Matching Items (7)
Filtering by
- All Subjects: engineering
- All Subjects: Shockwave
Description
This work describes the numerical process developed for use of rocket engine nozzle ejectors. Ejector nozzles, while applied to jet engines extensively, have not been applied to rockets, and have great potential to improve the performance of endoatmospheric rocket propulsion systems. Utilizing the low pressure, high velocity flow in the plume, this secondary structure entrains a secondary mass flow to increase the mass flow of the propulsion system. Rocket engine nozzle ejectors must be designed with the high supersonic conditions associated with rocket engines. These designs rely on the numerical process described in this paper.
ContributorsGibson, Gaines Sullivan (Author) / Wells, Valana (Thesis director) / Takahashi, Timothy (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
Description
This paper describes the research done to attempt to scale up thrusts produced by ionic wind thrusters, or "lifters" to magnitudes needed to power a 2 kg hobbyist remote-control airplane. It includes background information on the Biefeld-Brown effect and the thrust it produces, an experiment that attempted to prove that thrust can be scaled up from smaller ionic wind thrusters to larger scales, and two models predicting thruster geometries and power sources needed to reach these thrusts. An ionic wind thruster could not be created that would power the hobbyist remote as a high-voltage power source with voltage and power high enough could not be obtained. Thrusters were created for the experiment using balsa wood, aluminum foil, and thin copper wire, and were powered using a 30 kV transformer. The thrusters attempted to test for correlations between thrust, electrode length, and current; electric field strength, and thrust; and thrust optimization through opening up air flow through the collector electrode. The experiment was inconclusive as all the thrusters failed to produce measurable thrust. Further experimentation suggests the chief failure mode is likely conduction from the collector electrode to the nearby large conductive surface of the scale.
ContributorsHaug, Andrew James (Author) / White, Daniel (Thesis director) / Takahashi, Timothy (Committee member) / Middleton, James (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Department of Military Science (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The objective of this thesis is to conduct a case study into the Bell X-2, an early supersonic research aircraft utilizing a modern perspective and computational tools. The Bell X-2 was the second in a series of supersonic research aircraft created by Bell Aviation Corporation, designed to help engineers to explore this new region of flight. The goal of the X-2 was to gather data on high Mach Number and high-altitude flight as well as aerodynamic heating. The X-2 had poor lateral stability resulting in it being unstable at high Mach Numbers and moderate angles of attack. The program was full of new and unforeseen technical challenges resulting in many delays and tragedies. The program ended when stability problems resulted in a fatal crash destroying the aircraft and killing the test pilot. This case study addresses the historical background of the program, human influence, the stability problems encountered and conducting a stability analysis of the aircraft. To conduct the stability analysis, the potential flow solver, VORLAX, was used to gather aerodynamic coefficient data of the X-2 and determine if these stability problems could be determined from the data obtained. By comparing the results from VORLAX to a wind tunnel study, I determined that the poor lateral directional stability and control coupling issues were foreseeable in the initial design.
ContributorsObrien, Kevin (Author) / Takahashi, Timothy (Thesis director) / Nullmeyer, Robert (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2021-12
Description
As the push to develop ever more efficient aircraft increases, the use of lightweight composite materials to meet this push has increased. Traditional aircraft structural component sizing has revolved around the tensile yield strength of materials. Since composite materials excel in tensile strength, these traditional sizing tools provide overly optimistic weight reduction predictions. Furthermore, composite materials, in general, are weak under compression and shear. Thus, proper structural sizing yields heavier-than-expected designs. Nevertheless, a wing using thin, lightweight composites in the primary load-bearing components significantly impacts its static aeroelastic properties. These thin structures have a decreased flexural rigidity, making them more susceptible to bending. The bending of swept wings decreases the design wing twist and dihedral angle, potentially impacting the aerodynamic performance and the lateral stability and control, respectively. This work aims to determine what, if any, are the effects of excessive static aeroelastic properties on the aerodynamic performance of an aircraft. Does the perceived gain in the theoretical reduction in structural weight outweigh the potential reduction in aerodynamic performance?
ContributorsWebb, Benjamin David (Author) / Takahashi, Timothy (Thesis advisor) / Herrmann, Marcus (Committee member) / Perez, Ruben (Committee member) / Arizona State University (Publisher)
Created2022
Description
The process of designing any real world blunt leading-edge wing is tedious andinvolves hundreds, if not thousands, of design iterations to narrow down a single design.
Add in the complexities of supersonic flow and the challenge increases exponentially.
One possible, and often common, pathway for this design is to jump straight into detailed
volume grid computational fluid dynamics (CFD), in which the physics of supersonic
flow are modeled directly but at a high computational cost and thus an incredibly long
design process. Classical aerodynamics experts have published work describing a process
which can be followed which might bypass the need for detailed CFD altogether.
This work outlines how successfully a simple vortex lattice panel method CFDcode can be used in the design process for a Mach 1.3 cruise speed airline wing concept.
Specifically, the success of the wing design is measured in its ability to operate subcritically (i.e. free of shock waves) even in a free stream flow which is faster than the
speed of sound. By using a modified version of Simple Sweep Theory, design goals are
described almost entirely based on defined critical pressure coefficients and critical Mach
numbers. The marks of a well-designed wing are discussed in depth and how these traits
will naturally lend themselves to a well-suited supersonic wing.
Unfortunately, inconsistencies with the published work are revealed by detailedCFD validation runs to be extensive and large in magnitude. These inconsistencies likely
have roots in several concepts related to supersonic compressible flow which are
explored in detail. The conclusion is made that the theory referenced in this work by the
classical aerodynamicists is incorrect and/or incomplete. The true explanation for the
perplexing shock wave phenomenon observed certainly lies in some convolution of the
factors discussed in this thesis. Much work can still be performed in the way of creating
an empirical model for shock wave formation across a highly swept wing with blunt
leading-edge airfoils.
Add in the complexities of supersonic flow and the challenge increases exponentially.
One possible, and often common, pathway for this design is to jump straight into detailed
volume grid computational fluid dynamics (CFD), in which the physics of supersonic
flow are modeled directly but at a high computational cost and thus an incredibly long
design process. Classical aerodynamics experts have published work describing a process
which can be followed which might bypass the need for detailed CFD altogether.
This work outlines how successfully a simple vortex lattice panel method CFDcode can be used in the design process for a Mach 1.3 cruise speed airline wing concept.
Specifically, the success of the wing design is measured in its ability to operate subcritically (i.e. free of shock waves) even in a free stream flow which is faster than the
speed of sound. By using a modified version of Simple Sweep Theory, design goals are
described almost entirely based on defined critical pressure coefficients and critical Mach
numbers. The marks of a well-designed wing are discussed in depth and how these traits
will naturally lend themselves to a well-suited supersonic wing.
Unfortunately, inconsistencies with the published work are revealed by detailedCFD validation runs to be extensive and large in magnitude. These inconsistencies likely
have roots in several concepts related to supersonic compressible flow which are
explored in detail. The conclusion is made that the theory referenced in this work by the
classical aerodynamicists is incorrect and/or incomplete. The true explanation for the
perplexing shock wave phenomenon observed certainly lies in some convolution of the
factors discussed in this thesis. Much work can still be performed in the way of creating
an empirical model for shock wave formation across a highly swept wing with blunt
leading-edge airfoils.
ContributorsKurus, Noah John (Author) / Takahashi, Timothy (Thesis advisor) / Benson, David (Committee member) / Niemczyk, Mary (Committee member) / Arizona State University (Publisher)
Created2020
Description
In a society that is becoming more technologically driven, it is important to have people to design, test, and build new things in order for society to progress. This is oftentimes the role of an engineer. However, engineering school is not easy, and engineering students don’t always make it all the way through school to get an engineering job. This thesis is an in-depth analysis of an engineering student’s path - from choosing engineering as a major to ultimately transitioning into a full-time engineering job. It will do this by covering (1) what engineering is and what career opportunities exist within the discipline, (2) common pitfalls that students may encounter while going through engineering school, (3) how to get an engineering job in industry, and (4) how to appropriately transition into an industry job using the skills from engineering school. While talking about what engineering is and what career opportunities exist, this thesis will discuss engineering as a profession, the ABET accreditation board, and careers in industry vs academia. As part of common pitfalls that engineering students face, this thesis will discuss tenure track, theory vs reality, cooperative learning, and misconceptions about engineering. In order to talk about how to get an industry job, this thesis will discuss the impact of grades, relevant experience, communication, personal branding, and industry options. Finally, while talking about effectively transitioning into industry, this thesis will discuss understanding the skills gained from engineering school, the different roles in industry, and how to appropriately apply those skills. Ultimately this thesis aims to be a resource for students interested in engineering so that they can understand how to successfully make it through school and move into the work force effectively.
ContributorsJordan, Arminta Claire (Author) / Takahashi, Timothy (Thesis director) / Zhu, Haolin (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The goal of this thesis project was to build an understanding of supersonic projectile dynamics through the creation of a trajectory model that incorporates several different aerodynamic concepts and builds a criteria for the stability of a projectile. This was done iteratively where the model was built from a foundation of kinematics with various aerodynamic principles being added incrementally. The primary aerodynamic principle that influenced the trajectory of the projectile was in the coefficient of drag. The drag coefficient was split into three primary components: the form drag, skin friction drag, and base pressure drag. These together made up the core of the model, additional complexity served to increase the accuracy of the model and generalize to different projectile profiles.
ContributorsBlair, Martin (Co-author) / Armenta, Francisco (Co-author) / Takahashi, Timothy (Thesis director) / Herrmann, Marcus (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05