Aerospace Engineering Commons^™

Undergraduate Examination Of Pollutant Aerosols In Earth's Atmosphere, Matthew Toon, Tyler Weenig, Zach Collins, Fred Davis, Christopher Maughan, Kyle Strong, Kim Nielsen

Utah Space Grant Consortium

Air pollution can result from both natural and human-caused actions. Natural pollutants may result from events like: forest fires, volcanic eruptions, wind erosion, natural radioactivity, etc. Human pollutants can result from: toxic emissions from vehicles or manufacturing plants, burning fossil fuels, household or farming chemicals released into the air, second hand smoke from tobacco users, etc.

Pollution can obviously have an extremely negative effect on the air quality that we as humans, as well as all living creatures, breathe and depend on for life. Pollution can also negatively impact water and soil by introducing toxins into these resources needed for …

Hapcad, Prototype For The Gaspacs Aeroboom Deployment, Jan J. Sojka, Get Away Special Team

Utah Space Grant Consortium

This past summer the Utah State University Get Away Special Microgravity Research Team tested several of their prototypes on high altitude balloons. They had a total of four balloon launches were they collected a variety of data. Their primary purpose was to test their passive stabilization mechanism called the Aeroboom.

Byu Passive Inspection Cubesats (Pics), David Long, Passive Inspection Cubesat Usip Team

Utah Space Grant Consortium

The BYU Passive Inspection CubeSat (PICS) is the first stage of a series of technology demonstration missions for spacecraft capable of performing inspection, maintenance and assembly on another spacecraft. PICS will demonstrate ultrafast booting and power-up operation of system electronics and the low-risk inspection of the exterior of a spacecraft by a passive, inexpensive flyaway probe. Two flight systems deployed simultaneously will enable the collection of image data from each other as well as the parent spacecraft. Both units include spherical imaging capability using a camera on each face of the 10 cm cube so that attitude control is not …

Study Of Knowledge-Based System (Kbs) And Decision Making Methodologies In Materials Selection For Lightweight Aircraft Metallic Structures, Pashupati R. Adhikari, Reza Mirshams

Journal of Applied Science & Engineering Technology

This paper presents an overview of knowledge-based system (KBS) in the context of decision making methodologies used in materials selection for the design of light weight aircraft metallic structures. Overall aircraft weight reduction means substantially less fuel consumption and better efficiency. Part of the solution to this problem is to find a way to reduce overall weight of metallic structures in the aircraft. Two distinct multiple criteria decision making (MCDM) methodologies are presented with examples featuring a set of short-listed materials suitable in the design of the structures. Pre-defined constraint values, mainly mechanical properties, are employed as relevant attributes satisfying …

Interactions Of A Co-Rotating Vortex Pair At Multiple Offsets, Kyle Forster, Tracie Barber, Sammy Diasinos, Graham Doig

Aerospace Engineering

Two NACA0012 vanes at various lateral offsets were investigated by wind tunnel testing to observe the interactions between the streamwise vortices. The vanes were separated by nine chord lengths in the streamwise direction to allow the upstream vortex to impact on the downstream geometry. These vanes were evaluated at an angle of incidence of 8° and a Reynolds number of 7 x 10⁴ using particle image velocimetry. A helical motion of the vortices was observed, with rotational rate increasing as the offset was reduced to the point of vortex merging. Downstream meandering of the weaker vortex was found to …

An Exact Analysis For Four-Order Acousto-Optic Bragg Diffraction Which Incorporates Both Incident Light Angle And Sound Frequency Dependencies, Adeyinka Sunday Ademola

Electrical Engineering Theses

This thesis extends the prior work which produced an exact solution to the four-order acousto-optic (AO) Bragg cell with assumed fixed center frequency and with exact Bragg angle incident light. The extension predicts the model that incorporates the dependencies of both the input angle of light and the sound frequency. Specifically, a generalized 4^th order linear differential equation (DE), is developed from a simultaneous analysis of four coupled AO system of DEs. Through standard methods, the characteristic roots, which requires solving a quartic equation, is produced. Subsequently, a derived system of homogeneous solutions, which absorbs the roots obtained using …

Gain Scheduling Controller For Aircraft With Mass And Inertia Variation, Eunyoung Kim

Mechanical and Aerospace Engineering Dissertations - Archive

Robustness is one of the main control design requirements for aircraft control.Robustness is sought in the stability and performance of closed loop system against various factors such as disturbance, measurement error, modeling error or un-modeled dynamics. In aircraft control design, it is common to assume that the mass and inertia properties of aircraft are constant. Further, aircraft is assumed to have symmetry inits mass distribution relative to its mid-vertical plane. There are, however, cases where the aircraft mass changes rapidly, most notably in aerial refueling operation.The mass change also results in changes in the inertia matrix. An aircraft may also …

On Space Program Planning: Quantifying The Effects Of Spacefaring Goals And Strategies On The Solution Space Of Feasible Programs, Mark Douglas Coley

Mechanical and Aerospace Engineering Dissertations - Archive

An organization's space program represents the coalescence of top-level goals and strategies with the specific, lower-level combinations of mission architectures, hardware, and technology. High costs and long lead times necessitate substantial planning and key decisions to be made years, possibly decades, in advance. Unfortunately, the methods and processes available for planning have historically been unable to provide decision-makers with objective, quantitative information from both the top and lower levels of the space program. Instead, decision-makers are forced to turn to top-level, qualitative assessments, disconnected from any of the fundamental, technical details, where inconsistent comparisons and secondary effects often become the …

Studying Effects Of Adhesive Layer On Electrical Signals Of Piezoelectric Transducer Bonded With Structure, Md Mazharul Islam

Mechanical and Aerospace Engineering Dissertations - Archive

Piezoelectric wafer active sensors (PWAS) are the most attractive transducers for guided-wave or ultrasound based structural health monitoring (SHM) because of their light weight and compact size. In order to excite guided waves in a structure, the PWASs are usually bonded on the surface of the structure by adhesive materials. The electrical signal applied to the surface bonded PWAS is converted to mechanical deformation of the PWAS which in turn is transferred to the structure through the adhesive layer. Thus, understanding the effects of the adhesive layer on the electrical response of the PWAS enables us to optimize the mechanical …

Nonlinear Model Predictive Control For Cooperative Control And Estimation, Pengkai Ru

Mechanical and Aerospace Engineering Dissertations - Archive

Recent advances in computational power have made it possible to do expensive online computations for control systems. It is becoming more realistic to perform computationally intensive optimization schemes online on systems that are not intrinsically stable and/or have very small time constants. Being one of the most important optimization based control approaches, model predictive control (MPC) has attracted a lot of interest from the research community due to its natural ability to incorporate constraints into its control formulation. Linear MPC has been well researched and its stability can be guaranteed in the majority of its application scenarios. However, one issue …

Characterization Of Vertically Split Distribution-Wet Cooling Media Used In Data Centers, Mullaivendhan Varadharasan

Mechanical and Aerospace Engineering Theses - Archive

Data Centers houses substantial number of information technology (IT) equipment like computer servers and storage modules associated with various electronic components which consume high volume of electricity. The IT equipment in data center housing keeps dissipates heat energy as it is constantly running day and night. To keep the data center environment under thermally control and to favor the reliability of electronic components, we need to adopt a cooling technique which aids the module level cooling, with due consideration of the size of the data center and its geographical location. One of the adopted cooling technique in data center thermal …

Composite Plate Optimization With Structural And Manufacturing Constraints, Deepak Polaki

Mechanical and Aerospace Engineering Theses - Archive

This is a design optimization study that focuses on the value of free size optimization technology on composite structures which incorporates realistic structural requirements and practical manufacturing limitations to achieve an iterative design with effective structural performance. To detail a study on such practical implementation, a sample structure is required. A rectangular composite laminate with a central hole cutout is considered for this study and is designed using finite elemental tools which includes compression, tension and shear loading conditions with load reactions at bolted joints and buckling stability. Free size optimization and size optimization are used in this study to …

Reliability Assessment Of Solder Joint Using Bga Package – Megtron 6 Versus Fr4 Printed Circuit Boards, Mugdha Anish Chaudhari

Mechanical and Aerospace Engineering Theses - Archive

When it comes to the mechanical and electrical seam of the Printed Circuit Board (PCB) and package, reliability of the board plays a major impact on PCB. As the frequency increases, losses in signals increase. This necessitates the use of new materials for such applications. Nelco 4000-13EPSI, Rogers 4350B, Panasonic Megtron 6 are few high-speed materials used. Studies have shown that Megtron 6 has the least dielectric losses so far, low transmission loss, high heat resistance and has low weight loss than the FR-4 boards. With an increasing demand for high performance, reliability and lower costs, the field of electronic …

Solder Joints Design Optimization Of Qfn Packages For Different Boards By Investigating Solder Joint Reliability, Rishikesh Vilas Tendulkar

Mechanical and Aerospace Engineering Theses - Archive

Quad Flat No-lead package (QFN) is one of the most cutting-edge technologies emerged in the market, exhibiting high performance and efficiency with unparalleled cost effectiveness. QFN, a leadless package, is an ideal choice for applications where size, weight thermal and electrical characteristics are critical, particularly in mobile and handheld devices. Applications like automotive, defense and high current circuits require the package to be mounted on thick printed circuit boards (PCB). The motivation of this work is to understand the effect of design variations of solder joints affecting reliability and optimize the solder package to improve reliability for application on different …

An Improved Method For Measurement Of Radial Thermal Conductivity Of Cylindrical Bodies, Salwa Shaik

Mechanical and Aerospace Engineering Theses - Archive

Li-ion cells are ubiquitously found in day to day electronic devices due to their high power density storage capacity. These batteries are known to exhibit sharp reduction in performance at high temperature. Due to this, several attempts have been made in the past to measure thermal properties of the Li-ion cell. This work improves upon past measurements by showing that heat loss during measurements is non-negligible, and by developing an analytical model to account for such heat loss. Experimental measurements carried out on multiple materials demonstrate non-negligible heat loss. When accounted analytically, these data result in thermal conductivity values that …

Electro-Pneumatic Shifting And Servo Control Of A Clutch For A Fsae Racecar, Rahul Janardhan Chalmela

Mechanical and Aerospace Engineering Theses - Archive

FSAE is an international student design competition held by SAE International where students design, build and compete in static events like cost, design and dynamic events ranging from acceleration, autocross to endurance. UTA Racing has been a part of FSAE since 1982 and have been using a mechanical design for their shifter and clutch since then. This year for the 2017 design competition an electro-pneumatic system is developed to replace the mechanical system. This system consists of pneumatic cylinders controlling a sequential shifter and a servo clutch. The cylinders are controlled using direction control valves, these receive their signals from …

Rack Level Study Of Hybrid Cooled Servers Using Warm Water Cooling With Variable Pumping For Centralized Coolant System, Chinmay Sanjay Kshirsagar

Mechanical and Aerospace Engineering Theses - Archive

As the worldwide demand for the data centers grows, so does the size and load placed on data centers which leads to the applied constraints on power and space available to the operator. Cooling power consumption is a major contributor of the total energy consumption of the system. In the process of optimization of cooling energy consumption per performance unit, liquid cooling technology has emerged as one of the most viable solutions. In this rack level study, 2OU (Open U) hybrid cooled web servers are tested for an evaluation of warm water cooling in centralized coolant system. Effects of higher …

Load Carrying Capacity Management Of Compound Anisotropic Composite Rings Under External Pressure, Salman Bakhrayba

Mechanical and Aerospace Engineering Theses - Archive

Composites have much higher strength than conventional materials such as steel. This makes it attractive to replace heavy loaded structural elements, made traditionally from steel, by elements made from composites. However, it is not a trivial task for statically indeterminate structures due to anisotropy of elastic and strength properties of composites. Present investigation is done for a ring subjected to external load. Such rings are used as bulkheads in many applications. Dependence of ultimate external pressure on thickness of the ring is nonlinear one. It is related to non-uniformity of distribution of circumferential stresses, with anisotropy of material, with set …

Comparative Study Of Viscoelastic Modeling And Linear Modeling For Wafer Level Chip Scale Package Under Drop Impact, Navya Sri Reddy Kasi Reddy

Mechanical and Aerospace Engineering Theses - Archive

Wafer level chip scale packages are one the preferred choice in the electronic industry to meet the need of new miniaturization of the recent devices. It has high efficiency in packaging and has low cost. On the other hand, the drop impact failure is one of the growing risk in day to day use of the portable devices. Therefore, to ensure product quality and to integrate more complicated functionality in these devices comprehensive reliability tests need to be performed before delivering the product. Accelerated thermal cycling, drop testing and power cycling are some accepted test methods used to access board …

A Comparative Study Of Wooden And Composite Crossarm Of An Electric Utility Pole, Amith Venkatesh

Mechanical and Aerospace Engineering Theses - Archive

Currently, most of the crossarms existing in the nation are made of wood. However, wood has a set of negative features like shorter life span due to environmental cracking, damages by insects and birds. Secondly, an insufficient strength and stiffness which is compensated either by increasing the cross-section or by reducing the span between two poles. Also, it’s reduced insulating property in case of high humidity of air which can be accounted to its hygroscopic behavior. Replacement of wooden crossarms by composite crossarms is a known solution to many problems. However, the existing projects are far from optimal. Present investigation …