Euler's Three-Body Problem,
2021
University of Sao Paulo
Euler's Three-Body Problem, Sylvio R. Bistafa
Euleriana
In physics and astronomy, Euler's three-body problem is to solve for the motion of a body that is acted upon by the gravitational field of two other bodies. This problem is named after Leonhard Euler (1707-1783), who discussed it in memoirs published in the 1760s. In these publications, Euler found that the parameter that controls the relative distances among three collinear bodies is given by a quintic equation. Later on, in 1772, Lagrange dealt with the same problem, and demonstrated that for any three masses with circular orbits, there are two special constant-pattern solutions, one where the three bodies remain …
Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements,
2021
Georgia Institute of Technology
Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu
PRC-Affiliated Research
Citation: Hopping, E.P.; Huang, W.; Xu, K.G. Small Hall Effect Thruster with 3D Printed Discharge Channel: Design and Thrust Measurements. Aerospace 2021, 8, 227. https:// Abstract: This paper presents the design and performance of the UAH-78AM, a low-power small Hall effect thruster. The goal of this work is to assess the feasibility of using low-cost 3D printing to create functioning Hall thrusters, and study how 3D printing can expand the design space. The thruster features a 3D printed discharge channel with embedded propellant distributor. Multiple materials were tested including ABS, ULTEM, and glazed ceramic. Thrust measurements were obtained at the …
Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements,
2021
Georgia Institute of Technology
Small Hall Effect Thruster With 3d Printed Discharge Channel: Design And Thrust Measurements, Ethan P. Hopping, Wensheng Huang, Kunning G. Xu
PRC-Affiliated Research
Citation: Hopping, E.P.; Huang, W.; Xu, K.G. Small Hall Effect Thruster with 3D Printed Discharge Channel: Design and Thrust Measurements. Aerospace 2021, 8, 227. https:// Abstract: This paper presents the design and performance of the UAH-78AM, a low-power small Hall effect thruster. The goal of this work is to assess the feasibility of using low-cost 3D printing to create functioning Hall thrusters, and study how 3D printing can expand the design space. The thruster features a 3D printed discharge channel with embedded propellant distributor. Multiple materials were tested including ABS, ULTEM, and glazed ceramic. Thrust measurements were obtained at the …
Space Opens Its Doors To Unexpected Players, One Of Them Paraguay,
2021
Craig Newmark Graduate School of Journalism at CUNY
Space Opens Its Doors To Unexpected Players, One Of Them Paraguay, Macarena Carrizosa
Capstones
Paraguay successfully sent its first native satellite into orbit in 2021, proving how essential and accessible the industry has become, even for developing countries. This article looks at how knowledge and technology transfer programs combined with a lower cost of entry helped Paraguay reach its first major milestone in the space industry, having its own satellite.
Lightning Arc Channel Effects On Surface Damage Development On A Prseus Composite Panel: An Experimental Study,
2021
Texas A&M University
Lightning Arc Channel Effects On Surface Damage Development On A Prseus Composite Panel: An Experimental Study, Dounia Boushab, Pedram Gharghabi, Juhyeong Lee, Thomas E. Lacy Jr., Charles U. Pittman Jr., Michael S. Mazzola, Alexander Velicki
Mechanical and Aerospace Engineering Faculty Publications
Composite aircraft structures are vulnerable to lightning strike damage due to their relatively low electrical and thermal conductivities. A preceding work has investigated the lightning damage resistance of a carbon-epoxy Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panel. The damage includes intense local damage (i.e., matrix decomposition/sublimation, fiber rupture, delamination) accompanied by widespread surface damage (i.e., distributed fiber rupture and tow splitting) further from the lightning attachment point. This study focuses on investigating the cause of the widespread surface damage. Two possible driving mechanisms are explored: i) magnetically-induced currents and ii) lightning arc-root/channel expansion. …
Robust Nonlinear Tracking Control For Unmanned Aircraft In The Presence Of Wake Vortex,
2021
Embry-Riddle Aeronautical University
Robust Nonlinear Tracking Control For Unmanned Aircraft In The Presence Of Wake Vortex, Petr Kazarin, Vladimir Golubev, William Mackunis, Claudia Moreno
Publications
The flight trajectory of unmanned aerial vehicles (UAVs) can be significantly affected by external disturbances such as turbulence, upstream wake vortices, or wind gusts. These effects present challenges for UAV flight safety. Hence, addressing these challenges is of critical importance for the integration of unmanned aerial systems (UAS) into the National Airspace System (NAS), especially in terminal zones. This work presents a robust nonlinear control method that has been designed to achieve roll/yaw regulation in the presence of unmodeled external disturbances and system nonlinearities. The data from NASA-conducted airport experimental measurements as well as high-fidelity Large Eddy Simulations of the …
Radiation Effects On Space Solar Cells At Various Earth And Jupiter Orbital Altitudes,
2021
Purdue University
Radiation Effects On Space Solar Cells At Various Earth And Jupiter Orbital Altitudes, Naazneen Rana
Discovery Undergraduate Interdisciplinary Research Internship
Solar cells are used as the primary power source for earth-orbiting satellites and as a primary/secondary power source for various missions within the solar system. However, high energy particles from the sun, planetary magnetospheres, and the galaxy can affect the performance and life expectancy of the space solar cell and associated power systems. As the interests for interplanetary travel and the exploration of planets within our solar system increase, the need to understand a device’s performance within a particular planet’s environment is necessary. Therefore, this study will analyze the performance of space solar cells, particularly the SolAero IMM-α, at various …
Unmanned Aircraft Systems For Archaeology Using Photogrammetry And Lidar In Southwestern United States,
2021
Embry-Riddle Aeronautical University
Unmanned Aircraft Systems For Archaeology Using Photogrammetry And Lidar In Southwestern United States, Imai Bates-Domingo, Alexandra Gates, Patrick Hunter, Blake Neal, Kyle Snowden, Destin Webster
Study America
Researchers can use small unmanned aircraft systems (sUAS), also known as drones, to make observations of historical sites, help interpret locations, and make new discoveries that may not be visible to the naked eye. A student team from Embry-Riddle Aeronautical University gathered data for historical site documentation in New Mexico using the DJI Phantom 4 Pro V2, DJI Mavic Pro 2, DJI M210 and DJI M600, and senseFly eBee. Utilizing these drones, student analysts were able to take the data gathered and create georectified orthomosaic images and 3D virtual objects. At Tularosa Canyon, at a site known as the Creekside …
Stress Analysis Of Functionally Graded Materials,
2021
University of Texas at Arlington
Stress Analysis Of Functionally Graded Materials, Nilabh Krishna
Mechanical and Aerospace Engineering Dissertations - Archive
A functionally graded material (FGM) is an inhomogeneous material whose material properties vary continuously. Since FGM’s material properties are continuous at the interface of the two materials, unlike conventional composites whose material properties are discontinuous at the interface, it is best suited to prevent catastrophically failure, stress concentration, and residual stresses. Literature reviews revealed that most of the research on FGMs was a 2-D analysis, especially on FGM plates and beams. This research focuses on 3-D stress analysis for an elastic medium that contains a spherical inclusion made of an FGM embedded in a matrix phase. To the best of …
Effect Of Thermal Conductivity, Reynolds Number, Aspect Ratio And Packing Arrangement On Radial Heat Transfer In Packed Beds,
2021
University of Texas at Arlington
Effect Of Thermal Conductivity, Reynolds Number, Aspect Ratio And Packing Arrangement On Radial Heat Transfer In Packed Beds, Nishith Gorla
Mechanical and Aerospace Engineering Dissertations - Archive
The key motivation for this research is to study heat transfer developments in packed beds. The radial heat transfer enhancement of a packed bed in the laminar flow region is one of the major areas of ongoing research in mechanical, aerospace and chemical industries, especially the response of a packed bed during conjugate heat transfer with the fluid-solid interaction. This computational study focuses on the impact of packing size, thermal conductivity, and arrangement on the radial heat transfer performance as a function of Reynolds number. A simple annular tube packed with circles (2D) and spheres (3D) is utilized for this …
Modeling The Effect Of In Situ Nozzle-Integrated Compression Rolling On The Mechanical And Fracture Behavior Of Fused Filament Fabrication (Fff) 3d Printed Parts,
2021
University of Texas at Arlington
Modeling The Effect Of In Situ Nozzle-Integrated Compression Rolling On The Mechanical And Fracture Behavior Of Fused Filament Fabrication (Fff) 3d Printed Parts, Momen Mohammad Qasaimeh
Mechanical and Aerospace Engineering Dissertations - Archive
Fused filament fabrication (FFF) is one of the most common additive manufacturing/3D printing techniques where continuously extruded semi-molten filaments are deposited in a layer-by-layer manner. The quality of the manufactured part depends on some major factors such as filament-filament contact and adhesion as well as the void fraction. Filament to filament adhesion affects the part strength under transverse load. In our earlier work, we studied the effect of in situ ball rolling on the thermal and mechanical properties of the printed parts. It was found that when printing/rolling parameters are correctly tuned and in situ compression rolling is appropriately applied …
Set-Theoretic Frameworks For Online Optimization, Estimation, And Control,
2021
University of Texas at Arlington
Set-Theoretic Frameworks For Online Optimization, Estimation, And Control, Dignata Bhattacharjee
Mechanical and Aerospace Engineering Dissertations - Archive
This research is primarily focused on developing online frameworks, which are suited to real-time implementation, for performance optimization, estimation, and control of dynamical systems using set-theoretic concepts and/or having set-theoretic interpretations. First, two perturbation-based extremum seeking control schemes, based on the classical setup and equipped with novel adaptation laws for the perturbation signal amplitudes, are proposed for general single input single output nonlinear systems. The proposed schemes are able to extremize steady-state system output in a practical asymptotic sense, i.e., the system is driven to an arbitrarily small set centered at the true steady-state optimal operating point. The next development …
Uncertainty Propagation, Control, And Estimation Of Stochastic Dynamic Systems Using Generalized Polynomial Chaos Expansion,
2021
University of Texas at Arlington
Uncertainty Propagation, Control, And Estimation Of Stochastic Dynamic Systems Using Generalized Polynomial Chaos Expansion, Rajnish Bhusal
Mechanical and Aerospace Engineering Dissertations - Archive
In recent years, uncertainty propagation has emerged as an important research area in the field of dynamical systems. The growing interest in this area arises out of the need to develop computationally efficient approaches to predict the evolution of a system subject to uncertainties. To this end, this dissertation is focused on developing computational frameworks for uncertainty propagation, control, and state estimation of stochastic dynamical systems using the generalized polynomial chaos (gPC) expansion technique. In the first part of this dissertation, the construction of gPC expansion is presented in general. The novelty of this dissertation lies in developing a mixed …
Computational Investigation Of Energy Dissipation Through Progressive Failure In Tailored Composite Structures Via Explicit Finite Element Analysis,
2021
University of Texas at Arlington
Computational Investigation Of Energy Dissipation Through Progressive Failure In Tailored Composite Structures Via Explicit Finite Element Analysis, Anirudh Srinivas
Mechanical and Aerospace Engineering Dissertations - Archive
In this study, energy dissipation in structures implementing a previously developed, analytically modeled, and experimentally validated composite tailoring concept is investigated using an explicit finite element approach. The tailored composite structures consist in a series connection of parallel alternate load paths of tailored length and thickness. The advantage of the tailored structure when compared to an untailored conventional structure is that when subjected to a tensile load, the response of the tailored composite structure is characterized by progressive failure of the load paths resulting in increased energy dissipation. The tailored composite structure is modeled for IM7-8552 composite material using a …
Laminar Swept And Cross Shockwave/Boundary-Layer Interactions,
2021
University of Texas at Arlington
Laminar Swept And Cross Shockwave/Boundary-Layer Interactions, Jiss Jacob Sebastian
Mechanical and Aerospace Engineering Dissertations - Archive
Shockwave/boundary-layer interactions are considered one of the most complex problems in high-speed gas dynamics, and numerous studies have been carried out for more than eighty years to understand the fundamental physics. A numerical study was performed using fin-plate configurations to study the three-dimensional swept and cross shockwave/ laminar boundary-layer interactions. All the interactions studied were strong enough for the boundary layer to separate. In the first part, swept shock interactions between a laminar boundary layer and the shockwave induced by a sharp fin mounted perpendicularly on a flat plate were studied. Different flow conditions were investigated at freestream Mach numbers …
Design, Operation And Maintenance Of Direct And Indirect Evaporative Cooling Systems In Data Center Thermal Management,
2021
University of Texas at Arlington
Design, Operation And Maintenance Of Direct And Indirect Evaporative Cooling Systems In Data Center Thermal Management, Ashwin Siddarth
Mechanical and Aerospace Engineering Dissertations - Archive
Evaporative cooling is an alternative data center cooling solution that presents significant energy cost savings in acquisition and operation when compared to conventional air conditioning and mechanical refrigeration systems. This research focuses on developing a deeper understanding in implementing, operating and maintaining evaporative cooling systems integrated with air-side economization to realize the energy savings potential in data center cooling. The goal of the research is to develop a comprehensive guide to assess and contrast different approaches of evaporative cooling being used in data center cooling and provide guidance in improving water and energy efficiency. An air handling unit (AHU) serves …
Design Of Streamline-Traced Inlets And Their Integration With Rotating Detonation Engines,
2021
University of Texas at Arlington
Design Of Streamline-Traced Inlets And Their Integration With Rotating Detonation Engines, Malcolm Lee Branch
Mechanical and Aerospace Engineering Theses - Archive
This thesis has two parts: 1) design of the streamline-traced inlets (STIs); and 2) integration of STIs with rotating detonation engines (RDEs). The STI design starts with a two-dimensional, isentropic compression flowfield as the parent flowfield. The method of characteristics was used to generate the flowfield throughout the entire STI. For a given flight altitude 18 km, freestream Mach number M?=3.0, and inlet exit-plane Mach number M?=1.2, a parametric sweep of the initial deflection angle ?1=4.0--11.0 deg and the Mach number at the entrance of the internal compression system M3=1.3--1.7 was performed to determine the STI performance sensitivity as a …
Haptic Interface Optimization For Virtual Anastomosis Surgery Training,
2021
University of Texas at Arlington
Haptic Interface Optimization For Virtual Anastomosis Surgery Training, Kangji Huang
Mechanical and Aerospace Engineering Theses - Archive
Virtual anastomosis surgery study allows surgeons to perform or practice suturing in virtual reality using a commercial haptic device. The haptic device can generate force feedback so that the user can feel the real touch sensation of the object in virtual reality. The virtual anastomosis surgery study has two requirements which are that the haptic device must be fixed on the operating table and haptic device location must be suitable for different surgeons. The goal is to use a commercially available haptic device for this purpose, rather than design a new device for each possible surgery that must be performed. …
Design And Cfd Analysis Of Bimetallic Based Passive Dynamic Cold Plate For High Power Direct-To-Chip Liquid Cooling,
2021
University of Texas at Arlington
Design And Cfd Analysis Of Bimetallic Based Passive Dynamic Cold Plate For High Power Direct-To-Chip Liquid Cooling, Apurv Pravin Deshmukh
Mechanical and Aerospace Engineering Theses - Archive
Rising demand for high-performance chips results in the need for advanced and efficient cooling technologies like direct to chip liquid cooling. Cold plates based utilizing direct liquid cooling is one of the most efficient and the most investigated cooling technology since the 1980s. Major data services and cloud providers like IBM, Microsoft, and Google had already started a shift towards liquid-cooled data centers for their high computational servers. At the chip level nowadays, the processors are divided into several cores and each of these cores continuously works at varying computational demands. This creates a non-uniform heat distribution across the processor, …
Simulation Of A Soft Body Non-Grasp Manipulator Using A Spring-Mass-Damper Cloth Model,
2021
University of Texas at Arlington
Simulation Of A Soft Body Non-Grasp Manipulator Using A Spring-Mass-Damper Cloth Model, Cristian Almendariz
Mechanical and Aerospace Engineering Theses - Archive
Simulation and modeling are well known and important tools in the field of robotics, being used to validate design and in the development of robotic control systems. Traditionally, robotic systems have been primarily rigid body systems and used in well controlled environments where interactions are highly predictable, and exceptions are minimized. With the ever-increasing adoption of robotics in the medical field, typical robotic environments are becoming highly unpredictable and requiring the modeling and simulation of not only rigid body systems but soft systems and interactions between the two. This work addresses model improvement of a “soft and hard” robotic system …
