Mechanical Engineering Commons^™

Generation Of Premix Laminar Flame Speed Library, Sai Prashanth Kumar

Dissertations, Master's Theses and Master's Reports

The Laminar flame speed is an essential parameter in measuring turbulent premixed combustion applied in Spark ignition engines. Instead of using power-law correlations, which is valid only for particular ranges, the procedure for generating a premixed laminar flame speed library is defined using MTU – Master mechanism for a wide range of charge mixture conditions inside an engine combustion chamber: Temperature (300 – 700 K), Pressure (1 – 70 bar) and reactant mixture composition of equivalence ratio (0.4 – 2.0) Laminar flame speed library is generated for methane. The mechanism's performance was improved by adjusting the pre-exponential factor of the …

A Cfd Study Investigating Drag Reduction For Different Offset And Inline Distance For Two Trucks Platooning, Wael Mokhtar, Kyle Dinger, Shardul Kachare, Mdrazib Hossain, Colin Britcher

Mechanical & Aerospace Engineering Faculty Publications

The automotive industry invests huge resources to improve fuel consumption of commercial vehicles by improving their aerodynamic efficiency. Recently, numerous studies investigating the effect of platooning on aerodynamic drag of semi-trucks have been performed by researchers indicating a positive impact. For the present study, a three-dimensional computational study was performed to investigate the effect of varying offset and linear distance during platooning on the total drag of two semi-trucks. The study was conducted on a full-scale model using Reynold’s Averaged Navier-Strokes governing equations for a moving ground simulation using the STAR-CCM+ computational package. Furthermore, for turbulence, the standard k- …

Propagation Of Errors Through Coning, Sculling, And Scrolling Correction Algorithms, James D. Brouk, Kyle J. Demars

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper investigates the propagation of estimation errors through a common coning, sculling, and scrolling architecture used in modern day inertial navigation systems. Coning, sculling, and scrolling corrections often have an unaccounted-for effect on the error statistics of inertial measurements used to describe the state and uncertainty propagation for position, velocity, and attitude estimates. Through the development of an error analysis for a set of coning, sculling, and scrolling algorithms, mappings of the measurement and estimation errors through the correction term are adaptively generated. Using the developed mappings, an efficient and consistent propagation of the state and uncertainty, within the …

Efficiency Of Gas Turbine Engines, Tahir A. Upshaw

The Kennesaw Journal of Undergraduate Research

The following research involves conducting a confirmation of test bench results, and parametric cycle analysis. The results from these two methods of data collection is meant to show relationship between both. Where the data of the price induction can be verified with the parametric cycle analysis of the individual components to calculate the thrust and efficiency. Once we compare both methods, it will allow us to move on to part two of the research which involves determining how to make gas turbine engines more efficient based on the collected data.

Simulation And Modeling Of Cold-Wall Hypersonic Turbulent Boundary Layers On Flat Plate, Junji Huang, Gary L. Nicholson, Lian Duan, Meelan M. Choudhari, Rodney D.W. Bowersox

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) of flat-plate, zero-pressure-gradient turbulent boundary layers are presented for nominal freestream Mach numbers of 11 and 14 and a highly cooled wall (wall-to-recovery temperature of approximately 0.2). The flow conditions of the DNS are representative of the experimental data for a Mach 11.1 turbulent boundary layer on a flat plate that was tested at Calspan–University of Buffalo Research Center (CUBRC) and the operational conditions of the AEDC Hypervelocity Tunnel No. 9 at Mach 14. The wall shear stress and turbulent heat flux predicted by DNS show good comparisons with those measured at CUBRC and those modeled …

Erratum: Minimization Of The Kullback-Leibler Divergence For Nonlinear Estimation (Journal Of Guidance, Control, And Dynamics, (2017), 10.2514/1.G002282), Jacob E. Darling, Kyle J. Demars

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Erratum Notice In the original article [https://doi.org/10.2514/1.G002282], Eqs. (16b) and (18b) were typeset as (Formula Presented) which incorrectly show that the posterior covariance at time tk, denoted by Pk, is calculated about the prior mean, m−k. The correct forms of these equations are given by (Formula Presented) which show that Pk is calculated about the posterior mean, mk. All resulting analyses and simulations reported in the article were performed using the correct forms of the equations.

Information-Based Particle Flow For High Uncertainty Estimation, Kari C. Ward, Kyle J. Demars

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work presents a new formulation of the Gaussian particle flow filter derived using an information theoretic approach. The developed information flow addresses two problems with Gaussian particle flow: the lack of inherent meaning in the flow parameters and the inability to easily include modifications for a non-Bayesian update. Equivalency between Gaussian particle flow and information flow is established using a linear, Gaussian example. An orbit determination simulation with high initial uncertainty is used to demonstrate the consistent, robust performance of the information flow filter in situations where the extended Kalman filter fails.

Atv Dynamics And Pediatric Rider Safety, James T. Auxier Ii

Theses and Dissertations--Biomedical Engineering

It has been observed through numerous academic and governmental agency studies that pediatric all-terrain vehicle ridership carries significant risk of injury and death. While no doubt valuable to safety, the post-hoc approach employed in these studies does little to explain the why and how behind the risk factors. Furthermore, there has been no prolonged, widespread, organized, and concerted effort to reconstruct and catalog the details and causes of the large (20,000+) number of ATV-related injuries that occur each year as has been done for road-based motor vehicle accidents. This dissertation takes the opposite approach from a meta-analysis and instead examines …

Influence Of Size Effects On Surface Generation During Finish Machining And Surface Integrity In Ti-6al-4v, Ian S. Brown

Theses and Dissertations--Mechanical and Aerospace Engineering

Finish machining is an essential manufacturing process that is used to enhance the mechanical characteristics of critical components. The deformation that occurs at the tool and workpiece interface in finish machining significantly affects a host of component properties, commonly referred to as “surface integrity” properties. Surface roughness is a machining deformation-affected characteristic that is of high relevance in contemporary manufacturing. However, over recent decades it has been made clear that the material properties of the deformed surface layers are relevant to component performance as well. Predicting the overall surface quality of a machined component is of great relevance to the …

Development Of Universal Solver For High Enthalpy Flows Through Ablative Materials, Umran Duzel

Theses and Dissertations--Mechanical and Aerospace Engineering

Atmospheric entry occurs at very high speeds which produces high temperature around the vehicle. Entry vehicles are thus equipped with Thermal Protection Systems which are usually made of ablative materials. This dissertation presents a new solver that models the atmospheric entry environment and the thermal protection systems. In this approach, both the external flow and the porous heat shield are solved using the same computational domain. The new solver uses the Volume Averaged Navier-Stokes Equations adapted for hypersonic non-equilibrium flow, and is thus valid for both domains. The code is verified using analytical problems, set of benchmarks and also a …

Carbon Oxidation At The Atomic Level: A Computational Study On Oxidative Graphene Etching And Pitting Of Graphitic Carbon Surfaces, Simon Schmitt

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to understand the oxidation of solid carbon materials by oxygen-containing gases, carbon oxidation has to be studied on the atomic level where the surface reactions occur. Graphene and graphite are etched by oxygen to form characteristic pits that are scattered across the material surface, and pitting in turn leads to microstructural changes that determine the macroscopic oxidation behavior. While this is a well-documented phenomenon, it is heretofore poorly understood due to the notorious difficulty of experiments and a lack of comprehensive computational studies. The main objective of the present work is the development of a computational framework from …

Multiscale Modeling Of Carbon Fibers/Graphene Nanoplatelets/Epoxy Hybrid Composites For Aerospace Applications, Hashim Al Mahmud

Dissertations, Master's Theses and Master's Reports

Significant research effort has been dedicated for decades to improve the mechanical properties of aerospace polymer-based composite materials. Lightweight epoxy-based composite materials have increasingly replaced the comparatively heavy and expensive metal alloys used in aeronautical and aerospace structural components. In particular, carbon fibers (CF)/graphene nanoplatelets (GNP)/epoxy hybrid composites can be used for this purpose owing to their high specific stiffness and strength. Therefore, this work has been completed to design, predict, and optimize the effective mechanical properties of CF/GNP/epoxy composite materials at different length scales using a multiscale modeling approach. The work-flow of modeling involves a first step of using …

Large-Scale Inflatable Structures For Tunnel Protection: A Review Of The Resilient Tunnel Plug Project, Eduardo M. Sosa, Gregory J. Thompson, Gregory M. Holter, John M. Fortune

Faculty & Staff Scholarship

The protection of underground civil infrastructure continues to be a high priority for transportation and transit security agencies. In particular, rail transit tunnels running under bodies of water are susceptible to disruptions due to flooding caused by extraordinary climatic events such as hurricanes or other events resulting from human activities. Several events have taken place in the past decades that have demonstrated the need to mitigate vulnerabilities or, at least, minimize the consequences of catastrophic events. Although it is impossible to prevent all situations that can lead to flooding, damage can be substantially decreased by reducing the area affected by …

Fast Decision-Making Under Time And Resource Constraints, Kyle Gabriel Lassak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Practical decision makers are inherently limited by computational and memory resources as well as the time available in which to make decisions. To cope with these limitations, humans actively seek methods which limit their resource demands by exploiting structure within the environment and exploiting a coupling between their sensing and actuation to form heuristics for fast decision-making. To date, such behavior has not been replicated in artificial agents. This research explores how heuristics may be incorporated into the decision-making process to quickly make high-quality decisions through the analysis of a prominent case study: the outfielder problem. In the outfielder problem, …

Direct Numerical Simulations Of Acoustic Disturbances In Various Rectangular Nozzle Configurations, Nathaniel Hildebrand, Meelan M. Choudhari, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We perform Direct Numerical Simulations (DNS) to study the acoustic freestream disturbances radiating from the turbulent boundary layers along the contoured nozzle walls of a hypersonic wind tunnel with a rectangular test section. To begin with, the effects of the spanwise end walls are suppressed by confining the spanwise computational domain to a finite segment of the overall nozzle cross section and by imposing periodic boundary conditions across that spanwise domain. Besides providing a building-block configuration to reveal partial effects of the enclosed acoustic environment within the wind tunnel, these computations serve as a steppingstone toward the goal of fully-3D …

Direct Numerical Simulation Of Turbulent Pressure Fluctuations Over A Cone At Mach 8, Junji Huang, Lian Duan, Katya M. Casper, Ross M. Wagnild, Neal P. Bitter

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) were conducted to characterize the pressure fluctuations under the turbulent portion of the boundary layer over a sharp 7◦ half-angle cone at a nominal freestream Mach number of 8 and a unit Reynolds number of Reunit = 13.4 x 106/m. The axisymmetric cone geometry and the flow conditions of the DNS matched those measured in the Sandia Hypersonic Wind Tunnel at Mach 8 (Sandia HWT-8). The DNS-predicted wall pressure statistics, including the root-mean-square (r.m.s.) fluctuations and the power spectral density (PSD), were compared with those measured in the Sandia HWT-8. A good comparison between the DNS …

Thermodynamic Properties Of Hydroxylammonium Nitrate-Based Electric Solid Propellant Plasma, Matthew S. Glascock, Patrick D. Drew, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants controlled by electric current. An electric solid propellant may also be used in an electric propulsion system: specifically, an ablative pulsed plasma thruster. Previous experiments with the electric solid propellant known as high-performance electric propellant, or HIPEP, suggest its ablation processes are similar to the traditional propellant polytetrafluoroethylene (C2 F4). Better understanding of the ablation and the resulting propulsion performance of HIPEP requires a model of its vapor composition, bulk plasma quantities, and thermodynamic properties. Such a model was developed and favorably compared with previous analogous model predictions found in the …

Redesign And Analysis For Landing Gear Components, Daniel Clarke

Williams Honors College, Honors Research Projects

A project for Collins Aerospace, the company I co-op at, where I will redesign several components of a landing gear for a military program. Any structural/stress analysis will also be performed. The goal is to reduce weight while maintaining strength and structural integrity.

Rocket Motor Nozzle, Corey Hillegass

Williams Honors College, Honors Research Projects

For this honors research and senior design project, the authors will research, analyze, and manufacture a rocket motor nozzle for the Akronauts rocket design team. This research and design project will improve how the rocket design team will decide and manufacture nozzles going forward. The impact of this improvement allows the rocket design team to take steps toward being self-sustaining by manufacturing student designed parts as opposed to commercially bought parts. This will not only be successful in increasing student impact on future designs, but also provides a technical challenge for the authors and will present as an impressive feat …

Solar-Powered Exploration Of The Venus Atmosphere, Marc Migliozzi, Cory Everman, Rebecca Buerhle, Umar Muhammed, Steven Abbate, Chase Champagne

Williams Honors College, Honors Research Projects

The objective of this study was to design a solar powered, unmanned aircraft to orbit in the upper Venus atmosphere and search for signs of alien life. Topics of flight conditions, signs of life, basic mission plan, source of power, design process, instrumentation, and final designs are covered. Solar energy is ideal for this type of mission because it is the only reliable and abundant energy source accessible for long term space travel. The target altitude, being 60 to 70 km, has winds of up to 95 m/s. The aircraft will need to remain stable under such conditions. Due to …

Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based …

Thermal / Structural Analysis Of The Hb 650 Thermal Shield, Gerald J. Smith

Graduate Research Theses & Dissertations

Fermilab’s PIP-II project’s superconducting linear accelerator (Linac) will drive the next generation of particle accelerators through a revolution in beam intensity. Key to beam intensification are the high efficiencies of niobium-tin superconducting radiofrequency (SRF) cavities operating at cryogenic temperatures near 5 Kelvin. A multifaceted approach is employed to achieve and maintain the extreme temperature. Vacuum provides the first barrier to thermal convection. Physical thermal intercept zones further isolate the exterior shell vacuum vessel at 300 Kelvin from the supercooled beamline. The first thermal intercept lies just inside the exterior vacuum vessel forming the 40 Kelvin zone. This 40K thermal shield …

Magnetic Control Of Transport Of Particles And Droplets In Low Reynolds Number Shear Flows, Jie Zhang

Doctoral Dissertations

“Magnetic particles and droplets have been used in a wide range applications including biomedicine, biological analysis and chemical reaction. The manipulation of magnetic microparticles or microdroplets in microscale fluid environments is one of the most critical processes in the systems and platforms based on microfluidic technology. The conventional methods are based on magnetic forces to manipulate magnetic particles or droplets in a viscous fluid.

In contrast to conventional magnetic separation method, several recent experimental and theoretical studies have demonstrated a different way to manipulate magnetic non-spherical particles by using a uniform magnetic field in the microchannel. However, the fundamental mechanism …

Fabrication And Characterization Of Multifunctional Composites, Aditya R. Thakur

Doctoral Dissertations

“This study details the research to facilitate fabrication and characterization of novel structural composites reinforced with carbon fibers. Across industries, materials with high performance-to-weight ratio are sought after. Using carbon fibers as secondary phases in these proposed composites, specific characteristics can be tailored in these materials to manufacture strong, lightweight, high performance structures. The first part of the research focused on the improvement in the mechanical properties of the composites using carbon fiber reinforcement. As a part of this study, toughened ceramic composites with predictable failure patterns were produced using carbon fiber inclusions. A closed-form analytical model was developed to …

Finite Time Suboptimal Control Design Of Nonlinear Systems With Θ-D Technique And Implementation To Aerospace Applications, Jie Yao

Doctoral Dissertations

“A finite time suboptimal control strategy (named θ - D approximated algorithm) was proposed in this study, which can provide the control engineers with a novel effective and efficient design tool from the finite time optimal perspective. Based on the framework of this proposed method, the original nonlinear dynamics were formulated in pseudo-linear form, and the performance index was denoted by a linear quadratic regulator prototype in this research. After that, the approximated solutions to intractable Hamilton-Jacobi-Bellman (HJB) equation were acquired by putting vanishing perturbation terms into the performance index. By tuning the parameters in perturbation terms, semi-global stability and …

Wind Release Mechanical Sun Tracker, Tyler Andrus, Brady Fisher, Jt Gibson, Cynthia Rigby, Derek Smith

Mechanical and Aerospace Engineering

• Solar panel sun tracking system that releases solar panels to orient to wind flow in high wind conditions

• Operates on a single rotational motor

• Designed to be lightweight and portable

Afrl Downed Airman Recovery System, Daniel Cornia, James Bennett, Matthew Halton, Matthew Bennett, Brandon Haws, Tyson Compton, Jacob Needham, Daniel Spreier, Thory Van Dyke

Mechanical and Aerospace Engineering

For the 2020 Air Force Research Laboratory design competition, teams were challenged to develop a system to assist Combat Search and Rescue (CSAR) in recovering a downed pilot in contested waters.

In the event of a pilot ejecting from their aircraft, a GPS beacon notifies CSAR of the pilot’s approximate location. During the rescue operation, a swimmer from a CSAR crew enters the water and assists the isolated person (IP) to use rescue equipment.

The current procedure exposes an additional person to hazards and increases IP extraction time. The additional required personnel and setup time increases mission risk.

USU’s student …

Design, Build, Fly 2019-2020 Banner Towing Bush Plane, Brayden Barton, Carlton Collet, Talon Gamble, Daniel Gardner, Hayden Harmon, Daniel Scribner, Ryley Shingleton, Trevor Smith, Sabrina Snow

Mechanical and Aerospace Engineering

• Design: A bush plane capable of deploying and towing a banner in flight, carrying passengers, and taking off within 20 ft. Create simple systems capable of restraining the passengers and stowing, deploying, and releasing the banner.

• Build: The plane, passenger subsystem, and banner subsystem using durable and lightweight materials. Select a propulsion system with the necessary power and endurance to complete the missions.

• Fly: Three missions with the fastest lap times to achieve the highest score.

• Mission 1: Fly 3 laps within 5 minutes; take off in less than 20 ft.

• Mission …

Automated Cushion Ring Insertion System (Cris), Nathan Andersen, James Parberry, Chris Reid, Jeron Robbins, Kayden Atkin, Kody King, Mckay Mckinnon

Mechanical and Aerospace Engineering

Project Description

This purpose of this project is to prototype a proof of concept machine capable of installing a retaining ring into an airbag cushion.

Project Benefits

• Decreased installation time

• Better consistency and quality control

• Helps create a fully automated production line

Usu Baja Sae 2020, Adam Black, Trevor Nuamann, Cliff Rossberg, Ian Jeppsen, Tad Behunin, Josh Olsen, Kaulin Curtis

Mechanical and Aerospace Engineering

The 2020 USU Baja team addressed the following issues in the 2020 buggy design:

• Utilizing LotusSHARK software for suspension design: Completing a digital design of the buggy's suspension system in LotusSHARK allowed for optimization of suspension design.

• Redesign of brake system: Reducing the size of the brake pedal footprint was needed for increase space in the buggy for 4WD components.

• Implementation of 4WD: Significant bonus points could be earned in the SAE competition if the buggy has 4WD capabilities. The ability to switch between 2WD and 4WD was also desired to easily engage the best configuration for …