Organizational Unit:
Daniel Guggenheim School of Aerospace Engineering

Permanent Link
https://hdl.handle.net/1853/70742
Research Organization Registry ID
Description
Previous Names
Parent Organization
Parent Organization
Organizational Unit
Includes Organization(s)
ArchiveSpace Name Record
https://finding-aids.library.gatech.edu/agents/corporate_entities/106

Filters

352
352
Reset filters

Settings
Item Type: Publication × search.filters.applied.f.resourcesubtype: Technical Report ×

Publication Search Results

Now showing 1 - 10 of 352
Thumbnail Image
Item

CFD Study of an Over-Wing Nacelle Configuration

2018-10-05 , Berguin, Steven H. , Renganathan, Sudharshan Ashwin , Ahuja, Jai , Chen, Mengzhen , Perron, Christian , Tai, Jimmy C. M. , Mavris, Dimitri N.

Engine bypass ratio (BPR) has grown significantly over the years, due to a desire for increased efficiency, and the large fan diameters that have resulted are forcing the engines so close to the wing that there is no room left for them to grow any larger due to ground clearance constraints. As BPR increases even further in the future, conventional Under-Wing Nacelle (UWN) installations will therefore no longer be possible without drastic modification of the wing and landing gear. Over-Wing nacelle concepts solve this problem by offering a convenient installation for high BPR turbofans and, additionally, offer the potential to mitigate community noise through engine noise shielding using the wing as a shield. However, OWN has historically warranted concern about unacceptably high drag levels at transonic speeds and the purpose of this research was to determine whether or not drag can be improved enough to take advantage of the aforementioned cross-disciplinary benefits. To do so, three studies were conducted: study 1 conducted a simple nacelle sweep in order to identify and visualize the physical mechanisms driving the configuration, study 2 then conducted a sensitivity analysis in order to understand important design variables and, finally, study 3 performed single point optimization for a trailing edge OWN concept. Overall, results suggests that OWN drag can be improved to levels commensurate with its Under-Wing Nacelle (UWN) counterpart. However, limitations of the analysis tools employed for this research (in the area of shape optimization) were insufficient to outperform the UWN baseline. Such limitations were successfully overcome by modern OWN concepts, such as the Honda Business Jet and the military Lockheed HWB for air mobility missions. Overall, it is therefore the authors' opinion that either leading-edge or trailing-edge mounted OWN configurations are concepts worth investigating further for civil transport applications.

View
Thumbnail Image
Item

Dynamic modeling of plasma effects during multi-phase detonations near a surface and/or in a magnetic field

2013-12 , Menon, Suresh , Schulz, Joseph

A multi-physics model has been developed to simulate detonations and condensed-phase explosions in the presence of an external electromagnetic field. To simulate these effects, models for high-temperature gas physics, plasma-production, dispersed-phase mixing, and turbulence have been implemented within the framework of a numerical method capable of simulating magnetohydrodynamic (MHD) flows. This research has leveraged past work in MHD flows, detonations, and turbulence-chemistry interactions to study multi-scale detonation-plasma-field interactions, and has furthered the understanding of many key physical processes of these flows. This work targeted three main basic science objectives: the study of plasma-production by detonations and condensed-phase explosions, the study of MHD instabilities and turbulence relevant to post-detonation flows, and the study of how a detonation is affected by the presence of a magnetic field. Simulations indicate that gaseous detonation waves generate a weakly ionized plasma in the post-detonation region. The average electrical conductivity in the post-detonation flow, however, is of the order of 10-3 S/m, and practical engineering applications involving the use of MHD forces to manipulate the flow for generation of electrical power, propulsive thrust, etc., require higher levels of electrical conductivity. Simulations of mixtures seeded with particles of a low ionization potential show a substantial increase the flow's electrical conductivity. The presence of these particles can adversely affect the detonation propagation. The physics of how an electromagnetic field interacts with the conducting products of a detonation, and how that interaction might affect the stability and propagation of the detonation wave is systematically studied. The magnetic field applied in the direction of detonation propagation affects the detonation through a combined effect of Joule heating and Lorentz force, in some cases altering the cellular structure of the detonation completely by reducing the half-reaction zone thickness. Basic studies of the Richtmyer-Meshkov instability, an important mechanism for the transition to turbulence in explosions, are used to elucidate several salient features of these types of MHD flows. Namely, simulations show that the presence of a dispersed phase alters the mixing growth-rates of the instability, and furthermore, an applied magnetic field is shown to either suppress or enhance fluid mixing.

View
Thumbnail Image
Item

On-demand aircraft conceptual design and development

2013-01 , German, Brian J.

View
Thumbnail Image
Item

Hybrid solution-adaptive unstructured Cartesian method for large-eddy simulation of detonation in multi-phase turbulent reactive mixtures

2012-03 , Menon, Suresh , Gallagher, Timothy , Muralidharan, Balaji

A class of problems of both great fundamental interest and practical relevance is in the field of highly compressible turbulent flows of multi-fluids. Shock interaction with turbulence and/or flames have many practical applications and require advanced computational techniques. This report summarizes the work done to date to develop methods and algorithms for hybrid structured-unstructured methods in large-eddy simulations (LES). Particular emphasis is given to efficiency and accuracy while using techniques applicable to solution-adaptive approaches. The formulation and algorithm for statically refined grids for DNS and LES is shown to be robust and allows rapid inclusion in existing solvers with a minimal change in code base while also ensuring compatibility with existing features. Extensions to solution-adaptive techniques from the static approach are discussed. The application of the method to numerous flow examples demonstrates the capability and robustness of the method. Finally, an adaptive Cartesian method using level-sets and cut-cells to solve the interactions of complex, deforming and reacting bodies in a compressible flow field is developed and validated.

View
Thumbnail Image
Item

Orion Capsule Launch Abort System Analysis

2016 , Scogin, Tyler , Lacerda, Michel , Marshall, Jordan

The objective of this report is to provide an analysis the Orion spacecraft’s Launch Abort System (LAS). A launch abort system aims to remove the crew away from a failing launch vehicle as soon as possible during the liftoff and ascent phase. A survey of other designs for launch abort was carried out to compare the tower system with integrated retrorockets or ejectable rockets. The Orion LAS undergoes 5 distinct stages including liftoff, reorientation, LAS jettison, parachute deployment, and water landing which can east be tested for loads analysis. A model was created in CATIA V6, and will undergo CFD analysis in STAR-CCM+ and FEA analysis in Abaqus to determine the optimal design parameters for crew safety such as drag coefficient, ballistic coefficient, G-loading due to thrust, and structural loads on the vehicle during flight. Digital Design and Manufacturing Technical Report.

View
Thumbnail Image
Item

Cross fire simulation rig

2013-03 , Zinn, Ben T. , Lubarsky, Eugene

The primary purpose of the project was to investigate the threshold for flame propagation between two combustors of crossfire rig designed to simulate conditions in a GE gas turbine engine.

View
Thumbnail Image
Item

State-of-the-art rotor aerodynamics and shipboard rotorcraft flight simulation

2012-09 , Prasad, Jonnalagadda V. R. , Sankar, Lakshmi N.

View
Thumbnail Image
Item

Feasibility Study to Determine the Economic and Operational Benefits of Utilizing Unmanned Aerial Vehicles (UAVs)

2014-05-06 , Irizarry, Javier , Johnson, Eric N.

This project explored the feasibility of using Unmanned Aerial Systems (UASs) in Georgia Department of Transportation (GDOT) operations. The research team conducted 24 interviews with personnel in four GDOT divisions. Interviews focused on (1) the basic goals of the operators in each division, (2) their major decisions for accomplishing those goals, and (3) the information requirements for each decision. Following an interview validation process, a set of UASs design characteristics that fulfill user requirements of each previously identified division was developed. A “House of Quality” viewgraph was chosen to capture the relationships between GDOT tasks and potential UAS aiding those operations. As a result, five reference systems are proposed. The UAS was broken into three components: vehicle, control station, and system. This study introduces a variety of UAS applications in traffic management, transportation and construction disciplines related to DOTs, such as the ability to get real time, digital photographs/videos of traffic scenes, providing a "bird’s eye view" that was previously only available with the assistance of a manned aircraft, integrating aerial data into GDOT drawing software programs, and dealing with restricted or complicated access issues when terrain, area, or the investigated object make it difficult for GDOT personnel to conduct a task. The results of this study could lead to further research on design, development, and field-testing of UAVs for applications identified as beneficial to the Department.

View
Thumbnail Image
Item

Experimental studies of JTECH power generation in a scramjet

2013-03 , Menon, Suresh , Berlette, J. , Scarborough, D.

An analysis of the thermodynamics of the proposed Johnson Thermoelectric Energy Converter (JTEC) device as if it was placed in the walls of the combustor of a supersonic combustion ramjet.

View
Thumbnail Image
Item

A novel augmentor that does not use flame holders to stabilize the combustion process

2012-06 , Zinn, Ben T. , Lubarsky, Eugene , Neumeier, Yedidia , Williams, Aimee

This report describes the process of determining auto-ignition delay of the liquid Jet-A aviation fuel injected in a cross flow of vitiated air. Auto-ignition delays were measured by processing of the time-averaged chemiluminescence images for a range of temperatures from 898-1028K, vitiated oxygen percentages from 9.3% to 12.2%, velocities from 80 – 140 m/s and global Jet-A to, vitiated-air mixture equivalence ratios from φ=0.3 to φ=1.5. It was found that ignition delay increases exponentially from one to ten milliseconds with inverse temperature variation and are more scattered at lower temperatures. The data obtained in this study reveals delay times much shorter than those measured in most of other studies, but with same character of dependence upon the temperature of the flow.

View