Aerospace Engineering Commons^™

Liquid Cooling Of A High-Power Multi-Chip Module Using A Sectioned Cold Plate, Ananthavijayan Sridhar

Mechanical and Aerospace Engineering Theses - Archive

With the advancement in micro-fabrication techniques and high performance chips, the heat flux generated through these electronics is reaching a point where air-cooling of these devices is not efficient enough. By definition, Multi-Chip Modules (MCMs) are specialized electronic packages where multiple Integrated-Circuits (ICs) and semiconductor dies are unified onto a single substrate. Increasing advancements in ICs enable MCMs as alternate packaging finding its application in high power electronics like power generation and cooling, medical devices, lasers and, military electronics etc. Hence, liquid cooling techniques are explored as possible solutions. In this study, a high power MCM is considered and, its …

Microgravity Testing Of A Phase Change Reference On The International Space Station, T. Shane Topham, Gail E. Bingham, Harri Latvakoski, Igor Podolski, Vladimir S. Sychev, Andre Burdakin

Space Dynamics Laboratory Publications

Orbital sensors to monitor global climate change during the next decade require low drift rates for onboard thermometry, which is currently unattainable without on-orbit recalibration. Phase change materials (PCM), such as those that make up the ITS-90 standard, are seen as the most reliable references on the ground and could be good candidates for orbital recalibration. Space Dynamics Lab (SDL) has been developing miniaturized phase change references capable of deployment on an orbital blackbody for nearly a decade. To determine if and how microgravity will affect the phase transitions, SDL conducted experiments with ITS-90 standard material (gallium, Ga) on the …

Characterizing Noise Trends Of The Cross-Track Infrared Sounder (Cris), Bryce Walker, Mark Esplin, Ben Esplin, Deron Scott

Space Dynamics Laboratory Publications

Outline

• CrIS Summary

• Noise characterization process

• Noise trending results

• Recent Changes

• Conclusions

Dcgs: Image Processing, Screening, & Product Distribution Solution, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SCALABLE, CROSS-PLATFORM SOLUTION FOR NEAR REAL-TIME IMAGE PROCESSING, SCREENING, & PRODUCT DISTRIBUTION

SDL provides the Distributed Common Ground System (DCGS) community with a powerful image processing, screening, and product distribution solution by combining a ground station with the VANTAGE™ tactical intelligence software suite and the Sky Lynx data link interface hardware. This system's cost-effectiveness is achieved through the use of flexible and robust hardware configurations that enable the customer to scale the system to their DCGS program needs.

Planar Laser Induced Fluorescence Experiments And Modeling Study Of Jets In Crossflow At Various Injection Angles, Luke Thompson

Electronic Theses and Dissertations

Planar Laser Induced Fluorescence (PLIF) with acetone seeding was applied to measure the scalar fields of an axisymmetric freejet and an inclined jet-in-crossflow as applicable to film cooling. From the scalar fields, jet-mixing and trajectory characteristics were obtained. In order to validate the technique, the canonical example of a nonreacting freejet of Reynolds Numbers 900-9000 was investigated. Desired structural characteristics were observed and showed strong agreement with computational modeling. After validating the technique with the axisymmetric jet, the jet-in-crossflow was tested with various velocity ratios and jet injection angles. Results indicated the degree of wall separation for different injection angles …

Evaporative Vapor Deposition For Depositing 2d Materials, Kevin Gleason

Electronic Theses and Dissertations

The development of a new deposition technique called evaporative vapor deposition (EVD) is reported, allowing deposition and formation of atomically-thin, large area materials on arbitrary substrates. This work focuses on the highly popular monolayer material – graphene oxide (GO). A droplet of a GO solution is formed on a heated polymer substrate, and maintained at steady-state evaporation (all droplet parameters are held constant over time). The polymer substrate is laser patterned to control the droplet's contact line dynamics and the droplet's contact angle is maintained using a computer controlled syringe pump. A room temperature silicon wafer is translated through the …

Deposition Thickness Modeling And Parameter Identification For Spray Assisted Vacuum Filtration Process In Additive Manufacturing, August Mark

Electronic Theses and Dissertations

To enhance mechanical and/or electrical properties of composite materials used in additive manufacturing, nanoparticles are often time deposited to form nanocomposite layers. To customize the mechanical and/or electrical properties, the thickness of such nanocomposite layers must be precisely controlled. A thickness model of filter cakes created through a spray assisted vacuum filtration is presented in this paper, to enable the development of advanced thickness controllers. The mass transfer dynamics in the spray atomization and vacuum filtration are studied for the mass of solid particles and mass of water in differential areas, and then the thickness of a filter cake is …

Cacti- And Shorebirds-Inspired Transports Of Liquid Drops And Two Related Fog Collectors, Xin Heng

Mechanical and Aerospace Engineering Dissertations - Archive

Motivated by what has been used in cacti and shorebirds to directionally manipulate water drops, we have explored two approaches to guide the movement of liquid drops. Based on these approaches, in addition to separating oil from its mixture with water, we have further developed two fog collectors. The first fog collector has a configuration similar to its counterpart in a cactus. This collector includes a large ZnO wire and an array of small ZnO wires that are branched on the large wire. All these wires have conical shapes, whose diameters gradually increase from the tip to the root of …

Compact Deployable Antenna For Cubesat Units, Sarah Bolton, Dominic Doty, Peter Rivera

Mechanical Engineering

CubeSats are an appealing platform for space exploration due to their low build and launch costs. Due to their small size, communication rates are often severely limited, preventing missions beyond low earth orbit. A low cost, high gain, high frequency antenna is needed to extend the capabilities of CubeSats.

The goal of the project was to design and build an axisymmetric parabolic antenna that could be deployed from a 10cm x 10cm x 15cm (1.5U) volume and operate at Ka band frequencies. The design selected consisted of an expanding perimeter truss supporting a tensioned mesh reflector. The perimeter truss was …

Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade

Open Access Theses & Dissertations

Acoustic emission (AE) data attained during tensile testing of epoxy impregnated Kevlar® 49 (K/Ep) composite strands were reduced and analyzed to monitor progressive damage accumulation during the approach to tensile failure. The K/Ep material tested in this study was chosen due to its similarity to the material-of-construction used in composite overwrapped pressure vessels (COPVs) used on the NASA Space Shuttle Orbiter. Insight into the progressive microstructural degradation of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to differentiate between significant AE attributable to microstructural damage …

Analysis Of Ion Emitting Jet Structures During Ionic Liquid Electrospraying, Shawn W. Miller

Doctoral Dissertations

"The ionic liquid [Bmim][DCA] is a propellant candidate for a standalone electrospray thruster or a dual-mode propulsion system. Characterization of positive polarity ions produced by [Bmim][DCA] capillary emitters with a nominal extraction voltage of 2.0 kV within a quadrupole and time-of-flight mass spectrometers is presented along with the predictions of propulsion performance. Flow rates from 0.05 to 2.18 nL/s are used to investigate the impact variations in the flow parameter have on the electrospray plume. The retarding potential analysis reveals ions emitted from the capillary are formed below the emitter potential of 500 eV. Angular distributions indicate broadening of both …

Pulsed Inductive Plasma Studies By Spectroscopy And Internal Probe Methods, Warner C. Meeks

Doctoral Dissertations

The broad effort of the Missouri Plasmoid Experiment is to elucidate the energy conversion processes in a pulsed inductive discharge due to the presence of plasma. The test article is a 440 to 490 kHz theta-pinch (or solenoidal) geometry coil with a stored energy of around 80 joules. In this work experimental hydrogen, helium, argon and xenon data at back-fill pressures of 10 to 100 mTorr (1.3 to 133.3 Pa) are obtained and interpreted. Spectral and internal probe studies were performed on MPX Mk.I and Mk.II devices, respectively. IR spectra were acquired in the Mk.I device for argon and xenon. …

Adaptive Control For Autonomous Navigation Of Mobile Robots Considering Time Delay And Uncertainty, Stephen Kofi Armah

Dissertations

Autonomous control of mobile robots has attracted considerable attention of researchers in the areas of robotics and autonomous systems during the past decades. One of the goals in the field of mobile robotics is development of platforms that robustly operate in given, partially unknown, or unpredictable environments and offer desired services to humans. Autonomous mobile robots need to be equipped with effective, robust and/or adaptive, navigation control systems. In spite of enormous reported work on autonomous navigation control systems for mobile robots, achieving the goal above is still an open problem. Robustness and reliability of the controlled system can always …

Topology Optimization For Thin Walled Structures Utilizing Simp Method By Additive Manufacturing Using Optimized Conditions, Sajith Anantharaman

Mechanical and Aerospace Engineering Theses - Archive

The objective of this research is to manufacture topology optimized structure by additive manufacturing. Topology Optimization is a method of structural optimization which gives the optimum material distribution in a design domain. This material distribution is then manufactured by additive manufacturing. Additive manufacturing can manufacture complex shapes quite easily since it works by layer-by-layer. This is an on-going field of research and not many optimization algorithms make use of the advantages of additive manufacturing. Numerous researches are done in the field of optimization which are directed towards Homogenization and Solid Isotropic material with Penalization (SIMP). But most of the methods …

Autoignition Behavior Of Synthetic Alternative Jet Fuels: An Examination Of Chemical Composition Effects On Ignition Delays At Low To Intermediate Temperatures, Daniel Valco, Gerald Gentz, Casey Allen, Meredith Colket, Tim Edwards, Sandeep Gowdagiri, Matthew A. Oehlschlaeger, Elisa Toulson, Tonghun Lee

United States Air Force: Publications

The autoignition characteristics of military aviation fuels (JP-5 and JP-8), proposed camelina-derived hydroprocessed renewable jet fuel replacements (HRJ-8 and HRJ-5), Fischer–Tropsch fuels (Shell and Sasol), three Sasol isoparaffinic solvents, as well as 50/50 volumetric blends of the alternative fuels with the conventional fuels are examined. Experiments were conducted in a rapid compression machine and shock tube at compressed temperatures of 625 K ≤ Tc ≤ 1000 K, a compressed pressure of 20 bar, and under stoichiometric and lean conditions. Several implicit properties of the alternative fuels prompted a study of the influence of chemical composition on autoignition, including the influence …

Discrete-Time Neural Network Based State Observer With Neural Network Based Control Formulation For A Class Of Systems With Unmatched Uncertainties, Jason Michael Stumfoll

Masters Theses

"An observer is a dynamic system that estimates the state variables of another system using noisy measurements, either to estimate unmeasurable states, or to improve the accuracy of the state measurements. The Modified State Observer (MSO) is a technique that uses a standard observer structure modified to include a neural network to estimate system states as well as system uncertainty. It has been used in orbit uncertainty estimation and atmospheric reentry uncertainty estimation problems to correctly estimate unmodeled system dynamics. A form of the MSO has been used to control a nonlinear electrohydraulic system with parameter uncertainty using a simplified …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar

Masters Theses

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior …

Hybrid Manufacturing Process Of SicF/Sic Composite Using Preceramic Polymer, Robert Raymond Meinders

Masters Theses

"Continuous fiber-reinforced silicon carbide (SiC_f/SiC) ceramic composites have been increasingly used due to their high temperature strength and graceful failure mechanisms. A disadvantage is the high cost and lengthy production processes that are required to develop these materials. Polymer infiltration and pyrolysis (PIP) is one of the most attractive fabrication processes for composites due to shape flexibility, mass production and relatively low cost; however, the quality of material obtained by this method has been considered insufficient due to the microstructure defects of the material obtained. This study investigated a hybrid of multiple polymer manufacturing processes to maximize quality …

Adjoint-Based Airfoil Shape Optimization In Transonic Flow, Joe-Ray Gramanzini

Masters Theses

"The primary focus of this work is efficient aerodynamic shape optimization in transonic flow. Adjoint-based optimization techniques are employed on airfoil sections and evaluated in terms of computational accuracy as well as efficiency. This study examines two test cases proposed by the AIAA Aerodynamic Design Optimization Discussion Group. The first is a two-dimensional, transonic, inviscid, non-lifting optimization of a Modified-NACA 0012 airfoil. The second is a two-dimensional, transonic, viscous optimization problem using a RAE 2822 airfoil. The FUN3D CFD code of NASA Langley Research Center is used as the ow solver for the gradient-based optimization cases. Two shape parameterization techniques …

Uncertainty Quantification Of Turbulence Model Closure Coefficients For Transonic Wall-Bounded Flows, John Anthony Schaefer

Masters Theses

"The goal of this work was to quantify the uncertainty and sensitivity of commonly used turbulence models in Reynolds-Averaged Navier-Stokes codes due to uncertainty in the values of closure coefficients for transonic, wall-bounded flows and to rank the contribution of each coefficient to uncertainty in various output flow quantities of interest. Specifically, uncertainty quantification of turbulence model closure coefficients was performed for transonic flow over an axisymmetric bump at zero degrees angle of attack and the RAE 2822 transonic airfoil at a lift coefficient of 0.744. Three turbulence models were considered: the Spalart-Allmaras Model, Wilcox (2006) k-ω Model, and the …