Matching Items (6)
Filtering by

Clear all filters

Description
This thesis seeks to further explore off-design point operation of gas turbines and to examine the capabilities of GasTurb 12 as a tool for off-design analysis. It is a continuation of previous thesis work which initially explored the capabilities of GasTurb 12. The research is conducted in order to: 1)

This thesis seeks to further explore off-design point operation of gas turbines and to examine the capabilities of GasTurb 12 as a tool for off-design analysis. It is a continuation of previous thesis work which initially explored the capabilities of GasTurb 12. The research is conducted in order to: 1) validate GasTurb 12 and, 2) predict off-design performance of the Garrett GTCP85-98D located at the Arizona State University Tempe campus. GasTurb 12 is validated as an off-design point tool by using the program to predict performance of an LM2500+ marine gas turbine. Haglind and Elmegaard (2009) published a paper detailing a second off-design point method and it includes the manufacturer's off-design point data for the LM2500+. GasTurb 12 is used to predict off-design point performance of the LM2500+ and compared to the manufacturer's data. The GasTurb 12 predictions show good correlation. Garrett has published specification data for the GTCP85-98D. This specification data is analyzed to determine the design point and to comment on off-design trends. Arizona State University GTCP85-98D off-design experimental data is evaluated. Trends presented in the data are commented on and explained. The trends match the expected behavior demonstrated in the specification data for the same gas turbine system. It was originally intended that a model of the GTCP85-98D be constructed in GasTurb 12 and used to predict off-design performance. The prediction would be compared to collected experimental data. This is not possible because the free version of GasTurb 12 used in this research does not have a module to model a single spool turboshaft. This module needs to be purchased for this analysis.
ContributorsMartinjako, Jeremy (Author) / Trimble, Steve (Thesis advisor) / Dahm, Werner (Committee member) / Middleton, James (Committee member) / Arizona State University (Publisher)
Created2014
151175-Thumbnail Image.png
Description
The primary purpose of this study is to examine the effect of knowledge for teaching mathematics and teaching practice on student mathematics achievement growth. Thirty two teachers and 299 fourth grade students in three elementary schools from one school district in urban area participated in the study. Most of them

The primary purpose of this study is to examine the effect of knowledge for teaching mathematics and teaching practice on student mathematics achievement growth. Thirty two teachers and 299 fourth grade students in three elementary schools from one school district in urban area participated in the study. Most of them are Hispanic in origin and about forty percent is English Language Learners (ELLs). The two level Hierarchical Linear Model (HLM) was used to investigate repeated measures of teaching practice measured by Classroom Assessment Scoring System (CLASS) instrument. Also, linear regression and a multiple regression to examine the relationship between teacher knowledge measured by Learning for Mathematics Teaching (LMT) and Developing Mathematical Ideas (DMI) items and teaching practice were employed. In addition, a three level HLM was employed to analyze repeated measures of student mathematics achievement measured by Arizona Assessment Consortium (AzAC) instruments. Results showed that overall teaching practice did not change weekly although teachers' emotional support for their students improved by week. Furthermore, a statistically significant relationship between teacher knowledge and teaching practice was not found. In terms of student learning, ELLs have significantly lower initial status in mathematics achievement than non-ELLs, as were growth rates for these two groups. Lastly, teaching practice significantly predicted students' monthly mathematics achievement growth but teacher knowledge did not. The findings suggest that school systems and education policy makers need to provide teachers with the chance to reflect on their teaching and change it within themselves in order to better support student mathematics learning.
ContributorsKim, Seong Hee (Author) / Sloane, Finbarr (Thesis advisor) / Middleton, James (Committee member) / Flores, Alfinio (Committee member) / Arizona State University (Publisher)
Created2012
134375-Thumbnail Image.png
Description
To determine the effects of exhaust heat recovery systems on small engines, an experiment was performed to measure the power losses of an engine with restricted exhaust flow. In cooperation with ASU's SAE Formula race team, a water brake dynamometer was refurbished and connected to the 2017 racecar engine. The

To determine the effects of exhaust heat recovery systems on small engines, an experiment was performed to measure the power losses of an engine with restricted exhaust flow. In cooperation with ASU's SAE Formula race team, a water brake dynamometer was refurbished and connected to the 2017 racecar engine. The engine was mounted with a diffuser disc exhaust to restrict flow, and a pressure sensor was installed in the O2 port to measure pressure under different restrictions. During testing, problems with the equipment prevented suitable from being generated. Using failure root cause analysis, the failure modes were identified and plans were made to resolve those issues. While no useful data was generated, the project successfully rebuilt a dynamometer for students to use for future engine research.
ContributorsRoss, Zachary David (Author) / Middleton, James (Thesis director) / Steele, Bruce (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description

This study experimentally investigated a selected methodology of mechanical torque testing of 3D printed gears. The motivation for pursuing this topic of research stemmed from a previous experience of one of the team members that propelled inspiration to quantify how different variables associated with 3D printing affect the structural integrity

This study experimentally investigated a selected methodology of mechanical torque testing of 3D printed gears. The motivation for pursuing this topic of research stemmed from a previous experience of one of the team members that propelled inspiration to quantify how different variables associated with 3D printing affect the structural integrity of the resulting piece. With this goal in mind, the team set forward with creating an experimental set-up and the construction of a test rig. However, due to restrictions in time and other unforeseen circumstances, this thesis underwent a change in scope. The new scope focused solely on determining if the selected methodology of mechanical torque testing was valid. Following the securement of parts and construction of a test rig, the team was able to conduct mechanical testing. This testing was done multiple times on an identically printed gear. The data collected showed results similar to a stress-strain curve when the torque was plotted against the angle of twist. In the resulting graph, the point of plastic deformation is clearly visible and the maximum torque the gear could withstand is clearly identifiable. Additionally, across the tests conducted, the results show high similarity in results. From this, it is possible to conclude that if the tests were repeated multiple times the maximum possible torque could be found. From that maximum possible torque, the mechanical strength of the tested gear could be identified.

ContributorsGarcia, Andres (Author) / Parekh, Mohan (Co-author) / Middleton, James (Thesis director) / Murthy, Raghavendra (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description

This study experimentally investigated a selected methodology of mechanical torque testing of 3D printed gears. The motivation for pursuing this topic of research stemmed from a previous experience of one of the team members that propelled inspiration to quantify how different variables associated with 3D printing affect the structural integrity

This study experimentally investigated a selected methodology of mechanical torque testing of 3D printed gears. The motivation for pursuing this topic of research stemmed from a previous experience of one of the team members that propelled inspiration to quantify how different variables associated with 3D printing affect the structural integrity of the resulting piece. With this goal in mind, the team set forward with creating an experimental set-up and the construction of a test rig. However, due to restrictions in time and other unforeseen circumstances, this thesis underwent a change in scope. The new scope focused solely on determining if the selected methodology of mechanical torque testing was valid. Following the securement of parts and construction of a test rig, the team was able to conduct mechanical testing. This testing was done multiple times on an identically printed gear. The data collected showed results similar to a stress-strain curve when the torque was plotted against the angle of twist. In the resulting graph, the point of plastic deformation is clearly visible and the maximum torque the gear could withstand is clearly identifiable. Additionally, across the tests conducted, the results show high similarity in results. From this, it is possible to conclude that if the tests were repeated multiple times the maximum possible torque could be found. From that maximum possible torque, the mechanical strength of the tested gear could be identified.

ContributorsParekh, Mohan (Author) / Garcia, Andres (Co-author) / Middleton, James (Thesis director) / Murthy, Raghavendra (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05
Description

This study investigates whether an experience as a novice can help alleviate expert blindness in Arizona State University faculty. Expert blindness, also known as the expert blind spot, is a phenomenon in which an expert in any subject finds it difficult to teach because they are so advanced at it.

This study investigates whether an experience as a novice can help alleviate expert blindness in Arizona State University faculty. Expert blindness, also known as the expert blind spot, is a phenomenon in which an expert in any subject finds it difficult to teach because they are so advanced at it. Many faculty have taught the same subject for so long that certain things that are difficult for beginners in their courses are trivial for the expert. In this experiment, ASU faculty were given five weeks of instruction to learn to solve the Rubik’s Cube in five minutes or less. Before and after the five-week experience, the participants took the Interpersonal Reactivity Index assessment, which measures empathy. Throughout the Rubik’s Cube challenge, the faculty were also asked discussion questions and invited to participate in informal interviews. The study finds a significant increase in the “empathic concern” of the participants after the experience, with a sample size of five participants. The qualitative interview data confirms the survey data, and the main sentiments of the professors after going through the experience were distilled into four main themes: (a) patience and reflection; (b) individualized approaches; (c) trying, failing, and improving; (d) knowing what and when to explain. An effective teacher who is aware of their tendency towards expert blindness should be aware of these four themes and strive to include them in their own teaching. The study recommends that universities and companies should have “beginner experiences” at regular intervals to remind experts what it is like to be a beginner again. These experiences not only mitigate the expert blind spot but promote lifelong learning and an active brain.

ContributorsLarson, Paul (Author) / Middleton, James (Thesis director) / Hines, Taylor (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-05