Matching Items (25)
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Description

The objective of this report is to discover a skyhook’s ability to change the plane of another spacecraft’s orbit while ensuring that each vehicle’s orbital energy remains constant. Skyhooks are a proposed momentum exchange device in which a tether is attached to a counterweight at one end and at the

The objective of this report is to discover a skyhook’s ability to change the plane of another spacecraft’s orbit while ensuring that each vehicle’s orbital energy remains constant. Skyhooks are a proposed momentum exchange device in which a tether is attached to a counterweight at one end and at the other, a capturing device intended to intercept rendezvousing spacecraft. Trigonometric velocity vector relations, along with objective comparisons to traditionally proposed uses for skyhooks and gravity-assist maneuvers were responsible for the ultimate parameterization of the proposed energy neutral maneuver. From this methodology, it was determined that a spacecraft’s initial relative velocity vector must be perpendicular to, and rotated about the skyhook’s total velocity vector if it is to benefit from an energy neutral plane change maneuver. A quaternion was used to model the rotation of the incoming spacecraft’s relative velocity vector. The potential post-maneuver spacecraft orbits vary in their inclinations depending on the ratio between the skyhook and spacecraft’s total velocities at the point of rendezvous as defined by the parameter called the alpha criterion. For many cases, the proposed maneuver will serve as a desirable alternative to currently practiced propulsive plane change methods because it does not costly require a substantial amount of propellant. The proposed maneuver is also more accessible than alternative methods that involve gravity-assist and aerodynamic forces. Additionally, by avoiding orbital degradation through the achievement of unchanging total orbital energy, the skyhook will be able to continually and self-sustainably provide plane changes to any spacecraft that belong to orbits that abide by the identified parameters.

ContributorsSeale, Ryan (Author) / Peet, Matthew (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
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Description
Advancements to a dual scale Large Eddy Simulation (LES) modeling approach for immiscible turbulent phase interfaces are presented. In the dual scale LES approach, a high resolution auxiliary grid, used to capture a fully resolved interface geometry realization, is linked to an LES grid that solves the filtered Navier-Stokes equations.

Advancements to a dual scale Large Eddy Simulation (LES) modeling approach for immiscible turbulent phase interfaces are presented. In the dual scale LES approach, a high resolution auxiliary grid, used to capture a fully resolved interface geometry realization, is linked to an LES grid that solves the filtered Navier-Stokes equations. Exact closure of the sub-filter interface terms is provided by explicitly filtering the fully resolved quantities from the auxiliary grid. Reconstructing a fully resolved velocity field to advance the phase interface requires modeling several sub-filter effects, including shear and accelerational instabilities and phase change. Two sub-filter models were developed to generate these sub-filter hydrodynamic instabilities: an Orr-Sommerfeld model and a Volume-of-Fluid (VoF) vortex sheet method. The Orr-Sommerfeld sub-filter model was found to be incompatible with the dual scale approach, since it is unable to generate interface rollup and a process to separate filtered and sub-filter scales could not be established. A novel VoF vortex sheet method was therefore proposed, since prior vortex methods have demonstrated interface rollup and following the LES methodology, the vortex sheet strength could be decomposed into its filtered and sub-filter components. In the development of the VoF vortex sheet method, it was tested with a variety of classical hydrodynamic instability problems, compared against prior work and linear theory, and verified using Direct Numerical Simulations (DNS). An LES consistent approach to coupling the VoF vortex sheet with the LES filtered equations is presented and compared against DNS. Finally, a sub-filter phase change model is proposed and assessed in the dual scale LES framework with an evaporating interface subjected to decaying homogeneous isotropic turbulence. Results are compared against DNS and the interplay between surface tension forces and evaporation are discussed.
ContributorsGoodrich, Austin Chase (Author) / Herrmann, Marcus (Thesis advisor) / Dahm, Werner (Committee member) / Kim, Jeonglae (Committee member) / Huang, Huei-Ping (Committee member) / Kostelich, Eric (Committee member) / Arizona State University (Publisher)
Created2023
Description

Today, the vision of Commercial Supersonic Travel is often dreamed possible with innovation. Modern tech-business plans to reinvent commercial SuperSonic Transport (SST), while gaining reliable venture capital investment and proactive social backing. However, the concept’s global viability remains questionable, as regulation opposes its integrability. As a result, SST has become

Today, the vision of Commercial Supersonic Travel is often dreamed possible with innovation. Modern tech-business plans to reinvent commercial SuperSonic Transport (SST), while gaining reliable venture capital investment and proactive social backing. However, the concept’s global viability remains questionable, as regulation opposes its integrability. As a result, SST has become industrially forgotten. This research paper challenges the neglect of SST through routing optimizations derived from an industry’s collective research, while outlining decisive use-cases. Initially, this paper describes the difficulty in SST’s integration through its logistical tasks, demanding designs, and lacking efficiency. After that, the paper defines an optimization strategy, through software-analyzed flight paths, for overall supersonic operations. This strategy was proven to shorten established SST flights by 6%, while enabling the implementation of newfound SST paths. Here, optimization averaged 3.3% on density-derived routes and 5.4% on software-derived routes. More importantly, this paper demonstrated routing optimization enables MACH 1.6 aircraft to achieve MACH 2 flight times. Further, this paper attempts to justify SST through an analysis of its market, financials, and social perspectives. With that, the paper justifies an ideal SST customer earns 630$/hr, while such measurements vary amongst flight types. Finally, this paper conceptualizes that SST, with optimization, promises a noteworthy business, while developments in aircraft designs may revamp the aerospace industry completely.

ContributorsDe Roo, Matisse (Author) / Takahashi, Timothy (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
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Description
This thesis describes the extension of an aircraft-style time-step integrating mission performance simulation to address aero-spaceplane design challenges. The result is a computationally lean program compatible with current Multi-Disciplinary Optimization schemes to assist in the conceptual design of hypersonic vehicles. To do this the starting aircraft style “Mission Code” required

This thesis describes the extension of an aircraft-style time-step integrating mission performance simulation to address aero-spaceplane design challenges. The result is a computationally lean program compatible with current Multi-Disciplinary Optimization schemes to assist in the conceptual design of hypersonic vehicles. To do this the starting aircraft style “Mission Code” required enhancements to the typical point-mass simulation for high altitude and high Mach flight. Stability parameters and the rigid-body modes of Short-Period and Dutch-Roll are tracked to understand time-domain limits to aerodynamic control, along with monitoring the Lateral Control Departure Parameter to ensure that the aircraft is not prone to spin. Additionally, experience has shown that for high Mach Number flight designers must consider aerothermodynamic effects early in the vehicle design process, and thus, an engineering level aerothermodynamic model is included. Comparisons to North American X-15 flight test datasets demonstrate the validity of this method in that application, and trade studies conducted show the utility of this application.
ContributorsGriffin, Jack Aidan (Author) / Takahashi, Timothy (Thesis advisor) / Dahm, Werner (Committee member) / Rodi, Patrick (Committee member) / Arizona State University (Publisher)
Created2022
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Description
This thesis investigates the configurations needed to demonstrate positive lateraldirectional controllability across the flight envelope of a hypersonic vehicle. Itexamines the NASA Space Shuttle Orbiter as a baseline reference configuration, as it was a successful hypersonic vehicle. However, the Orbiter had limited high-speed maneuvering capability; it relied on reaction-control jets to augment

This thesis investigates the configurations needed to demonstrate positive lateraldirectional controllability across the flight envelope of a hypersonic vehicle. Itexamines the NASA Space Shuttle Orbiter as a baseline reference configuration, as it was a successful hypersonic vehicle. However, the Orbiter had limited high-speed maneuvering capability; it relied on reaction-control jets to augment controllability due to a strong tendency for its aerodynamics to “control couple.” It was seen that many problems associated with the control of the hypersonic Orbiter are due to its slender configuration. This work relies upon the Evolved-Bihrle-Weissman chart as an accurate indicator of lateral-directional stability and controllability. The also explores variant configurations of larger wing tip verticals to explore what configuration changes are needed to reduce dependence on reaction controls.
ContributorsHoopes, Connor Smith (Author) / Takahashi, Timothy (Thesis advisor) / Dahm, Werner (Committee member) / Perez, Ruben (Committee member) / Arizona State University (Publisher)
Created2023
Description
In order to make space more accessible and cost effective, rapid reusability is required for launch vehicles and spacecraft. Lunar Dust has proven to be an unpredictable and problematic factor in past lunar exploration missions by damaging equipment and spacesuits. Vital components found in rocket engines are also damaged during

In order to make space more accessible and cost effective, rapid reusability is required for launch vehicles and spacecraft. Lunar Dust has proven to be an unpredictable and problematic factor in past lunar exploration missions by damaging equipment and spacesuits. Vital components found in rocket engines are also damaged during decent and operation on the lunar surface. This project is a collection research and designs of a novel system that protects the main components of rocket engines in order to allow engines to be reusable and allow for space travel more sustainable. This system will also add to mission safety and will be critical for humanity's future presence on the Moon.
ContributorsNaguib, Sameer (Author) / Bhate, Dhruv (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2022-12
ContributorsNaguib, Sameer (Author) / Bhate, Dhruv (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2022-12
ContributorsNaguib, Sameer (Author) / Bhate, Dhruv (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2022-12
ContributorsNaguib, Sameer (Author) / Bhate, Dhruv (Thesis director) / Dahm, Werner (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2022-12
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Description
This thesis aims to determine how finite wing aerodynamic loads change in proximity to the ground. In this study, the primary design tool is an inviscid panel method code, VORLAX. The validation tool is a commercial volume grid CFD package, ANSYS FLUENT. I use VORLAX to simulate wings with different

This thesis aims to determine how finite wing aerodynamic loads change in proximity to the ground. In this study, the primary design tool is an inviscid panel method code, VORLAX. The validation tool is a commercial volume grid CFD package, ANSYS FLUENT. I use VORLAX to simulate wings with different incidences and aspect ratios to look at how ground effect impacts spanwise loading and incipient flow separation. Then the results were compared to widely published equations such as McCormick, Torenbeek, and Hoerner & Borst. Because I found that these “famous” equations function best only for specific conditions, I propose a new empirical equation to estimate ground effect lift as a function of aspect ratio and incidence. Using Stratford’s method to predict signs of flow separation in the inviscid solutions, I found that variations in the height above the ground were not significant enough to change the stall angle of low aspect ratio wings. I did find early signs of flow separation with increasing aspect ratio. I observe significant changes in spanwise loading when in ground effect; as I narrow the gap, the transverse loading builds higher near the center of the wing. These effects were more apparent in wings with smaller aspect ratio; higher aspect ratio wings experience a higher loading gradient near the tips in proximity to the ground. I found that high aspect ratio wings have a smaller stall angle compared to that of lower aspect ratio wings; these trends are consistent between the potential flow solution and the volume grid CFD viscous solution.
ContributorsValenzuela, Jose Vanir (Author) / Takahashi, Timothy (Thesis advisor) / Dahm, Werner (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2024