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Articles 31 - 56 of 56

Full-Text Articles in Systems Engineering and Multidisciplinary Design Optimization

Dual Graphene Patch Antenna For Ka Band Satellite Applications, Mohammed Amin Rabah, Mohammed Bekhti Jan 2019

Dual Graphene Patch Antenna For Ka Band Satellite Applications, Mohammed Amin Rabah, Mohammed Bekhti

International Journal of Aviation, Aeronautics, and Aerospace

Currently; grapheme offers a new opportunity to use in space technology and this is due to its amazing properties like conductivity, strength, flexibility and transparency which allows us to exploit new generation of ultra-fast nanoscale components; Since future wireless communication techniques are geared towards the use of the high frequency spectrum and many recent research prove this trend. This letter presents a proposal for design of a dual graphene-based antenna to use in new communication techniques in Ka band, where the proposed antenna can work for uplink and dowlink frequencies at same time since it has return loss less then …


Improving The Delivered Specific Impulse Of Composite Rocket Propellant Through Alteration Of Chemical Composition: Methodology And Parameters For Characterization Of Propellant And Validation Of Simulation Software Common To The Amateur Rocketry Community, Isaac O'Brien, Austin Ryan Jan 2019

Improving The Delivered Specific Impulse Of Composite Rocket Propellant Through Alteration Of Chemical Composition: Methodology And Parameters For Characterization Of Propellant And Validation Of Simulation Software Common To The Amateur Rocketry Community, Isaac O'Brien, Austin Ryan

Williams Honors College, Honors Research Projects

In this study, two solid composite rocket propellants were designed utilizing ProPEP, a rocket propellant formulation software common in the amateur and hobby rocketry communities. The two propellants were designed to optimize specific impulse relative to a literature propellant designed by 1020 Research Labs. The literature propellant was also tested in order to validate the design of experiment as well as the mixing and testing procedures. All three propellants, which includes the literature propellant RCS-P, and the two novel propellants AKR-P1 and AKR-P2 were characterized with static tests. The results of the static tests provide data on propellant performance and …


Landing-Gear Impact Response: A Non-Linear Finite Element Approach, Tuan H. Tran Jan 2019

Landing-Gear Impact Response: A Non-Linear Finite Element Approach, Tuan H. Tran

UNF Graduate Theses and Dissertations

The primary objective of this research is to formulate a methodology of assessing the maximum impact loading condition that will incur onto an aircraft’s landing gear system via Finite Element Analysis (FEA) and appropriately determining its corresponding structural and impact responses to minimize potential design failures during hard landing (abnormal impact) and shock absorption testing. Both static and dynamic loading condition were closely analyzed, compared, and derived through the Federal Aviation Administration’s (FAA) airworthiness regulations and empirical testing data.

In this research, a nonlinear transient dynamic analysis is developed and established via NASTRAN advanced nonlinear finite element model (FEM) to …


Techedsat 7 And 8-Nasa Missions For Earth Observation, Andrew Pham Sep 2018

Techedsat 7 And 8-Nasa Missions For Earth Observation, Andrew Pham

STAR Program Research Presentations

Big results can come from small satellites, and Technology Educational Satellite 8 or TES-8 is the latest small satellite in the TechEdSat series from NASA Ames Research Center. TechEdSat is a collaborative program, in which advanced university students have a chance to work directly with researchers on NASA Space Projects. Thanks to the assistance of students from several universities around the country every year, TechEdSat has helped NASA develop Nano-satellite technologies and evaluate new ideas for future spacecraft. TES-8 is the eighth satellite of the continuing TechEdSat series. On December 01, 2018 TES-8 followed a Commercial Resupply Service mission to …


Cubesat Adcs Validation And Testing Apparatus, Jacob Stevens Dec 2016

Cubesat Adcs Validation And Testing Apparatus, Jacob Stevens

Honors Theses

The WALI team at Western Michigan University requested a test environment to validate their CubeSat’s de-tumbling control system and hardware. The test environment required a Helmholtz cage and spherical air bearing. The Helmholtz cage provides an adjustable magnetic field to simulate low earth orbit; the spherical air bearing simulates the friction free environment the CubeSat will experience in space. In conjunction, the two components create an adjustable system that simulates a satellite in low earth orbit.


From Xst To F-117a, Alan Brown Sep 2016

From Xst To F-117a, Alan Brown

ERAU Prescott Aviation History Program

Learn the remarkable story of stealth technology from the man often referred to as “Mr. Stealth.” From 1975-1989 Alan Brown was a member of Lockheed “Skunk Works”, becoming program manager & chief engineer for the F-117A Stealth Fighter from initial concept until the first production aircraft was built, 1978 to 1982. Hear the inside story of the many challenges faced by the stealth program and how they were solved.


Techniques For Payload Stabilization For Improved Photography During Stratospheric Balloon Flights, James Flaten, Christopher Gosch, Joseph (Benjamin) Habeck Jun 2015

Techniques For Payload Stabilization For Improved Photography During Stratospheric Balloon Flights, James Flaten, Christopher Gosch, Joseph (Benjamin) Habeck

2017 Academic High Altitude Conference

Payload-box rotation and swing are perennial challenges to achieving high-quality photography (typically videography) during weather-balloon flights to “near-space” (AKA the stratosphere). Continuous camera motion can lead to blurred still photos, nearly-impossible-to-watch video footage, and precludes time-exposure photography required for most astronomical imaging even though altitudes are reached where the daytime sky appears black. Apparently-random payload rotation, persisting even at altitude, can often exceed servo rotation rates and frustrate attempts to do active camera pointing. Here we discuss mostly-passive payload stabilization strategies we, and our collaborators, have used to mitigate and dampen both swing and rotation of suspended payloads on high-altitude …


Automatic Building Change Detection In Wide Area Surveillance, Paheding Sidike, Almabrok Essa, Fatema Albalooshi, Vijayan K. Asari, Varun Santhaseelan Jun 2015

Automatic Building Change Detection In Wide Area Surveillance, Paheding Sidike, Almabrok Essa, Fatema Albalooshi, Vijayan K. Asari, Varun Santhaseelan

Electrical and Computer Engineering Faculty Publications

We present an automated mechanism that can detect and characterize the building changes by analyzing airborne or satellite imagery.

The proposed framework can be categorized into three stages: building detection, boundary extraction and change identification. To detect the buildings, we utilize local phase and local amplitude from monogenic signal to extract building features for addressing issues of varying illumination. Then a support vector machine with Radial basis kernel is used for classification. In the boundary extraction stage, a level-set function with self-organizing map based segmentation method is used to find the building boundary and compute physical area of the building …


Design Of The Structural And Propulsion Systems For The 2015 University Of Akron Rocket Team, Kyle W. Dehoff, Nicholas J. Hrusch Jan 2015

Design Of The Structural And Propulsion Systems For The 2015 University Of Akron Rocket Team, Kyle W. Dehoff, Nicholas J. Hrusch

Williams Honors College, Honors Research Projects

No abstract provided.


Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D. Nov 2014

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …


Foss Big Data Storage Solution, Gary L. Jaffe Aug 2014

Foss Big Data Storage Solution, Gary L. Jaffe

STAR Program Research Presentations

Utilizing the AERO Institute as an IT test bed or “sandbox”, a small-agile development team will design, build, and test a data management storage system to support post processing of archived and in-flight data collected with the Piccolo flight control system and Compact Fiber Optic Sensing System (C-FOSS). Both systems are integrated on the APV3 aircraft, a small remote-operated vehicle. Due to the amount of data collected from C-FOSS, a system will be designed to sort and organize large data sets. An open-source database will be explored as a viable solution to manage large data loads and provide multi-cluster system …


Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr. Jun 2013

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …


Numerical Modeling And Characterization Of Vertically Aligned Carbon Nanotube Arrays, Johnson Joseph Jan 2013

Numerical Modeling And Characterization Of Vertically Aligned Carbon Nanotube Arrays, Johnson Joseph

Theses and Dissertations--Mechanical and Aerospace Engineering

Since their discoveries, carbon nanotubes have been widely studied, but mostly in the forms of 1D individual carbon nanotube (CNT). From practical application point of view, it is highly desirable to produce carbon nanotubes in large scales. This has resulted in a new class of carbon nanotube material, called the vertically aligned carbon nanotube arrays (VA-CNTs). To date, our ability to design and model this complex material is still limited. The classical molecular mechanics methods used to model individual CNTs are not applicable to the modeling of VA-CNT structures due to the significant computational efforts required. This research is to …


Two-Stage, High-Altitude Rocket With Internal Skeleton Design Entered In Advance Category Of 7th Esra Irec, Samuel S. Bowman, Kevin J. Byrne, Allen Capatina, Aliki S. Loper-Leddy, Joshua A. Van Schoyck Aug 2012

Two-Stage, High-Altitude Rocket With Internal Skeleton Design Entered In Advance Category Of 7th Esra Irec, Samuel S. Bowman, Kevin J. Byrne, Allen Capatina, Aliki S. Loper-Leddy, Joshua A. Van Schoyck

Aerospace Engineering

A high-altitude, two-stage rocket was designed, built, and entered in the advanced category of the 7th Annual Experimental Sounding Rocket Association (ESRA) Intercollegiate Rocketry Engineering Competition (IREC). The rocket, called AJAKS, featured an internal skeleton made of carbon fiber rods, and a combination of plywood, carbon, and aluminum bulkheads. Loads were driven through the internal structure, with an outer skin tube providing an aerodynamic surface. A unique separation device was developed to ensure proper stage separation. The competition required the rocket to carry a 10-lb payload, which was chosen by the team to consist of an IMU and data …


Response Surface Optimization Of Electron Beam Freeform Fabrication Depositions Using Design Of Experiments, Patricia A. Quigley Jul 2012

Response Surface Optimization Of Electron Beam Freeform Fabrication Depositions Using Design Of Experiments, Patricia A. Quigley

Engineering Management & Systems Engineering Theses & Dissertations

The Electron Beam Freeform Fabrication (EBF3 ) System is a material depositing, layer additive technique that produces three dimensional (3D) parts out of a wide range of metals in high vacuum, using an electron beam and wire feedstock. Screening deposition trials on a titanium alloy, Ti-6Al-4V, at the National Aeronautics Space Administration (NASA) revealed selective vaporization of the aluminum content of linear prototypes when subjected to chemical analysis. In this study, the aluminum content, bead height and bead width output responses were analyzed from a systematic study of the effects that the interactions of the EBF3 processing parameters …


Analysis And Testing Of Heat Transfer Through Honeycomb Panels, Daniel D. Nguyen May 2012

Analysis And Testing Of Heat Transfer Through Honeycomb Panels, Daniel D. Nguyen

Aerospace Engineering

This project attempts to simulate accurately the thermal conductivity of honeycomb panels in the normal direction. Due to the large empty space of the honeycomb core, the thermal radiation mode of heat transfer was modeled along with conduction. Using Newton’s Method to solve for a steady state model of heat moving through the honeycomb panel, the theoretical effective thermal conduction of the honeycomb panel was found, ranging from 1.03 to 1.07 Q/m/K for a heat input of 2.5 W to 11.8 W. An experimental model was designed to test the theoretical results, using a cold plate and a heat plate …


Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar Jun 2011

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …


Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey Jun 2009

Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey

Master's Theses

ABSTRACT

Multidisciplinary Design Optimization of an Extreme Aspect Ratio HALE UAV

Bryan J. Morrisey

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. Presently, several development efforts are underway in this field, including a project sponsored by DARPA that aims at producing an aircraft that can sustain flight for multiple years and …


Assessment Of Preliminary Design Approaches For Metallic Stiffened Cylindrical Shell Instability Problems, Vicki Owen Britt Apr 2007

Assessment Of Preliminary Design Approaches For Metallic Stiffened Cylindrical Shell Instability Problems, Vicki Owen Britt

Mechanical & Aerospace Engineering Theses & Dissertations

A preliminary design tool for metallic stiffened fuselage cylindrical panels subjected to longitudinal compression has been developed and validated by comparison to test results. Several methodologies for stiffened panel buckling and failure predictions were examined and evaluated. An appropriate level of analysis fidelity was determined for different failure modes and design details. Results from panel tests conducted to verify analytical methods used to design the Gulfstream V aircraft were presented. The panels were representative of four general skin/stringer configurations on the aircraft. Finite Element analyses and standard analytical methods were used to predict panel failure loads. The accuracy of the …


Optimal Aeroelastic Vehicle Sensor Placement For Root Migration Flight Control Applications, Abdul Ghafoor Al-Shenhabi Jul 2001

Optimal Aeroelastic Vehicle Sensor Placement For Root Migration Flight Control Applications, Abdul Ghafoor Al-Shenhabi

Mechanical & Aerospace Engineering Theses & Dissertations

An important step in control design for elastic systems is the determination of the number and location of control system components, namely sensors. The number and placement of sensors can be critical to the robust functioning of active control systems, especially when the system of interest is a large high-speed aeroelastic vehicle. The position of the sensors affects not only system stability, but also the performance of the closed-loop system. In this dissertation, a new approach for sensor placement in the integrated rigid and vibrational control of flexible aircraft structures is developed. Traditional rigid-body augmentation objectives are addressed indirectly through …


An Integrated Risk Analysis Methodology In A Multidisciplinary Design Environment, Katrina R. Hampton Jan 2001

An Integrated Risk Analysis Methodology In A Multidisciplinary Design Environment, Katrina R. Hampton

Engineering Management & Systems Engineering Theses & Dissertations

Design of complex, one-of-a-kind systems, such as space transportation systems, is characterized by high uncertainty and, consequently, high risk. It is necessary to account for these uncertainties in the design process to produce systems that are more reliable. Systems designed by including uncertainties and managing them, as well, are more robust and less prone to poor operations as a result of parameter variability.

The quantification, analysis and mitigation of uncertainties are challenging tasks as many systems lack historical data. In such an environment, risk or uncertainty quantification becomes subjective because input data is based on professional judgment. Additionally, there are …


Studies Related To The Design Of A Magnetic Suspension And Balance System For An Ultra-High Reynolds Number Flow Facility, Oscar Magno Michael Gomeiz Jan 1999

Studies Related To The Design Of A Magnetic Suspension And Balance System For An Ultra-High Reynolds Number Flow Facility, Oscar Magno Michael Gomeiz

Mechanical & Aerospace Engineering Theses & Dissertations

The basic design principles for a magnetic suspension and balance system applied to the test section of an ultra-high Reynolds number facility are defined. The design of the cross-sectional area to be used in the test section is analyzed. The parameters of the permanent magnet to be used in the model inside the test section are investigated. The testing of magnetic fields at the center of a test pipe and validation of data by computer finite element analysis is described with the purpose of finding common results. The performance of the magnet configuration is evaluated with relation to the magnetic …


Input Design For Systems Under Identification Using Indirect And Direct Methods, Marco P. Schoen Mar 1997

Input Design For Systems Under Identification Using Indirect And Direct Methods, Marco P. Schoen

Mechanical & Aerospace Engineering Theses & Dissertations

The motivation for system identification can be manifold. In this work, the provocation to identify unknown system characteristics is derived from the control engineering point of view. That is, one intends to design a control strategy based on the identified system properties. The used system identification methods are the Open-Loop Kalman filter System Identification method (OKID) and the Closed-Loop System Identification method (CLID). It is shown that the quantitative largest error of the system identification is given by its model representation, that is the attempt to describe a system with model parameters which poses a linear relationship with the input/output …


Theoretical Results Supporting The Use Of Passive Damping As Augmentation To The Active Control Of Flexible Structures, Joseph Vincent Harrell Jan 1993

Theoretical Results Supporting The Use Of Passive Damping As Augmentation To The Active Control Of Flexible Structures, Joseph Vincent Harrell

Mechanical & Aerospace Engineering Theses & Dissertations

One challenge of modern control technology is how to control a flexible structure with accuracy, speed, and economy of effort. Controlling a structure with many degrees of freedom by purely active means implies the implementation of inordinate sensors and actuators and creates the need for numerous calculations that must be done instantly. Experiments have shown that practical structures under active control alone can suffer instabilities due to modal vibrations beyond the bandwidth of the active controller. Furthermore, if there is a high degree of model uncertainty, instabilities can be produced by inputs of modal vibrations not occurring in the system …


Maximum Likelihood Estimation For Distributed Parameter Models Of Large Beam-Like Structures, Ji Yao Shen Apr 1991

Maximum Likelihood Estimation For Distributed Parameter Models Of Large Beam-Like Structures, Ji Yao Shen

Mechanical & Aerospace Engineering Theses & Dissertations

Proposed large space structures have many characteristics that give an advantage to modeling their structural dynamics by a set of partial differential equations (PDE's). By far, the most effort put forth in studying system identification and control to date has been based on finite element models. Despite its acceptability, such lumped parameter models have inevitable deficiencies primarily because of their complexity. Both approaches are complementary and each should be used where it is most effective. But the fact is that the distributed parameter approach has not been developed to the level of maturity as for the lumped parameter approach.

Motivated …


High Heat Flux Cooling For Spacecraft Electronics, Louis C. Chow, John E. Leland Jan 1991

High Heat Flux Cooling For Spacecraft Electronics, Louis C. Chow, John E. Leland

Office for Research Publications and Presentations

An experimental investigation of flow boiling in a curved channel has been performed to ascertain its value in electronics cooling applications. Results have been obtained for flow velocities of 1 to 5 m/s and subcooling of 0.5 to 40 K. These results were compared to those of straight channel under identical velocity and subcooling conditions. The critical heat flux of the curved channel was found to be greater than that of the straight channel. In some cases the increase was found to be marginal, however. An unexplained temperature shift in the nucleate boiling regime was experienced during some experiments. Because …