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Description
Dimensional Metrology is the branch of science that determines length, angular, and geometric relationships within manufactured parts and compares them with required tolerances. The measurements can be made using either manual methods or sampled coordinate metrology (Coordinate measuring machines). Manual measurement methods have been in practice for a long time and are well accepted in the industry, but are slow for the present day manufacturing. On the other hand CMMs are relatively fast, but these methods are not well established yet. The major problem that needs to be addressed is the type of feature fitting algorithm used for evaluating tolerances. In a CMM the use of different feature fitting algorithms on a feature gives different values, and there is no standard that describes the type of feature fitting algorithm to be used for a specific tolerance. Our research is focused on identifying the feature fitting algorithm that is best used for each type of tolerance. Each algorithm is identified as the one to best represent the interpretation of geometric control as defined by the ASME Y14.5 standard and on the manual methods used for the measurement of a specific tolerance type. Using these algorithms normative procedures for CMMs are proposed for verifying tolerances. The proposed normative procedures are implemented as software. Then the procedures are verified by comparing the results from software with that of manual measurements.
To aid this research a library of feature fitting algorithms is developed in parallel. The library consists of least squares, Chebyshev and one sided fits applied on the features of line, plane, circle and cylinder. The proposed normative procedures are useful for evaluating tolerances in CMMs. The results evaluated will be in accordance to the standard. The ambiguity in choosing the algorithms is prevented. The software developed can be used in quality control for inspection purposes.
To aid this research a library of feature fitting algorithms is developed in parallel. The library consists of least squares, Chebyshev and one sided fits applied on the features of line, plane, circle and cylinder. The proposed normative procedures are useful for evaluating tolerances in CMMs. The results evaluated will be in accordance to the standard. The ambiguity in choosing the algorithms is prevented. The software developed can be used in quality control for inspection purposes.
ContributorsVemulapalli, Prabath (Author) / Shah, Jami J. (Thesis advisor) / Davidson, Joseph K. (Committee member) / Takahashi, Timothy (Committee member) / Arizona State University (Publisher)
Created2014
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
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