the undergraduate level, and is frequently performed by mechanical engineers, in lieu of structural engineers.

To better understand and research building behavior with supplemental damping devices, our multi-disciplinary team …

Magnetic Bearing For Bently Nevada Rk4 Rotor Kits, Sean Fowler, Garrett Olson

Mechanical Engineering

Active Magnetic Bearings (AMB) are contact free bearings that support loads by magnetic levitation. This is accomplished by generating magnetic forces with electric current through a series of electromagnets surrounding a suspended rotor mass. Along with a set of electromagnets, an AMB assembly also consists of power amplifiers for each electromagnet, a controller, and proximity sensors. The proximity sensors provide rotor position feedback to the control system, which modulates power to the amplifiers [4]. Magnetic bearings are used in several industrial applications today, including but not limited to compressors, turbines, pumps, motors, and generators. Advantages of their utility include very …

Using The Moment Of Inertia As A Means Of Better Controlling The Speed Of Wind Turbines, Garrett L. Muhlstadt

Honors Program Projects

In the following document, the possibility of using the moment of inertia as a means of speed control for a wind turbine is explored. This document gives an introduction to wind energy and current speed control methods. This information was obtained through databases found at Benner Library. Also, an experiment was used to collect data and determine the relationship between the moment of inertia and angular velocity of a turbine. A model turbine was fabricated and powered by a fan while a Logger Pro program was used to record the angular velocity of the turbine. The moment of inertia of …

The University Of Akron Human Powered Vehicle Team, Maria E. Rizzo, Andrew J. Derhammer, Christopher M. Trowbridge, Timothy M. Nutt, Joseph R. Boyd, Jeremy W. Marcum, Jonathan E. Adams, Donald G. Haiss, Julia Wood, Brian D. Goshia, Scott T. Fagan, Joshua D. Everhard, Rebecca L. Slivka

Williams Honors College, Honors Research Projects

The University of Akron Human Powered Vehicle Team’s 2016 vehicle, Klokan, was designed, manufactured and tested with safety, reliability, performance and ease of use in mind. The vehicle is a fully faired tadpole trike with a lightweight aluminum frame constructed from 6061-T6 tubing having a total weight of 8.9 lbs. To complement the lightweight frame, the fairing is constructed from polycarbonate, PETG and carbon fiber strips which combine into a lightweight, easy to manufacture weather barrier and aerodynamic structure. Klokan was designed to be a safe and efficient mode of everyday transportation which ensures that riders are sufficiently protected by …

Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, John B. Potts Iii

University of New Orleans Theses and Dissertations

An anguilliform swimming robot replicating an idealized motion is a complex marine vehicle necessitating both a theoretical and experimental analysis to completely understand its propulsion characteristics. The ideal anguilliform motion within is theorized to produce ``wakeless'' swimming (Vorus, 2011), a reactive swimming technique that produces thrust by accelerations of the added mass in the vicinity of the body. The net circulation for the unsteady motion is theorized to be eliminated.

The robot was designed to replicate the desired, theoretical motion by applying control theory methods. Independent joint control was used due to hardware limitations. The fluid velocity vectors in the …

Development Of A Two-Fluid Drag Law For Clustered Particles Using Direct Numerical Simulation And Validation Through Experiments, Ahmadreza Abbasi Baharanchi

FIU Electronic Theses and Dissertations

This dissertation focused on development and utilization of numerical and experimental approaches to improve the CFD modeling of fluidization flow of cohesive micron size particles. The specific objectives of this research were: (1) Developing a cluster prediction mechanism applicable to Two-Fluid Modeling (TFM) of gas-solid systems (2) Developing more accurate drag models for Two-Fluid Modeling (TFM) of gas-solid fluidization flow with the presence of cohesive interparticle forces (3) using the developed model to explore the improvement of accuracy of TFM in simulation of fluidization flow of cohesive powders (4) Understanding the causes and influential factor which led to improvements and …

Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The UMass Amherst Green Building Guidelines provide a framework for approaching new construction and major renovation projects at UMass Amherst that are undergoing LEED certification by focusing the conversation on green building aspects that are most important to the campus. They are intended to be the beginning of a dynamic conversation between designers, environmental consultants and constructors, university stakeholders, and users of new high performance buildings.

Influences Of Wind On Automotive Interior Sound Quality, Sara Huelsman, Patricia Davies, Daniel Carr

The Summer Undergraduate Research Fellowship (SURF) Symposium

The effects of noise on human health (both mental and physical) are well known, and motivation to decrease noise in daily life is prevalent. Wind noise within automotive interior cabins could be detrimental to human health and comfort because of the negative impact on speech intelligibility and fatigue overall. There is little information on human perception of wind noise in automobile interiors though Loudness and Articulation Index have been examined as predictors of human response. They have been found to predict well in some circumstances, but not in others. In this research, a variety of sound quality metrics are being …

The University Of Akron 2015 Sae Zips Baja Off-Road Racing Team 2015 Suspension System Design, Ryan W. Timura

Williams Honors College, Honors Research Projects

Baja SAE has been an important part of the University of Akron for the last 20 years. In the early stages, Zips Baja won many races and was one of the best Baja teams around. In more recent years, the teams have not been able to keep up the high place finishes. The 2015 Baja team aims to start a new trend of high place finishes for the years to come. With many design leaders returning from the previous year, passed down knowledge, and experience from last year, it should be an attainable goal.

Experiment And Simulation Of The Acoustic Signature Of Fatigued-Cracked Gears In A Two-Stage Gearbox, Matthew James Ostiguy

Master's Theses

This thesis focuses on the development of a health monitoring system for gearbox transmissions. This was accomplished by developing and understanding a two-stage gearbox computer model that emulates an actual gearbox test rig. The computer model contains actual gearbox geometry, flexible shafts, bearings, gear contact forces, input motor torque, output brake torque, and realistic gearbox imbalance. The gear contact force of each gear stage and the input bearing translational acceleration were the main outputs compared between a healthy gearbox and damaged gearbox computer model. The damage of focus was a fatigue crack on the input pinion gear. A sideband energy …

Team Nathan Suspension, Frankie J. Wiggins, Alex D. Seitz, Justin P. Bautista

Mechanical Engineering

Nathan Cooper is an 8-year old boy with Spinal Muscular Atrophy (SMA). SMA has affected Nathan’s muscle development and requires him to use the Standing Dani™ mobility device. The Standing Dani is a motorized standing wheelchair, or Wheelstand. Nathan controls and uses it to get around. Though the Standing Dani performs well for most functions, it has some distinct issues. The primary issue that this project addresses is its lack of suspension and the discomfort that Nathan feels as a result. After talking with our client, we developed several specifications generally related to geometry, safety, vehicle dynamics, and reliability. Many …

Autonomous Indoor Localization For Fire Safety And Resource Location Via Field Mapping Techniques, Jaeyoung Kim, Kartik Ariyur, Yan Cui, Benjamin D. Branch, Joshua Ebung Umo

Libraries Faculty and Staff Presentations

An overall result of this collaboration between the Mechanical Engineering Dept. and the Purdue University Libraries (PUL) should result in building a big data framework that make have knowledge transfer for similar large scale geospatial data implementations. Such may promote best practices of data management where the library skill sets may aid faculty research and student learning. Here, the PUL is concerned with advancing the Mechanical Engineering‘s STEM pipeline capacity with this type of research, collaboration and data management engagement.

Autonomous Indoor Localization For Fire Safety And Resource Location Via Field Mapping Techniques (Android Version), Joshua Ebung Umo, Yan Cui, Kartik Ariyur, Benjamin D. Branch, Jaeyoung Kim

Libraries Faculty and Staff Presentations

An overall result of this collaboration between the Mechanical Engineering Dept. and the Purdue University Libraries (PUL) should result in building a big data framework that make have knowledge transfer for similar large scale geospatial data implementations. Such may promote best practices of data management where the library skill sets may aid faculty research and student learning. Here, the PUL is concerned with advancing the Mechanical Engineering‘s STEM pipeline capacity with this type of research, collaboration and data management engagement.

Autonomous Indoor Localization Via Field Mapping Techniques, With Agricultural Big Data Application, Yan Cui, Kartik Ariyur, Benjamin D. Branch

Libraries Faculty and Staff Presentations

This joint collaboration between the library, the Mechanical Engineering department shows the current research of localizing an Android smartphone using big data collection and sensor fusion techniques. The original work is Autonomous Indoor Localization via Field Mapping Techniques which primarily designed as indoor fire and safety aid.

For Agricultural Big Data Use, the Android smartphone is being applied to in indoor greenhouse fire, safety and data knowledge design. Such may aid big data tool value to greenhouse fire and safety design and any data that may be important fieldwork considerations.

The indoor agricultural mapping application may be application to greenhouses …

Evaluating The Performance Of Fault Detection And Diagnostics Protocols Applied To Air-Cooled Unitary Air-Conditioning Equipment, David P. Yuill, James E. Braun

David Yuill

Fault detection and diagnostics (FDD) tools are increasingly being applied to air-cooled unitary air-conditioning systems. However, it is not known how well these tools work because there is no standard method of measuring or evaluating the performance of FDD. In the current paper the authors describe the common faults that FDD is applied to in unitary systems, and propose a method of evaluating the performance of FDD protocols. The method involves feeding measurement data through a candidate protocol and collecting and organizing the responses based upon the fault’s impacts on performance. A library of faulted and unfaulted measurement data has …

High Temperature Filter Test Unit Upgrades, Blair Frandeen, Will Schill, Erick Shewmaker, Joshua Turgeon

Mechanical Engineering

The purpose of this project was to improve the existing High Temperature Filter Test Unit (HTTU) by optimizing performance and adding new features. These features include viewing ports and a camera system for observation of tests, a leak detection system, and a flame impingement system. Additional considerations included improving the current operation of the HTTU by reducing test time and energy loss. The HTTU is designed to test High Efficiency Particulate Air (HEPA) filters at temperatures up to 1300 ˚F, creating conditions which simulate a fire in a chemical processing facility. The HTTU was originally built as a Cal Poly …

Rebounder Fatigue Test Machine, Caroline Reeves, Will Robertson, Ethan Flory

Mechanical Engineering

JumpSport, a company that designs and sells trampolines and trampoline accessories, has sponsored this senior project team to design, build, and test a trampoline fatigue test machine. The machine must simulate a person jumping on the trampoline to test the life of JumpSport’s fitness trampolines and kids’ trampolines. Partway through the design process, the objectives were altered and this senior project team was tasked with merging with another Cal Poly senior project group to create an all-inclusive test machine to accommodate both full-trampoline testing and individual bungee cord testing.

The final design is centered on a slider crank linkage driven …