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Articles 571 - 600 of 854

Full-Text Articles in Systems Engineering and Multidisciplinary Design Optimization

Applications Of Polynomial Chaos-Based Cokriging To Aerodynamic Design Optimization Benchmark Problems, Jethro Nagawkar, Leifur Leifsson, Xiaosong Du Jan 2020

Applications Of Polynomial Chaos-Based Cokriging To Aerodynamic Design Optimization Benchmark Problems, Jethro Nagawkar, Leifur Leifsson, Xiaosong Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this work, the polynomial chaos-based Cokriging (PC-Cokriging) is applied to a benchmark aerodynamic design optimization problem. The aim is to perform fast design optimization using this multifidelity metamodel. Multifidelity metamodels use information at multiple levels of fidelity to make accurate and fast predictions. Higher amount of lower fidelity data can provide important information on the trends to a limited amount of high-fidelity (HF) data. The PC-Cokriging metamodel is a multivariate version of the polynomial chaos-based Kriging (PC-Kriging) metamodel and its construction is similar to Cokriging. It combines the advantages of the interpolation-based Kriging metamodel and the regression-based polynomial chaos …


Satellite Constellation Deployment And Management, Joseph Ryan Kopacz Jan 2020

Satellite Constellation Deployment And Management, Joseph Ryan Kopacz

Electronic Theses and Dissertations

This paper will review results and discuss a new method to address the deployment and management of a satellite constellation. The first two chapters will explorer the use of small satellites, and some of the advances in technology that have enabled small spacecraft to maintain modern performance requirements in incredibly small packages.

The third chapter will address the multiple-objective optimization problem for a global persistent coverage constellation of communications spacecraft in Low Earth Orbit. A genetic algorithm was implemented in MATLAB to explore the design space – 288 trillion possibilities – utilizing the Satellite Tool Kit (STK) software developers kit. …


Identify Aerodynamic Derivatives Of The Airplane Attitude Channel Using A Spiking Neural Network, Nguyen Quang Vinh, Nguyen Duc Thanh, Hoang Minh Dac, Truong Dang Khoa Jan 2020

Identify Aerodynamic Derivatives Of The Airplane Attitude Channel Using A Spiking Neural Network, Nguyen Quang Vinh, Nguyen Duc Thanh, Hoang Minh Dac, Truong Dang Khoa

International Journal of Aviation, Aeronautics, and Aerospace

The paper proposes a method for identifying aerodynamic coefficient derivatives of aircraft attitude channel using spiking neural network (SNN) and Gauss-Newton algorithm based on data obtained from actual flights. Using SNN combination with Gauss-Newton iterative calculation algorithm allows the identification of aerodynamic coefficient derivatives in a nonlinear model for aerodynamic parameters with higher accuracy and faster calculation time. The paper proposes an algorithm to train the SNN multi-layer network by Normalized Spiking Error Back Propagation (NSEBP), in which, in the forward propagation period, the time of output spikes is calculating by solving quadratic equations instead of detection by traditional methods. …


Low Thrust And Low Power Propulsion Systems Options For Small Satellites, Redha Amri Jan 2020

Low Thrust And Low Power Propulsion Systems Options For Small Satellites, Redha Amri

International Journal of Aviation, Aeronautics, and Aerospace

The present work focuses on the study of low thrust propulsion systems. Cold gas, thermal and monopropellant systems with a blow down depressurisation mode have been taken in consideration in this study. Most of propellants that can be used for small satellite propulsion systems were selected here in order to give the propulsion engineer many propellant options with a good idea about the performance of each propellant, and this is important to make a good trade-off during the system design. For cold gas and thermal propulsion, the propellants taken into account in this study are: Oxygen (O2), Nitrogen (N2), Hydrogen …


Performance Enhancement And Characterization Of An Electromagnetic Railgun, Paul M. Gilles Dec 2019

Performance Enhancement And Characterization Of An Electromagnetic Railgun, Paul M. Gilles

Master's Theses

Collision with orbital debris poses a serious threat to spacecraft and astronauts. Hypervelocity impacts resulting from collisions mean that objects with a mass less than 1g can cause mission-ending damage to spacecraft. A means of shielding spacecraft against collisions is necessary. A means of testing candidate shielding methods for their efficacy in mitigating hypervelocity impacts is therefore also necessary. Cal Poly’s Electromagnetic Railgun was designed with the goal of creating a laboratory system capable of simulating hypervelocity (≥ 3 km/s) impacts. Due to several factors, the system was not previously capable of high-velocity (≥ 1 km/s) tests. A deficient projectile …


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr. Oct 2019

Entrapped Oxide Formation In The Friction Stir Weld (Fsw) Process, Judy Schneider, Poshou Chen, Arthur C. Nunes Jr.

PRC-Affiliated Research

The ultimate design values for a friction stir weld (FSW) are not based on the average strength, but the lowest strength or outlier. Thus, the robustness of the process could be ultimately increased by understanding and minimizing the sources of data scatter within the mechanical properties of a FSW panel. Internal voids are known to result in reduced strength, but are detectable using non-destructive evaluation (NDE). Other metallurgical discontinuities, such as internal oxides, are difficult to detect using NDE and are often blamed for random variations in the mechanical properties of FSWs. Current efforts to minimize internal oxides within a …


Design Of The 21-Meter Network Monitor And Control System For Deep Space Network Cross Support, Sarah E. Wilczewski Sep 2019

Design Of The 21-Meter Network Monitor And Control System For Deep Space Network Cross Support, Sarah E. Wilczewski

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by Sarah E. Wilczewski on September 26, 2019.


Experimental And Numerical Analysis Of Quasi-Static Deformation Mechanisms Of Additively Manufactured Lattice Structures, Behzad Bahrami Babamiri Sep 2019

Experimental And Numerical Analysis Of Quasi-Static Deformation Mechanisms Of Additively Manufactured Lattice Structures, Behzad Bahrami Babamiri

Von Braun Symposium Student Posters

No abstract provided.


Evaluation Of Varying Surface Finishes On Thin-Walled Blown Powdered Deposition Inconel 625, Noah Naden, Giancarlo Puerto, Judy Schneider Sep 2019

Evaluation Of Varying Surface Finishes On Thin-Walled Blown Powdered Deposition Inconel 625, Noah Naden, Giancarlo Puerto, Judy Schneider

Von Braun Symposium Student Posters

No abstract provided.


Aircraft Hydraulic Systems - Fundamentals, Nihad E. Daidzic Sep 2019

Aircraft Hydraulic Systems - Fundamentals, Nihad E. Daidzic

Aviation Department Publications

Aircraft hydraulic systems are essential non-propulsive power systems. Hydraulic power systems are used to power major functional aircraft systems, such as flight controls (primary and secondary), friction braking, nose gear steering, thrust-reversers, operating heavy cargo doors, etc.


Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson Sep 2019

Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson

Master's Theses

The CubeSat Astronomy Network is a proposed system of multiple CubeSat spacecraft capable of performing follow-up observations of astronomical targets of interest. The system is intended to serve as a space-borne platform that can complement existing systems utilized for astronomical research by undergraduate and high school students. Much research and development work has been performed to develop model-based system engineering methodologies and products for CubeSat missions, including the Horizon Simulation Framework. The Horizon Simulation Framework enables the development of system models using the Extended Markup Language (XML), and its simulation program can generate system simulations over model-specified timespans. System requirements …


A Homegrown Dsmc-Pic Model For Electric Propulsion, Dominic Charles Lunde Jun 2019

A Homegrown Dsmc-Pic Model For Electric Propulsion, Dominic Charles Lunde

Master's Theses

Powering spacecraft with electric propulsion is becoming more common, especially in CubeSat-class satellites. On account of the risk of spacecraft interactions, it is important to have robust analysis and modeling tools of electric propulsion engines, particularly of the plasma plume. The Navier-Stokes equations used in classic continuum computational fluid dynamics do not apply to the rarefied plasma, and therefore another method must be used to model the flow. A good solution is to use the DSMC method, which uses a combination of particle modeling and statistical methods for modeling the simulated molecules. A DSMC simulation known as SINATRA has been …


Comparison Of Induced And Parasitic Drag On Wings With Minimum Induced Drag, Sarah A. Abdel-Motaleb May 2019

Comparison Of Induced And Parasitic Drag On Wings With Minimum Induced Drag, Sarah A. Abdel-Motaleb

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Minimizing the induced drag for steady level flight is a variational problem that requires solving for the optimum lift distribution given a set of design constraints. From lifting-line theory, minimizing the induced drag is, in part, achieved by varying the Fourier coefficients used to describe the section lift. The elliptic lift distribution minimizes the induced drag for a wing with fixed weight and wingspan by setting all but the first coefficient to zero. If wingspan is allowed to vary, a negative third Fourier coefficient is utilized to reach an optimum lift distribution that further reduces the induced drag for stress-limited …


Fast Yield Estimation Of Multi-Band Patch Antennas By Pc-Kriging, Xiaosong Du, Leifur Leifsson, Slawomir Koziel May 2019

Fast Yield Estimation Of Multi-Band Patch Antennas By Pc-Kriging, Xiaosong Du, Leifur Leifsson, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The PC-Kriging metamodeling method is proposed for yield estimation of multi-band patch antennas. PC-Kriging is a combination of polynomial chaos expansion (PCE) and Kriging metamodeling, where PCE is used as a trend function for the Kriging interpolation metamodel. The method is demonstrated on the Ishigami analytical function and a dual-band patch antenna. The PC-Kriging is shown to reach the prescribed accuracy limit with significantly fewer training points than both PCE and Kriging. This translates into considerable computational savings of yield estimation over alternative metamodel-based procedures and direct EM-driven Monte Carlo simulation. The saving are obtained without compromising evaluation reliability.


Extreme Altitude Search And Rescue Helicopter, Matthew J. De Sieno, Anthony Chavarria, David Stuver, Zach Boss Apr 2019

Extreme Altitude Search And Rescue Helicopter, Matthew J. De Sieno, Anthony Chavarria, David Stuver, Zach Boss

Senior Design Project For Engineers

The goal of this design was to develop an extreme altitude rescue helicopter capable of retrieving hikers stranded on top of Mount Everest. Using the Eurocopter AS350 as a baseline, a conceptual model was produced that is fully capable of hovering and delivering forward flight at the desired altitude of 8,848 meters. Combined blade element momentum theory, proper airfoil selection, and forward flight calculations were utilized in order to optimize the rotor for the given flight conditions on top of Mount Everest. Conceptual fluid dynamics and CAD modeling aided in the process of visually designing the fuselage and rotor. Not …


New Design Of An Electronic Power System For The Cosmic X-Ray Background Nanosatellite-3, Christian Joel Ortiz-Huertas Apr 2019

New Design Of An Electronic Power System For The Cosmic X-Ray Background Nanosatellite-3, Christian Joel Ortiz-Huertas

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Christian Joel Ortiz Huertas on April 24, 2019.


An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan Mar 2019

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …


An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan Mar 2019

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …


An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan Mar 2019

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …


Incidence Of An Astronaut Not Sealing The Pressure Garment Visor On Reentry, Cameron M. Smith, Trent Tresch Mar 2019

Incidence Of An Astronaut Not Sealing The Pressure Garment Visor On Reentry, Cameron M. Smith, Trent Tresch

Journal of Human Performance in Extreme Environments

Audiovisual records of a Project Mercury pilot’s activities during an orbital flight indicate that his visor was left open during reentry and descent to the sea surface, phases of flight during which cabin pressure loss was to be mitigated by suit pressurization; however, the suit could not have been pressurized with the visor open. Thus, for a presently unknown reason, a critical safety step—sealing the visor and making a pressure suit integrity test before reentry—was overlooked in this flight. Later, Space Shuttle flights were carried out with visors unsealed for much of the launch and landing phases, with the false …


Nasa Mars Greenhouse, Alexa Escalona, Thomas Lee Hodsden Iii, Zoe Ault Rivas, Grace Genszler, Morgan Mcgonagle, David Dick, Christopher Yu, Peter Mahoney Jr. Mar 2019

Nasa Mars Greenhouse, Alexa Escalona, Thomas Lee Hodsden Iii, Zoe Ault Rivas, Grace Genszler, Morgan Mcgonagle, David Dick, Christopher Yu, Peter Mahoney Jr.

ENGS 89/90 Reports

NASA conducts an annual BIG (Breakthrough, Innovative, Game-Changing) Idea Challenge for university-level students across the country. This ENGS 90 Group competed and was chosen as one of the five finalists with a low-cost, low-risk design of an inflatable greenhouse which can support a human mission to Mars. This greenhouse features a hydroponic growing system to grow eight different food crops to meet the nutritional requirements of a four-person crew.


Lasers For Communication And Coordination Control Of Spacecraft Swarms, Himangshu Kalita, Leonard Dean Vance, Vishnu Reddy, Jekan Thanga Feb 2019

Lasers For Communication And Coordination Control Of Spacecraft Swarms, Himangshu Kalita, Leonard Dean Vance, Vishnu Reddy, Jekan Thanga

Space Traffic Management Conference

Swarms of small spacecraft offer whole new capabilities in Earth observation, global positioning and communications compared to a large monolithic spacecraft. These small spacecraft can provide bigger apertures that increase gain in communication antennas, increase area coverage or effective resolution of distributed cameras and enable persistent observation of ground or space targets. However, there remain important challenges in operating large number of spacecrafts at once. Current methods would require a large number of ground operators monitor and actively control these spacecraft which poses challenges in terms of coordination and control which prevents the technology from scaled up in cost-effective manner. …


Project Atlas: A Mobile Universal Rocket Engine Test Stand, Collin Mickels, Conrad H. Wright, Noah Soderquist, Alona Prokofieva, Sattar Panahandehgar, Naveen Sri Uddanti, Alcuin Rajan Jan 2019

Project Atlas: A Mobile Universal Rocket Engine Test Stand, Collin Mickels, Conrad H. Wright, Noah Soderquist, Alona Prokofieva, Sattar Panahandehgar, Naveen Sri Uddanti, Alcuin Rajan

Student Works

Project Atlas is a mobile, trailer-mounted, rocket engine test stand developed by Experimental Rocket Propulsion Lab (ERPL) at Embry-Riddle Aeronautical University’s Daytona Beach, Florida campus. The integrated test stand and automated data-acquisition and control system supports ERPL’s multitude of engine research projects, including bipropellant liquid and hybrid rocket engines. The need for an integrated universal mobile test stand stems from the inability to conduct frequent test fires on campus due to Class-3 airspace and liability issues. The test stand is designed as a horizontal thrust structure utilizing a dual flame duct to redirect and cancel reaction forces acting upon the …


A Systems And Cost Analysis Of Human Rated Mars Entry, Descent, And Landing Vehicles, Paul Daniel Friz Jan 2019

A Systems And Cost Analysis Of Human Rated Mars Entry, Descent, And Landing Vehicles, Paul Daniel Friz

Doctoral Dissertations

"Cost is one of the biggest obstacles to sending humans to Mars. However, spacecraft costs are typically not taken into consideration until after the preliminary vehicle and mission concepts have been designed. Once costs have been estimated, managers and project teams often lack confidence that the final cost of the mission will match the preliminary estimates. The present work provides a robust methodology for using cost as a valid metric early in the design phase of future human Mars Entry, Descent, and Landing (EDL) vehicles. This is done in three parts. First, state of the art parametric costing methods are …


Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek Jan 2019

Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental …


The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D Jan 2019

The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents the application of Signal Detection Theory (SDT) concepts to the certification of optional systems that provide operational or system safety benefits. The method and analysis yield quantitative requirements for the system performance that account for the risks and benefits of the potential system. This is in contrast to the standard certification approach which only focuses on Failure Conditions, and does not examine potential system benefits. A case study of an aircraft spotter on an electronic moving map illustrates that substantial safety improvements may be achieved even with the relatively low levels of software reliability associated with Commercial …


Effects Of A Hand Luggage Guiding System On Airplane Boarding Time And Passenger Experience, Mirte Vendel, Sagar Dangal, Jessica Coppens, Suzanne Hiemstra-Van Mastrigt, Peter Vink Jan 2019

Effects Of A Hand Luggage Guiding System On Airplane Boarding Time And Passenger Experience, Mirte Vendel, Sagar Dangal, Jessica Coppens, Suzanne Hiemstra-Van Mastrigt, Peter Vink

International Journal of Aviation, Aeronautics, and Aerospace

This research investigates whether a hand luggage guiding system in overhead bins decreases boarding time and improves boarding experience during aircraft boarding process. A guiding system was developed which allocates and displays the passengers luggage space in the overhead bin. The allocated space is guided by a light strip in front of the display that blinks when a passenger comes close to their allocated luggage space. This system was tested in a Boeing 737 test fuselage. Compared to regular boarding, a boarding time reduction of 16 to 23 seconds was estimated using the hand luggage guiding system in groups of …


Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr. Jan 2019

Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation around the world has integrated into a global system. As the integration process continues, more aspects and levels of it need to be lead towards the sustainable development of the whole system via advancing strategic management, global communication proficiency, and technological expertise. It becomes essential to enrich global language (English) proficiency with cross-cultural communication competence not only for communication in the air but also for airport security, passenger and cargo services, aircraft and equipage engineering, building, and maintenance. Nowadays lower levels of management need more advanced strategic thinking and problem solving skills, and higher levels of management need global …