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Thrust Augmented Nozzle For A Hybrid Rocket With A Helical Fuel Port, Joel H. Marshall 2018 Utah State University

Thrust Augmented Nozzle For A Hybrid Rocket With A Helical Fuel Port, Joel H. Marshall

All Graduate Theses and Dissertations

A thrust augmented nozzle for hybrid rocket systems is investigated. The design lever-ages 3-D additive manufacturing to embed a helical fuel port into the thrust chamber of a hybrid rocket burning gaseous oxygen and ABS plastic as propellants. The helical port significantly increases how quickly the fuel burns, resulting in a fuel-rich exhaust exiting the nozzle. When a secondary gaseous oxygen flow is injected into the nozzle downstream of the throat, all of the remaining unburned fuel in the plume spontaneously ignites. This secondary reaction produces additional high pressure gases that are captured by the nozzle and significantly increases the ...


Nanoindentation Study Of Corrosion-Induced Grain Boundary Degradation In A Pipeline Steel, Denizhan Yavas, Pratyush Mishra, Abdullah Alshehri, Pranav Shrotriya, Kurt R. Hebert, Ashraf F. Bastawros 2018 Iowa State University

Nanoindentation Study Of Corrosion-Induced Grain Boundary Degradation In A Pipeline Steel, Denizhan Yavas, Pratyush Mishra, Abdullah Alshehri, Pranav Shrotriya, Kurt R. Hebert, Ashraf F. Bastawros

Aerospace Engineering Publications

High-strength low-alloy steels used for oil and gas pipelines are vulnerable to intergranular stress corrosion cracking in moderately alkaline soils. The mechanism of corrosion-induced embrittlement under such conditions is not yet understood. Nanoindentation was used to detect localized degradation of mechanical properties near internal grain boundaries of X-70 steel undergoing intergranular corrosion at active dissolution potentials at pH 8.2. The measurements identified a one-micron thick mechanically-degraded layer with 25% reduced hardness near corroded grain boundaries. It is suggested that the corrosion process may introduce an active softening agent, possibly non-equilibrium lattice vacancies generated by oxidation.


Inherent And Model-Form Uncertainty Analysis For Cfd Simulation Of Synthetic Jet Actuators, Daoru Frank Han, Serhat Hosder 2018 Missouri University of Science and Technology

Inherent And Model-Form Uncertainty Analysis For Cfd Simulation Of Synthetic Jet Actuators, Daoru Frank Han, Serhat Hosder

Serhat Hosder

A mixed (aleatory and epistemic) uncertainty quantification (UQ) method was applied to computational uid dynamics (CFD) modeling of a synthetic jet actuator. A test case, (ow over a hump model with synthetic jet actuator control) from the CFDVAL2004 work-shop was selected to apply the Second-Order Probability framework implemented with a stochastic response surface obtained from Quadrature-Based Non-Intrusive Polynomial Chaos (NIPC). Three uncertainty sources were considered: (1) epistemic (model-form) uncertainty in turbulence model, (2) aleatory (inherent) uncertainty in free stream veloc-ity and (3) aleatory uncertainty in actuation frequency. Uncertainties in both long-time averaged and phase averaged quantities were quantified using a ...


Uncertainty Quantification Integrated To The Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder 2018 Missouri University of Science and Technology

Uncertainty Quantification Integrated To The Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder

Serhat Hosder

The Point Collocation Non-Intrusive Polynomial Chaos (NIPC) method has been applied to two stochastic synthetic jet actuator problems used as test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. In Case1 where the synthetic jet is issued into quiescent air, the NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field, due to the uniformly distributed uncertainty introduced in the amplitude and frequency of the oscillation of the piezo-electric membrane. Fifth order NIPC ...


Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Frank W. Liou, Joseph William Newkirk 2018 Missouri University of Science and Technology

Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Frank W. Liou, Joseph William Newkirk

Joseph William Newkirk

Laser deposition is an effective process for mold and die repair. In order to improve the part repair quality??the process impact on thermal diffusivity and thermal conductivity needs to be understood for laser deposited, welded and virgin H13. In this paper, H13 tool steel samples were made by laser deposition, welding and virgin H13 and then cut into pieces. Experiments were conducted to investigate the thermal diffusivity and conductivity. A laser flash method is used to test these samples. The future work and opportunities are also summarized. Keywords: Laser Flash, laser deposition, tool steel, H13


Base Pressure Control Using Micro-Jets In Supersonic Flow Regimes, Vigneshvaran Sethuraman, Sher Afghan Khan 2018 Monash University Malaysia

Base Pressure Control Using Micro-Jets In Supersonic Flow Regimes, Vigneshvaran Sethuraman, Sher Afghan Khan

International Journal of Aviation, Aeronautics, and Aerospace

Base pressure plays a vital role in aerospace-related applications and its control is essential in reduction of drag and improving fuel consumption. Low pressure at the base of Rockets, Missiles, bombs and shells are a very common problem happening at transonic and supersonic speeds. In most of the cases there is a significant dip in pressure at the base region which will have implications on the design of aerospace vehicles. This paper presents an experimental investigation carried out for flow control at supersonic regimes. Experiments were conducted to measure the base pressure in the base region and wall pressure distribution ...


Subjectivity In Failure Mode Effects Analysis (Fmea) Severity Classification Within A Reliability Centered Maintenance (Rcm) Context, Marc Banghart, Kari Babski-Reeves, Linkan Bian, Lesley Strawderman 2018 ERAU

Subjectivity In Failure Mode Effects Analysis (Fmea) Severity Classification Within A Reliability Centered Maintenance (Rcm) Context, Marc Banghart, Kari Babski-Reeves, Linkan Bian, Lesley Strawderman

International Journal of Aviation, Aeronautics, and Aerospace

This research paper investigated subjectivity in the severity rating of failure modes within a risk analysis process. Although several risk analysis processes can be utilized, the study considered the application of Failure Modes Effects Analysis (FMEA) or Failure Modes Effects and Criticality Analysis (FMECA) due to its common use within the Aerospace Industry. The study investigated both differences in severity selection given varying amounts of experience as well as any association between severity selection and the provided input information. The main goal of the research was to investigate the impact of data quality on severity selection and to identify factors ...


Assessment And Comparison Of Aviation Manufacturing Industries Throughout Mexico And Brazil, Omar E. Morsi, Kelly A. Whealan-George, Aaron D. Clevenger 2018 Embry-Riddle Aeronautical University

Assessment And Comparison Of Aviation Manufacturing Industries Throughout Mexico And Brazil, Omar E. Morsi, Kelly A. Whealan-George, Aaron D. Clevenger

International Journal of Aviation, Aeronautics, and Aerospace

This literature review serves to provide insight and understanding in regards to the evolving aviation manufacturing industry throughout the globe and more specifically, Mexico and Brazil. Increased demand for aircraft units both in the commercial and private sectors have led to unprecedented expansions in aircraft manufacturing across the industry. In order to illuminate certain potentials and current growth levels of such industries, this review will delve into an array of information and specifications in regards to economic, political, and cultural influences throughout both Mexican and Brazilian markets respectively. In conclusion, the review will identify the transformation of an aviation manufacturing ...


Utm, Atm, Stm… Slices Of The Sky?, Ruth E. Stilwell 2018 Norwich University

Utm, Atm, Stm… Slices Of The Sky?, Ruth E. Stilwell

Space Traffic Management Conference

UTM, ATM, STM… slices of the sky?

This paper will examine the functional differences between Unmanned Aircraft Traffic Management Systems, Air Traffic Management Systems, and Space Traffic Management. Understanding both the similarities between the systems and the different functional requirements of each concept is critical in the discussion and development of STM. While there are many commonalities in each area, it is important to understand how the different environments affect the ability to develop policies, procedure and technologies to manage the vehicles operating in the distinct environment. Both technical and legal frameworks will be discussed.

Building a conceptual framework for ...


Responsible Behavior For Constellations And Clusters, Darren McKnight, Jonathan Rosenblatt, Darren Garber 2018 Integrity Applications, Inc.

Responsible Behavior For Constellations And Clusters, Darren Mcknight, Jonathan Rosenblatt, Darren Garber

Space Traffic Management Conference

Many large constellations are being considered for deployment over the next ten years into low earth orbit (LEO). This paper seeks to quantify the risks that these constellations pose to the debris environment, the risks that the debris environment poses to these constellations, and the risks that these constellations pose to themselves. The three representative constellations examined in detail in this paper are operated (or planned to be operated) by Spire Global, Iridium, and OneWeb. This paper provides a balanced risk analysis including collision risk, operational risk, and non-adherence risk. For perspective, the risk posed by these economically useful constellations ...


Unmanned Aerial Systems: Research, Development, Education & Training At Embry-Riddle Aeronautical University, Michael P. Hickey 2018 Embry-Riddle Aeronautical University

Unmanned Aerial Systems: Research, Development, Education & Training At Embry-Riddle Aeronautical University, Michael P. Hickey

Publications

With technological breakthroughs in miniaturized aircraft-related components, including but not limited to communications, computer systems and sensors, state-of-the-art unmanned aerial systems (UAS) have become a reality. This fast-growing industry is anticipating and responding to a myriad of societal applications that will provide new and more cost-effective solutions that previous technologies could not, or will replace activities that involved humans in flight with associated risks.

Embry-Riddle Aeronautical University has a long history of aviation-related research and education, and is heavily engaged in UAS activities. This document provides a summary of these activities, and is divided into two parts. The first part ...


The Aerodynamic Effects On A Cornering Ahmed Body, James Keogh, Tracie Barber, Sammy Diasinos, Graham Doig 2018 University of New South Wales

The Aerodynamic Effects On A Cornering Ahmed Body, James Keogh, Tracie Barber, Sammy Diasinos, Graham Doig

Dr. Graham Doig

As a vehicle travels through a corner, the flowfield observed from the vehicle׳s frame of reference becomes curved. This condition results in the relative flow angle and freestream velocity changing both across the width and along the length of the body. Wall-resolved Large Eddy Simulations were used to simulate a simple vehicle shape through three different radii corners. The variable flow angle and acceleration affected the pressure distribution along either side of the body and caused an increase in the size of the outboard C-pillar vortex, and an inboard decrease. Furthermore, an outboard extension of the separation bubble at ...


The Effects Of Simplifications On Isolated Wheel Aerodynamics, Sammy Diasinos, Tracie Barber, Graham Doig 2018 University of New South Wales

The Effects Of Simplifications On Isolated Wheel Aerodynamics, Sammy Diasinos, Tracie Barber, Graham Doig

Dr. Graham Doig

In order to study the aerodynamic forces and flow features of rotating wheels, compromises and simplifications are often made in wind tunnel testing, and more frequently so in numerical modelling. A CFD approach similar to that commonly used in industry was utilised to investigate common assumptions involving; the influence of geometric fidelity in wheel hub regions, ground representation, the modelling of the contact patch, and the effects of rotation on separation. It was found that the separation and wake characteristics were strongly influenced by the rotation of the wheel; the separation point changed by as much as 90% compared to ...


The Onset For Compressibility Effects For Aerofoils In Ground Effect, G. Doig, T.J. Barber, E. Leonardi, A.J. Neely 2018 University of New South Wales

The Onset For Compressibility Effects For Aerofoils In Ground Effect, G. Doig, T.J. Barber, E. Leonardi, A.J. Neely

Dr. Graham Doig

The influence of flow compressibility on a highly-cambered inverted aerofoil in ground effect is presented, based on two-dimensional computational studies. This type of problem has relevance to open-wheel racing cars, where local regions of high-speed subsonic flow form under favourable pressure gradients, even though the maximum freestream Mach number is typically considerably less than Mach 0.3. An important consideration for CFD users in the field is addressed in this paper, the freestream Mach number at which flow compressibility significantly affects aerodynamic performance. More broadly, for aerodynamicists, the consequences of this are also considered. Comparisons between incompressible and compressible CFD ...


Techniques For Aerodynamic Analysis Of Cornering Vehicles, James Keogh, Tracie J. Barber, Sammy Diasinos, Graham Doig 2018 University of New South Wales

Techniques For Aerodynamic Analysis Of Cornering Vehicles, James Keogh, Tracie J. Barber, Sammy Diasinos, Graham Doig

Dr. Graham Doig

When a vehicle travels through a corner it can experience a significant change in aerodynamic performance due to the curved path of its motion. The yaw angle of the flow will vary along its length and the relative velocity of the flow will increase with distance from the central axis of its rotation. Aerodynamic analysis of vehicles in the cornering condition is an important design parameter, particularly in motorsport. Most racing-cars are designed to produce downforce that will compromise straight-line speed to allow large gains to be made in the corners. Despite the cornering condition being important, aerodynamicists are restricted ...


Suppressing Restricted Shock Separation In A Subscale Rocket Nozzle Using Contour Geometry, K. Schomberg, J. Olsen, A. J. Neely, Graham Doig 2018 University of New South Wales

Suppressing Restricted Shock Separation In A Subscale Rocket Nozzle Using Contour Geometry, K. Schomberg, J. Olsen, A. J. Neely, Graham Doig

Dr. Graham Doig

The use of a thrust-optimized contour (TOC) for the supersonic nozzle in a rocket engine will inherently maximize the propulsive efficiency and payload capacity of the entire launch system. A TOC can be approximated using a skewed parabola, commonly referred to as a thrust-optimized parabola (TOP), and the TOP contour can be manipulated to avoid undesirable flow separation during low-altitude operation by increasing the static wall pressure at the expense of thrust (approximately 0.1 0.2%). For this reason, a TOP design is often used in nozzles with a high area ratio, such as those used in the Vulcain ...


Reducing Transonic Wind Tunnel Sting Interference Effects For Concealed Store Release Testing, Graham Doig, Goran Bogdan, Kaveh R. Kabir, Murray R. Snyder 2018 California Polytechnic State University, San Luis Obispo

Reducing Transonic Wind Tunnel Sting Interference Effects For Concealed Store Release Testing, Graham Doig, Goran Bogdan, Kaveh R. Kabir, Murray R. Snyder

Dr. Graham Doig

Internal weapons bays are becoming increasingly common on aircraft for reasons of stealth and aerodynamic performance, and will be even more prevalent on coming generations of unmanned combat aerial vehicles (UCAVs). Wind tunnel testing of store releases to assess forces and moments for safety and clearance must be conducted with a store mounted to an angled strut rather than a conventional rear sting, to allow the full range of motion as the store “drops” from inside the aircraft. Interference from this strut can disrupt the flowfields and thus the reliability of moments obtained, and therefore an investigation was conducted to ...


Interactions Of Shock Tube Exhaust Flows With Laminar And Turbulent Flames, Joel E.C. Chan, Paul M. Giannuzzi, Kaveh R. Kabir, Michael J. Hargather, Graham Doig 2018 University of New South Wales

Interactions Of Shock Tube Exhaust Flows With Laminar And Turbulent Flames, Joel E.C. Chan, Paul M. Giannuzzi, Kaveh R. Kabir, Michael J. Hargather, Graham Doig

Dr. Graham Doig

The interactions of flow features emitting from open-ended shock tubes with free-standing propane flames have been investigated using high-speed schlieren imaging and high-frequency pressure measurements, with additional data from validated numerical modeling. Both compressed air-driven interactions with non-pre-mixed laminar diffusion flames (small-scale) and explosively-driven interactions with turbulent non-pre-mixed turbulent flames (large-scale) were tested for various flame locations and shock tube stagnation pressures (and therefore Mach numbers). In the small-scale tests it was observed that the flames were not significantly influenced by the passage of either the initial shock if placed close to the tube exit, or the weaker pressure waves ...


On The Interaction Of A Racing Car Front Wing And Exposed Wheel, S. Diasinos, G. Doig, T.J. Barber 2018 Macquarie University

On The Interaction Of A Racing Car Front Wing And Exposed Wheel, S. Diasinos, G. Doig, T.J. Barber

Dr. Graham Doig

A numerical investigation of generic open-wheel racing car wing and wheel geometry has been conducted, using original sub-scale experimental data for validation. It was determined that there are three main interactions that may occur, identifiable by the path that the main and secondary wing vortices take around the wheel. Interaction ‘A’ occurs when the main and secondary wing vortices both travel outboard of the wheel; interaction ‘B’ is obtained when only the main wing vortex passes inboard of the wheel; while interaction ‘C’ sees both wing vortices travel inboard of the wheel. The different interactions are achieved when geometric changes ...


Explosive-Driven Shock Wave And Vortex Ring Interaction With A Propane Flame, P. Giannuzzi, M. J. Hargather, Graham Doig 2018 New Mexico Institute of Mining and Technology

Explosive-Driven Shock Wave And Vortex Ring Interaction With A Propane Flame, P. Giannuzzi, M. J. Hargather, Graham Doig

Dr. Graham Doig

Experiments were performed to analyze the interaction of an explosively driven shock wave and a propane flame. A 30 g explosive charge was detonated at one end of a 3-m-long, 0.6-m-diameter shock tube to produce a shock wave which propagated into the atmosphere. A propane flame source was positioned at various locations outside of the shock tube to investigate the effect of different strength shock waves. High-speed retroreflective shadowgraph imaging visualized the shock wave motion and flame response, while a synchronized color camera imaged the flame directly. The explosively driven shock tube was shown to produce a repeatable shock ...


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