Mechanical Engineering Commons^™

Evaluation Of Flux Correction On Three-Dimensional Strand Grids With An Overset Cartesian Grid, Dalon G. Work

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Simulations of fluid flows over complex geometries are typically solved using a solution technique known as the overset meshing method. The geometry is meshed using grid types appropriate to the local geometry in a patchwork fashion, rather than meshing the entire geometry with one type of mesh. The strand-Cartesian approach is a simplification of this process. While high-order accurate solvers on Cartesian grids are simple to implement, strand grids are usually restricted to second-order accuracy, resulting in poor quality solutions. Flux correction is a high-order accurate solution method, specifically designed for use on strand grids. The flux correction method on …

Characterization Of The Thermal Resistance Of Grain Boundaries Of Cerium Oxide, Jesse Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many materials are made up of small crystals, or grains. Grain boundaries are the interfaces between two grains and affect the flow of heat through the material. These interfaces serve to interfere with the energy carriers by scattering or disrupting them. Because of the negative effect these interfaces have on these energy carriers, they inhibit heat flow and act as thermal resistors. The thermal boundary resistance between two grains of the same material is sometimes referred to as the Kapitza resistance, although this term is also used to describe the thermal resistance between solid/solid interfaces of different materials or solid/liquid …

Water Entry Impact Dynamics Of Diving Birds, Saberul Islam Sharker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plunge diving and surface diving are two main techniques used by seabirds for foraging purposes. While some plunge divers can dive into the water at very high speeds (24 m/s), surface divers do not. This study analyzes the free-surface impact of 3D printed bird head models with embedded accelerometers to determine why surface divers cannot dive safely at high speeds. The problem is investigated in the context of impact jerk where surface divers, unlike plunge divers, are found to experience non-dimensional jerk (J^∗) values exceeding a safe limit. This approach portrays itself as an unconventional yet effective method …

Mechanical Performance Of Natural / Natural Fiber Reinforced Hybrid Composite Materials Using Finite Element Method Based Micromechanics And Experiments, Muhammad Ziaur Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A micromechanical analysis of the representative volume element (RVE) of a unidirectional flax/jute fiber reinforced epoxy composite is performed using finite element analysis (FEA). To do so, first effective mechanical properties of flax fiber and jute fiber are evaluated numerically and then used in evaluating the effective properties of flax/jute/epoxy hybrid composite. Mechanics of Structure Genome (MSG), a new homogenization tool developed in Purdue University, is used to calculate the homogenized effective properties. Numerical results are compared with analytical solution based on rule of mixture, Halpin-Tsai as well as Tsai-Hahn equations. The effect of the volume fraction of the two …

Satellite Sequencing Optimization Using A Genetic Algorithm, Andrew Verstraete

Research and Creative Activities Poster Day

The problem of mission design for a robotic servicing satellite in geosynchronous Earth orbit (GEO) was investigated. A representative set of potential client satellites was selected, and operational needs were randomly assigned based on the average number of GEO retirements, anomalies, and repositioning maneuvers that currently occur each year. An objective function was developed to represent the value of servicing mission sequences, including client fees, time penalties, and operational risk. A genetic algorithm was then used to find sequences of operations on the potential client set that maximized the objective function’s value. Scenarios were analyzed with the database of satellites …

Method And Shear-Driven Micro-Fluidic Pump, Nihad E. Daidzic

Aviation Department Publications

United States Patent Application, Publication Number US 2017/0096990 A1, Publication Date April 6, 2017.

An example includes an apparatus to pump a fluid. The apparatus includes a housing extending along a length defining an elongate interior, an actuator in the housing, conforming to the elongate interior, the actuator including a plurality of lumens, each having a length extending substantially parallel to the elongate interior, each from around 10 to 200 micrometers across and an actuator configured to oscillate the actuator in the actuator housing along the length of the elongate interior with a rate differential between movement in a first …

Tracking Characteristics Of Tracer Particles For Piv Measurements In Supersonic Flows, Fang Chen, Hong Liu, Zifeng Yang, Hui Hu

Mechanical and Materials Engineering Faculty Publications

The tracking characteristics of tracer particles for particle image velocimetry (PIV) measurements in supersonic flows were investigated. The experimental tests were conducted at Mach number 4 in Multi-Mach Wind Tunnel (MMWT) of Shanghai Jiao Tong University. The motion of tracer particles carried by the supersonic flow across shockwaves was theoretically modelled, and then their aerodynamic characteristics with compressibility and rarefaction effects were evaluated. According to the proposed selection criterion of tracer particles, the PIV measured results clearly identified that the shockwave amplitude is in good agreement with theory and Schlieren visualizations. For the tracer particles in nanoscales, their effective aerodynamic …

Biomass Cookstoves: An Empirical Study Into The Relationship Between Thermal Efficiency And Tending Practices For The Developing World, Erin Peiffer

Honors Theses

More than 2 billion people in the world use biomass stoves for cooking and heating their homes. Due to incomplete combustion, toxic byproducts such as soot, nitrous oxides and carbon monoxide gasses form. These toxic substances contribute to pollution and can lead to serious health issues over time if inhaled leading to approximately 4 million premature deaths each year. The formation of these toxic substances can be mitigated, in part, through the introduction of increased turbulence intensity allowing for the so-called “well-stirred combustion regime”. Here we will be exploring the health, environmental, and social effects of biomass combustion in the …

Design Of An Opposed-Piston, Opposed-Stroke Diesel Engine For Use In Utility Aircraft, Luke Kozal

Honors Theses

The objective of this thesis was to determine the feasibility of using an opposed-piston, opposed-stroke, diesel engine in utility aircraft. Utility aircraft are aircraft that have a maximal takeoff weight of 12,500lbs. These aircraft are often used for transportation of cargo and other goods. In order to handle that weight, many of the aircraft are powered by turboprop engines. Turboprop engines are a style of jet engine with power capabilities ranging from 500 to several thousand horsepower (hp). They are expensive engines, and in the case of the Piper Mirage, substituting the piston engine with a turboprop engine can increase …

Development Of An Analysis And Design Optimization Framework For Marine Propellers, Ashish C. Tamhane

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, a framework for the analysis and design optimization of ship propellers is developed. This framework can be utilized as an efficient synthesis tool in order to determine the main geometric characteristics of the propeller but also to provide the designer with the capability to optimize the shape of the blade sections based on their specific criteria.

A hybrid lifting-line method with lifting-surface corrections to account for the three-dimensional flow effects has been developed. The prediction of the correction factors is achieved using Artificial Neural Networks and Support Vector Regression. This approach results in increased approximation accuracy compared …

Modeling And Computation Of The Maximum Braking Energy Speed For Transport Category Airplanes, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

Transport-category or FAR/CS 25 certified airplanes may occasionally become braking energy capacity limited. Such limitation may exist when heavy airplanes are departing airports at high-density altitudes, on relatively long runways, and/or possibly with some tailwind component. A maximum braking energy VMBE speed exists which may limit the maximum allowable takeoff decision/action speed V1. The ever-existing possibility of high-speed rejected takeoff in such conditions may also limit the airplane gross weight for declared available distances. To gain deeper insights and acquire better understanding of the topic, a theoretical model of the maximum braking energy and the related VMBE speed for T-category …

P26. Global Exponential Stabilization On So(3), Soulaimane Berkane

Western Research Forum

Global Exponential Stabilization on SO(3)

Phonon Interference In Crystalline And Amorphous Confined Nanoscopic Films, Zhi Liang, Thomas E. Wilson, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Molecular Dynamics Phonon Wave Packet Simulations, We Study Phonon Transmission Across Hexagonal (H)-BN and Amorphous Silica (A-SiO₂) Nanoscopic Thin Films Sandwiched by Two Crystalline Leads. Due to the Phonon Interference Effect, the Frequency-Dependent Phonon Transmission Coefficient in the Case of the Crystalline Film (Si|h-BN|Al Heterostructure) Exhibits a Strongly Oscillatory Behavior. in the Case of the Amorphous Film (Si|a-SiO₂|Al and Si|a-SiO₂|Si Heterostructures), in Spite of Structural Disorder, the Phonon Transmission Coefficient Also Exhibits Oscillatory Behavior at Low Frequencies (Up to ∼1.2 THz), with a Period of Oscillation Consistent with the Prediction from the Two-Beam …

In-House Fabrication Of Temperature Sensitive Paint For Turbine Cooling Research, Mayur D. Patel, Mark A. Ricklick

Beyond: Undergraduate Research Journal

The Temperature Sensitive Paint (TSP) is a widely used method in measuring and visualizing flow separation and heat transfer. Compared to the cost and time consumption needed for methods such as pitot tubes, temperature sensitive paint is a cheaper alternative. Due to high usage in College of Engineering research projects, it was determined that in house fabrication of temperature sensitive paint would reduce time and cost limitations. For initial stages, literature research was performed to determine the recipe of intensity based TSP with luminophore and polymer binder that operated optimum at temperatures from 0-100°C. Europium III thenoyltrifluoroacetonate was determined to …

The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney

Master's Theses

While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …

Multi-Stage Nozzle-Shape Optimization For Pulsed Hydrogen-Air Detonation Combustor, Francesco Ornano, James Braun, Bayindir H. Saracoglu, Guillermo Paniagua

School of Aeronautics and Astronautics Faculty Publications

hermal engines based on pressure gain combustion offer new opportunities to generate thrust with enhanced efficiency and relatively simple machinery. The sudden expansion of detonation products from a single-opening tube yields thrust, although this is suboptimal. In this article, we present the complete design optimization strategy for nozzles exposed to detonation pulses, combining unsteady Reynolds-averaged Navier-Stokes solvers with the accurate modeling of the combustion process. The parameterized shape of the nozzle is optimized using a differential evolution algorithm to maxi­ mize the force at the nozzle exhaust. The design of experiments begins with a first optimization considering steady-flow conditions, subsequently …

A Multiscale Model For Damage Progression And Detection In Piezo/Pyroelectric Composite Laminates, Yehia Bahei-El-Din, Amany Micheal

Centre for Advanced Materials

Assessment of damage initiation and progression in composite structures reinforced with electrically active filaments is modelled in a multiscale analysis. The analysis developed is a two-tier, interactive analysis, which involves two length scales; macroscopic, and microscopic. The proposed multiscale analysis provides seamless integration of the mechanics at the two length scales, including piezoelectric and pyroelectric coupling effects and damage under overall thermomechanical loads and an electric field applied to electroactive fibers. The macromechanical analysis is performed for multidirectional, fibrous laminates using the lamination theory, including bending, and the micromechanical analysis is performed using a two-phase model and a periodic array …

Detecting Laminate Damage Using Embedded Electrically Active Plies – An Analytical Approach, Amany Micheal, Yehia Bahei-El-Din

Centre for Advanced Materials

Assessment of damage initiation and progression in composite laminates with embedded electrically active plies is modeled. Utilizing electrically active layers embedded in composite laminates as damage sensors is proposed by several researchers and is mainly assessed experimentally. Sensing damage using embedded electrically active plies is generally preferred over the use of surface mounted PZT wafers since the range of the latter is limited to a very narrow area underneath the surface, while multiple damage mechanisms can generally be found in several plies of the laminate. The solution presented invokes two levels of analysis. Firstly, on the laminate level, applied membrane …

Weather Balloon Payload Box, Shellbie Liberty

All Undergraduate Projects

A payload box holding a self-rotating camera was constructed to go on a weather balloon that will document the upcoming solar eclipse on August 21, 2017. A group of physics students, and the paper’s author, are working under Dr. Darci Snowden on the CWU Near Space Observation Team for research dedicated to the eclipse in Oregon. Various projects, including the payload box, are being designed to go up on a high altitude weather balloon. The payload box was designed and constructed to withstand the impact force of falling from 120,000 ft. This was done so the box could be reusable …

Mechanical And Aerospace Engineering, 2016-2017, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

• Letter from the Department Chair
• Mechanical and Aerospace Engineering Wins Grant from DENSO North America Foundation
• NSF $452,399 award to bring state-of-the-art instrument to WMU
• Faculty Research
• Faculty Summer Research
• Research in Fluid Mechanics and Aerodynamics
• Auto lab upgrades make it a premier teaching and research facility
• MAE faculty

Resilient Control Of Active-Passive Networked Multiagent Systems In The Presence Of Persistent Disturbances, Dzung Tran, Tansel Yucelen, John Daniel Peterson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An active-passive networked multiagent system consists of agents subject to inputs (active agents) and agents without any inputs (passive agents). Specifically, this class of networked multiagent systems utilizes a novel form of dynamic consensus filters, where the states of all agents converge to the average of the exogenous inputs applied only to the active agents, and it has broad practical applications including, for example, real-time situational awareness and data gathering using sensor networks and distributed control of multirobot systems. In this paper, we focus on active-passive networked multiagent systems that are subject to constant and/or harmonic exogenous disturbances. In particular, …

Molecular Simulation Of Steady-State Evaporation And Condensation: Validity Of The Schrage Relationships, Zhi Liang, Thierry Biben, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Accuracy, or Even the Validity, of the Schrage Relationships Expressing the Rate of Evaporation and Condensation in Terms of Local Interfacial Thermodynamics Properties and the Mass Accommodation Coefficient is a Subject of Significant Discussion. in This Work, We Carry Out Molecular Dynamics (MD) Simulations of Evaporation and Condensation of Fluid Ar in a Nanochannel. by Adjusting the Temperature Difference, ΔT, between the Evaporating and Condensing Surfaces, We Control the Steady-State Evaporation and Condensation Fluxes (JMD). We Find that Across a Wide ΔT Range Studied, JMD is Always in Excellent Agreement with the Prediction from the Exact Schrage Relationships. Furthermore, …

Assessment Of Multimode Spacecraft Micropropulsion Systems, Steven P. Berg, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multimode spacecraft micro propulsion systems that include a high-Thrust chemical mode and high-specific impulse electric mode are assessed with specific reference to CubeSat-sized satellite applications. Both cold-gas butane propellant and ionic liquid chemical monopropellant modes are investigated alongside pulsed plasma, electrospray, and ion electric thruster modes. These systems are studied by varying electric propulsion usage percent and calculating the payload mass fraction and thruster burn time for missions requiring 250, 500, and 1000 m/s delta-V. Systems involving chemical monopropellants have the highest payload mass fractions for a reference mission of 500 m/s delta-V and 6U-sized CubeSat, where 1U is a …

Probabilistic Analysis And Verification Framework For Adaptive Flight Control, Mario Luca Fravolini, Tansel Yucelen, Marcello Napolitano

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A crucial aspect that could facilitate the applications of adaptive control systems in aerospace applications is the development of effective validation and verification procedures. Most of the existing analysis and design frameworks for adaptive controllers are based on the Lyapunov direct method. One well-known drawback of this approach is the conservatism in the estimation of the uniform ultimate boundedness region with little practical utility. To overcome this limitation, a probabilistic framework for the design of uniform ultimate boundedness regions is proposed where uncertain parameters and adaptive controls are considered as random variables. In this framework, the design is translated into …

Plume Characterization Of Electric Solid Propellant Pulsed Microthrusters, Matthew S. Glascock, Joshua L. Rovey, Shae Williams, Jason Thrasher

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are an attractive option for propulsion because they are ignited only by an applied electric current. This leads to capabilities such as on-demand throttling and reignition in chemical combustion operation, and it lends itself to application in electric propulsion. In this work, the plasma plume created by electric solid propellant pulsed micro thrusters is investigated using a nude Faraday probe, a triple Langmuir probe, and residual gas analysis. The thrusters are tested at a vacuum level of 2 x 10-5torr. Results indicate an average plume electron temperature of 1.7 eV and a density of 1011 to 1014cm-3. …

Analytical Strip Method For Thin Cylindrical Shells, John T. Perkins

Theses and Dissertations--Civil Engineering

The Analytical Strip Method (ASM) for the analysis of thin cylindrical shells is presented in this dissertation. The system of three governing differential equations for the cylindrical shell are reduced to a single eighth order partial differential equation (PDE) in terms of a potential function. The PDE is solved as a single series form of the potential function, from which the displacement and force quantities are determined. The solution is applicable to isotropic, generally orthotropic, and laminated shells. Cylinders may have simply supported edges, clamped edges, free edges, or edges supported by isotropic beams. The cylindrical shell can be stiffened …

Data-Driven Adaptive Reynolds-Averaged Navier-Stokes K - Ω Models For Turbulent Flow-Field Simulations, Zhiyong Li

Theses and Dissertations--Mechanical and Aerospace Engineering

The data-driven adaptive algorithms are explored as a means of increasing the accuracy of Reynolds-averaged turbulence models. This dissertation presents two new data-driven adaptive computational models for simulating turbulent flow, where partial-but-incomplete measurement data is available. These models automatically adjust (i.e., adapts) the closure coefficients of the Reynolds-averaged Navier-Stokes (RANS) k-ω turbulence equations to improve agreement between the simulated flow and a set of prescribed measurement data.

The first approach is the data-driven adaptive RANS k-ω (D-DARK) model. It is validated with three canonical flow geometries: pipe flow, the backward-facing step, and flow around an airfoil. For all 3 test …

Autonomous Quadrotor Collision Avoidance And Destination Seeking In A Gps-Denied Environment, Thomas C. Kirven

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis presents a real-time autonomous guidance and control method for a quadrotor in a GPS-denied environment. The quadrotor autonomously seeks a destination while it avoids obstacles whose shape and position are initially unknown. We implement the obstacle avoidance and destination seeking methods using off-the-shelf sensors, including a vision-sensing camera. The vision-sensing camera detects the positions of points on the surface of obstacles. We use this obstacle position data and a potential-field method to generate velocity commands. We present a backstepping controller that uses the velocity commands to generate the quadrotor's control inputs. In indoor experiments, we demonstrate that the …

Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green

Mechanical and Materials Engineering Faculty Publications and Presentations

This year marks the 55th anniversary of the first fluid physics experiment performed aboard a spacecraft during the Mercury-Atlas 7 mission. Since then, NASA has conducted over 80 fluids physics experiments aboard a variety of spacecraft, many of which have enhanced the understanding of large-length-scale capillary phenomena relevant to liquid management in the weightless state. As both celebration and demonstration, the Mercury-Atlas 7 fluids experiment is revisited in light of the current understanding of large-length-scale capillary fluidics. Employing a modern numerical tool, a rich variety of experimental outcomes are discovered that were not observed during the flight experiment. Interestingly, experimental …

Wrinkling Of Functionally Graded Sandwich Structures Subject To Biaxial And In-Plane Shear Loads, Harold Costa

Masters Theses

"Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper [1] where a several-fold increase in the wrinkling stress was observed, without a significant weight penalty, using a stiffer core adjacent to the facings. In the present paper wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading and the core is arbitrary graded through-the-thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core and the verification that functional grading …