Mechanical Engineering Commons^™

Investigation Of Exothermic Reaction Dynamics Via Computational Fluid Dynamics Coupled With A Feedback Controller, Siusan Choi

Mechanical and Aerospace Engineering Dissertations - Archive

The control of reaction temperature under continuous flow conditions is important in a variety of chemical manufacturing industries. For many reactions, operating at off-design temperatures can result in the production of undesired products, reduced feedstock conversion and, in some cases, reduced catalyst lifetime. In many exothermic reactions, maintaining a desired set point temperature at high reactant flow rates becomes challenging if the chemical kinetics exhibit highly non-linear behavior. In these situations, the interaction between commonly used linear controllers and the physical system can lead to unexpected dynamic response and undesired swings in reaction temperature. In this research, a computational model …

General Solutions To Temperature Distribution In Orthotropic Systems Subject To Variable Heat Transfer And Biological Systems During Bioheat Transfer, Daipayan Sakar

Mechanical and Aerospace Engineering Dissertations - Archive

Bioheat transfer is the phenomenon of heat transfer in biological systems where the dominant modes of heat transfer are conduction and advection. Other factors such as rate of metabolism that are unique to biological systems contribute significantly towards bioheat transfer. In the present work, the Pennes bioheat equation has been solved for a multilayer system to derive steady state and transient temperature solutions in the multilayer skin tissue with a tumor. In nanoparticle based hyperthermia therapy, the body temperature elevates from the physiological core body temperature, 37 deg. C. Analytical solutions for three different therapeutic techniques have been developed to …

Integration Of A Portfolio-Based Approach To Evaluate Aerospace R&D Problem Formulation Into A Parametric Synthesis Tool, Amit R. Oza

Mechanical and Aerospace Engineering Dissertations - Archive

The focus of this study is to improve R&D effectiveness towards aerospace and defense planning in the early stages of the product development lifecycle. Emphasis is on: correct formulation of a decision problem, with special attention to account for data relationships between the individual design problem and the system capability required to size the aircraft, understanding of the meaning of the acquisition strategy objective and subjective data requirements that are required to arrive at a balanced analysis and/or “correct” mix of technology projects, understanding the meaning of the outputs that can be created from the technology analysis, and methods the …

Performance Analysis, Dynamic Simulation And Control Of Mass-Actuated Airplane, Sukru Akif Erturk

Mechanical and Aerospace Engineering Dissertations - Archive

The control of space, aerial and underwater vehicles requires moment generation mechanisms to change their orientation. In addition to or in place of conventional moment generation actuators, internally moving-mass actuation has been proposed and/or used for such vehicles. The primary principle for mass-actuation is to reposition gravitational force to change the associated moment while the secondary effect may come from the inertial force due to the motion of the masses. Recent development/miniaturization in flight control sensor, computing and actuation, and electric motors and expansion of applications for small UAV (Unmanned Aerial Vehicle) offer a potential for implementation of internal mass-actuation …

Complex Multidisciplinary System Composition For Aerospace Vehicle Conceptual Design, Alexis R. Gonzalez

Mechanical and Aerospace Engineering Dissertations - Archive

Although, there exists a vast amount of work concerning the analysis, design, integration of aerospace vehicle systems, there is no standard for how this data and knowledge should be combined in order to create a synthesis system. Each institution creating a synthesis system has in house vehicle and hardware components they are attempting to model and proprietary methods with which to model them. This leads to the fact that synthesis systems begin as one-off creations meant to answer a specific problem. As the scope of the synthesis system grows to encompass more and more problems, so does its size and …

Experimental Investigation Of Methane Reformer With A Continuous Flow Reactor, Xiao Zhang

Mechanical and Aerospace Engineering Dissertations - Archive

Over the decades, seeking for an alternative energy source has been more and more significant because of increasing demand with rapid industry expansion. Liquid hydrocarbon from Fischer-Tropsch process is considered as an alternative fuel source because the product is considered as subtle for petroleum-derived. Syngas as feedstock for F-T process plays a crucial role in liquid hydrocarbon production. Among several commercial and experiment technologies, the most common technology for syngas production is natural gas reforming. The product from reforming process has proper carbon monoxide/hydrogen ratio for direct application in F-T synthesis. Meanwhile, combined carbon dioxide into reforming reaction has attracted …

Complex Multidisciplinary Systems Decomposition For Aerospace Vehicle Conceptual Design And Technology Acquisition, Amen Omoragbon

Mechanical and Aerospace Engineering Dissertations - Archive

Although, the Aerospace and Defense (A&D) industry is a significant contributor to the United States’ economy, national prestige and national security, it experiences significant cost and schedule overruns. This problem is related to the differences between technology acquisition assessments and aerospace vehicle conceptual design. Acquisition assessments evaluate broad sets of alternatives with mostly qualitative techniques, while conceptual design tools evaluate narrow set of alternatives with multidisciplinary tools. In order for these two fields to communicate effectively, a common platform for both concerns is desired. This research is an original contribution to a three-part solution to this problem. It discusses the …

The Effects Of Temperature And Relative Humidity On Exposure Of Legacy And Future Technology Hardware, Under Real Data Center Conditions In An Ansi/Isa Classified G2 Environment, Oluwaseun Michael Awe

Mechanical and Aerospace Engineering Dissertations - Archive

It is well established that it is safe to operate information technology (IT) equipment in a G1 classified contaminant severity level when operating within specified ASHRAE recommended and allowable limits in an air-side economizer data center. This is basis for which electronic equipment manufacturers provide warranty for their products. IT equipment manufacturers in the US now requires data centers operators to demonstrate that they meet all the specified conditions consistently before fulfilling warranty equipment failure. This places limitation to where data center utilizing air-side economizer can be located. In order to determine the reliability of electronic hardware in higher severity …

Analysis Of Composite Beams With Airfoil Cross-Sections With I-Section Stiffener Under Tension And Bi-Directional Moments, Peter Louis Leboulluec

Mechanical and Aerospace Engineering Dissertations - Archive

Annual wind power generation capacity in the US has increased from 3 gigawatts in 2000 to 61 gigawatts in 2013 and is on track to fulfill 20% of projected U.S. electricity needs (305 gigawatts) by 2030. To enable the increase in electricity generation of wind turbines, longer blades are being designed which require improved engineered blades to handle higher loads. Thus, the wind turbine industry is turning to the use of carbon-epoxy composite materials to take advantage of their low weight yet high strength ratio and improved fatigue resistance. Current analyses to design turbine blades utilize either Finite Element Analysis …

Thermal Energy Storage For Expanded Use Of Data Center Indirect/Direct Evaporative Cooling, Jefferey Luttrell

Mechanical and Aerospace Engineering Dissertations - Archive

Computer cooling system design evolved over time with goals of increasing efficiency and decreasing cost. Early computers were essentially hand-built and very expensive. Reliable operation required aggressive cooling to maintain acceptable component temperatures and this was achieved with relatively low ventilation air temperatures. With time, the scale of operations increased to the point that operating cost began to strongly influence design decisions. Computer room air conditioners consumed substantial amounts of electrical power, in some situations almost as much power as the computer equipment. One cost saving idea used outside air when the ambient temperature fell below the normal cooling supply …

Understanding The Alchemilla Leaf And Its Hydrophobicity, Atul Mohandas Kootathil

Mechanical and Aerospace Engineering Theses - Archive

The Alchemilla leaf has been well known and studied frequently for its hydrophobic ability. However, much difficulty has been met in replicating its microstructure for hydrophobic applications. Also, not much experimental data was found on the behavior of leaf’s microstructure. Gathering information from experimental results may provide new understanding of its wetting properties before attempting to mimetic its wetting behavior. In this research, the focus is to detail the observed solid-water-air interaction on Alchemilla leaf by simulating condensation, evaporation and rainfall conditions, which are the common ways that a plant may interact with water drops in nature. Documenting these observations …

Attitude Stabilization Of Spacecraft Using Moving Masses, Juran Hwang

Mechanical and Aerospace Engineering Theses - Archive

This research investigates the ability of stabilizing spacecraft rotational motion by internal mass actuation. The mass actuation mechanism consists of three internal masses placed along the three axes at some offset distance that can move to induce inertial forces and moments and change the inertia matrix and center of mass. A set of nonlinear equations of motion are developed to model the motion, both orbital and rotational dynamics and kinematics, of a spacecraft with mass and inertial variation due to internal mass actuation, under the gravitational field of Earth. The equations inherently include the inertia effect of the mass motion …

Developing And Validating Energy Models For Indirect And Direct Evaporative Cooling Used In Datacenters, Rajesh Kasukurthy

Mechanical and Aerospace Engineering Theses - Archive

In the present day to day life, Internet of things is everything, i.e., we need internet and telecommunication for almost every task of our life and these require data from data centers. These data centers provide various facilities like data processing, storage, and transmission, and maintenance, operations etc., for performing these tasks, a huge amount of power is consumed by the data center, which in turn generates large amount of heat. As these data centers are to be made operational throughout the year, cooling of data centers is of utmost importance. These cooling systems like air conditioners, economizers and evaporative …

Mechanical Property Evaluation Of Magnesium Rich Primer Coating System Over Aa 2024 T-3 Aluminum Alloy By Nano-Inedntation, Hongyi Qu

Mechanical and Aerospace Engineering Theses - Archive

Aluminum alloy is widely used as a major structural material, such as for wing and fuselage, in aerospace industry. Corrosion is the most insidious form of damage to aluminum alloy, which can cause aircraft structure damage and related safety issue. Coating is generally used in industry to protect metal structure. An alternative to present toxic chromium primer coating system, magnesium rich primer (MgRP) has been developed to protect AA 2024 T-3. Studies have demonstrated the anti-corrosion performance of MgRP. However, the interlayer material heterogeneity can affect the mechanical properties of coating such as modulus, hardness and interfacial behavior. In the …

Active Torque Vectoring For All Wheel Drive Fsae Electric Car, Vikas Tukaram T Pawar

Mechanical and Aerospace Engineering Theses - Archive

UTA Racing is known for building well-engineered FSAE racecars. This year team is building, its first electric car by using AWD in-wheel motor concept car E-16. All wheel drive electric vehicles has an ability to apply instantaneous torque to all four wheels permit increased car performance. An ‘Active Model Based Torque Vectoring System controller’ is designed to realize this objective. The controller was designed to replicate three electronically controlled LSD's on an all-wheel drive platform with different control strategies. This was achieved based on the principal of distributing total driver requested torque between wheels, equivalent to the percentage of the …

Guidance Navigation And Control Implementation For Unmanned Ground Vehicle Using Ni-Myrio, Ishwarya Srinivasan

Mechanical and Aerospace Engineering Theses - Archive

This research effort aims at investigating alternative real-time implementation software and hardware for Guidance, Navigation and Control (GNC) algorithms for an Unmanned Ground Vehicle (UGV). A GNC algorithm was previously developed for a skid-steered tracked UGV to go through assigned waypoints based on encoder counts. The UGV has two electric motors driving the tracks on each side and two encoders providing the speeds of the drive wheels. This algorithm was implemented using Matlab/Simulink-based model running on a mini computer, interfacing with the electric motors and encoders through a specialty control board. This current effort is to implement the same GNC …

Fitting B-Splines Curves To Coarse Data Cloud Using Modified Squared Distance Minimization Method, Vinay Vivek Mhala

Mechanical and Aerospace Engineering Theses - Archive

Additive manufacturing has made us realize that we can fabricate complex shapes that were difficult to manufacture with subtractive processes. Topology optimizations results have complex shapes and have rough surfaces which are difficult to manufacture even by additive manufacturing. To automate the process of converting rough surfaces into smooth surfaces for the benefit of manufacturability would be very desirable. Computing curve segments to approximate point cloud data that represents rough surfaces and then lofting it to have a smooth surface seems to be a promising methodology to achieve automation. We implement B-spline formulation along with Pottmann’s iterative method based on …

Study Of Crack Propagation Under Thermal Loading On A 3d Tsv Package, Subramanian R. Gowtham

Mechanical and Aerospace Engineering Theses - Archive

Today, there is a revolution in going for miniaturization in size of electronic packages. More thinner, lighter and complex packages are in use for almost every electronic device. This initiation was taken to the next level and gives us a whole new ideology called 3D packaging. Currently, 3D packaging is the on-going research in almost all the electronic packaging related industries. 3D package uses Through Silicon Via (TSV) technology that gained momentum in the development and helped packaging system for significant miniaturization and power reduction, which result in increased performance. However, the reliability assessment is needed to evaluate the critical …

Embedding Antenna Shear/Pressure Sensors In Prosthetic Liner Material, Shahanavaz Eilbeigi

Mechanical and Aerospace Engineering Theses - Archive

Published surveys indicated that 40-60% of prosthesis users experience discomfort and skin problems. These studies highlighted the needs for enhanced prosthetic performance and fit. It is extremely difficult to address these problems due to two reasons: first, ambulation create varying areas of shear and pressure on the residual limb, but it is not clear which shear/pressure combinations are acceptable and what is the safe stress level for users. In addition, the volume of the residual limb changes throughout the day and activity level. Therefore, there is a strong need to develop a light, thin, flexible, and wirelessly interrogated sensor for …

Fundamental Principles Of Tremor Propagation In The Upper Limb, Andrew Doran Davidson

Theses and Dissertations

Although tremor is the most common movement disorder, there exist few effective tremor-suppressing devices, in part because the characteristics of tremor throughout the upper limb are unknown. To clarify, optimally suppressing tremor requires a knowledge of the mechanical origin, propagation, and distribution of tremor throughout the upper limb. Here we present the first systematic investigation of how tremor propagates between the shoulder, elbow, forearm, and wrist. We simulated tremor propagation using a linear, time-invariant, lumped-parameter musculoskeletal model relating joint torques and the resulting joint displacements. The model focused on the seven main degrees of freedom (DOF) from the shoulder to …

Delay-Independent Stability Analysis Of Linear Time-Delay Systems Based On Frequency, Xianwei Li, Huijun Gao, Keqin Gu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper studies strong delay-independent stability of linear time-invariant systems. It is known that delay-independent stability of time-delay systems is equivalent to some frequency-dependent linear matrix inequalities. To reduce or eliminate conservatism of stability criteria, the frequency domain is discretized into several sub-intervals, and piecewise constant Lyapunov matrices are employed to analyze the frequency-dependent stability condition. Applying the generalized Kalman–Yakubovich–Popov lemma, new necessary and sufficient criteria are then obtained for strong delay-independent stability of systems with a single delay. The effectiveness of the proposed method is illustrated by a numerical example.

Total Temperature Measurement At Pulse Detonation Engine Exhaust, Ninad Ramesh Kawle

Mechanical and Aerospace Engineering Theses - Archive

Pulse detonation engines (PDEs) are being studied in recent years as a potential means of power production. In PDEs, a supersonically travelling detonation wave traverses through the detonation tube. Total temperature of the exhaust of the PDE is not a well-known parameter. The objective of the research was to calibrate and employ miniature type E thermocouples for exhaust temperature measurement of the PDE. The probe making process along with the calibration techniques for AWG 20, AWG 24 and AWG 50 thermocouples are discussed at length. The time constants for thermocouples were determined. Reactive mixture containing hydrogen and oxygen was used …

Method Of Characteristics Verification Of Inverse Frequency Model Of Turbulent Pipe Flow Transients, Mohammad Saifullah Mohammad Zafar Shaikh

Mechanical and Aerospace Engineering Theses - Archive

Pressure transients in pipes with turbulent flow have classically been simulated using numerical techniques such as the method of characteristics. An alternative method utilizing an inverse frequency algorithm has recently been introduced for smooth pipe and determined to be computationally fast compared to the method of characteristics and in some cases more accurate. In addition, comparisons with experimental water hammer data has verified that the inverse frequency method is accurate out to Reynolds numbers of 15,800. This thesis investigates a comparison or the inverse frequency and method of characteristics methods for Reynolds numbers out to 200,000 for smooth pipes.

A Novel Stress Analysis Method For Laminated Composite Stiffener With Asymmetric Z-Section Under Mechanical And Thermal Loading Conditions, Sidhant Singh

Mechanical and Aerospace Engineering Theses - Archive

Composites structures are being used as load carrying members in latest aircrafts and performance automobiles, the design validation for such structures can be a time consuming and expensive process, if done by testing. Validation of a structure by analysis saves time and money for a design process and validation by analysis can be done by comparing the analytical solution with the finite element analysis of the structure, which requires availability of analytical expressions for every cross-sectional arrangement of the structural members. This research focuses on stress analysis of laminated composite stiffener with asymmetric Z-sections, where closed form analytical expressions are …

Second Law Of Thermodynamics Analysis Of An Internal Combustion Engine Fueled With Methane, Muataz Abotabik

Masters Theses

The second law of thermodynamics is a powerful tool for calculating the amount of energy that can be converted to work (i.e., the exergy or availability of a system), which cannot be predicted using the first law. The objectives of this research project are to quantify the availability during the compression, combustion and expansion processes of a spark-ignited engine fueled with methane; and to highlight differences in the thermo-mechanical availability of the ideal and spark-ignition (SI) engine cycles. A cooperative single-cylinder research engine was used to measure the data required for availability analysis at equivalence ratios ranging between 0.83 and …

Determining Energy Output In Manual And Automated Solar Arrays, James K. Ayres

Honors Theses

The scope for the project was to design and construct a system that could be used to both manually and automatically track the sun using solar panels to demonstrate engineering principles for classroom and laboratory experiments at both the primary and secondary education levels. For ease of demonstration, a manual and automatic tracker was designed for the experiment. Using a standard camera tripod, the solar panels were attached to fabricated mounts to allow for omnidirectional movement. For the automated, or active tracker, an Ardunio Uno microcontroller was used in conjunction with two 180˚ servos to adjust the active tracker solar …

Strain Energy Absorption Corresponds To Decreased Incidence Of Ventricular Fibrillation In A Commotio Cordis Model, Kayt E. Frisch, Mark S. Link, John Van Weelden

Faculty Work Comprehensive List

A healthy teenage boy is playing high school baseball, when he is struck in the chest by the ball; minutes later, his heart is experiencing ventricular fibrillation (VF) and the only way to resuscitate him is to use a defibrillator. This phenomenon, is known as Commotio Cordis (CC), and occurs as many as 20 times each year in the United States. CC most frequently occurs in sports with small balls (e.g. baseball or lacrosse) and requires a specific set of circumstances–a projectile with a certain amount of energy that impacts directly over the left ventricle of the heart during a …

Parameter Estimation For Hvac System Models From Standard Test Data, Hannah Luthman

Boise State University Theses and Dissertations

Nearly all cooling systems, and an increasing proportion of heating systems, utilize the vapor compression cycle (VCC) to provide and remove heat from conditioned spaces. Even though the application of VCC’s throughout the building environment is ubiquitous, effective and accessible models of the performance of these systems remains elusive. Such models could be important tools for VCC designers, building designers and building energy managers as well as those who are attempting to optimize building energy performance through the use of model-based control systems.

Strides have been made in developing lumped parameter models for VCC’s. In spite of these contributions, widespread …

Packing Sheet Materials Into Cylinders And Prisms Using Origami-Based Approaches, Jared Thomas Bruton

Theses and Dissertations

Packing sheet materials into cylinders and prisms using Origami-based approaches (Soft Origami or traditional Origami) is of interest in fields where sheet materials need folded into cylinders or prisms. Fully-dense packing has application in fields where a sheet material is to be folded with minimal gaps into a cylinder or prism. Partially-dense packing is applicable to fields where gaps are required between packed surfaces or where hollow volumes are to be filled, such as in fluid filter design. Soft Origami is explored as a method for folding soft-sheet materials into fully-dense cylinders. Two fold patterns, the "flasher'' and the "inverted-cone …

Modeling The Impact Of Battery Degradation Within Lifecycle Cost Based Design Optimization Of Heavy-Duty Hybrid Electric Vehicles, Ashish P. Vora

Open Access Dissertations

The optimal design of hybrid electric vehicle (HEV) powertrains from a systems perspective is critical to realize the maximum benefits for a given application. This is particularly true in the heavy-duty vehicle space where the major challenges are: (i) greater emphasis on economic viability, (ii) reluctance to take on risk associated with new technologies, and (iii) numerous diverse applications that preclude a one-size-fits-all approach to hybrid-electric powertrain design. Past studies on HEV powertrain design have either ignored battery degradation, or failed to holistically capture its impact from a lifecycle cost perspective. The focus of this effort is the development of …