Current Search: Noise control (x)
View All Items
(1 - 4 of 4)
- Title
- Suppression of Turbofan and Turbojet Engine Generated Noise.
- Creator
-
Master, Harry D., Ventre, Gerald G., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; Every advance in the transformation of heat energy into mechanical energy has involved a noise problem, and in general it increases with the power production. The jet airplane is a good example: the large-scale turbulence of the exhaust gases in the jet forms an unusually intense source of sound the control of which is quite difficult. The additionally generated fan noises add characteristic fan tones which are particularly...
Show moreFlorida Technological University College of Engineering Thesis; Every advance in the transformation of heat energy into mechanical energy has involved a noise problem, and in general it increases with the power production. The jet airplane is a good example: the large-scale turbulence of the exhaust gases in the jet forms an unusually intense source of sound the control of which is quite difficult. The additionally generated fan noises add characteristic fan tones which are particularly noticeable on landing approaches. the human ear is the vulnerable receiver of these noises, and the problem becomes one of deciding how much jet engine noise reduction is required for the comfort or safety of the receiver, and then to devise ways to achieve it.
Show less - Date Issued
- 1972
- Identifier
- CFR0011987, ucf:53093
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011987
- Title
- An Industrial Audiological Approach to Design and Construction of Enclosures for Control of Noise.
- Creator
-
Smart, Dale G., Mullin, Thomas A., Social Sciences
- Abstract / Description
-
Florida Technological University College of Social Sciences Thesis
- Date Issued
- 1975
- Identifier
- CFR0011993, ucf:53084
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011993
- Title
- Reduction of Lunchroom Noise and Other Behavior Using Feedback and Group Contingent Reinforcement.
- Creator
-
LaRowe, Lottie N., Tucker, Richard, Social Sciences
- Abstract / Description
-
Florida Technological University College of Social Sciences Thesis; Reduction of noise levels in an elementary school lunchroom was examined as a function of feedback and feedback plus reinforcement using group contingency procedures. Feedback consisted of signals from a traffic light with green indicating acceptable levels, yellow indicating slightly higher levels and red indicating unacceptable levels. Other behaviors, running, hitting, pushing and kicking, were measured incidentally....
Show moreFlorida Technological University College of Social Sciences Thesis; Reduction of noise levels in an elementary school lunchroom was examined as a function of feedback and feedback plus reinforcement using group contingency procedures. Feedback consisted of signals from a traffic light with green indicating acceptable levels, yellow indicating slightly higher levels and red indicating unacceptable levels. Other behaviors, running, hitting, pushing and kicking, were measured incidentally. Results indicate that feedback plus reinforcement was effective in reducing noise levels. Feedback alone was also effective, but to a lesser degree. No response - response relationship was found to exist between noise level and the other behaviors.
Show less - Date Issued
- 1978
- Identifier
- CFR0004324, ucf:52988
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0004324
- Title
- APPLICATION OF ABSORPTIVE TREATMENTS ON TRAFFIC NOISE BARRIERS IN FLORIDA.
- Creator
-
Chua, Chin Boon, Wayson, Roger, University of Central Florida
- Abstract / Description
-
In this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier...
Show moreIn this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier insertion loss. The best fit equation model was then used to test against measured/model result and TNM prediction results for its validity. Absorptive materials were also studied such that 3 top of them were selected and recommended for Florida highway barrier use. It was found that the top three absorptive treatments for use on Florida highway barriers have been determined to be cementitous material, metal wool and glass fiber. These materials can be used to reduce the sound reflections for single and parallel barriers. The developed best fit equation model from this research is Deg = -2.17NRC - CW0.42 + 1.97eln(BH) + RH0.29 + DBB0.27; the prediction results give moderately high R2 value of 0.55 if compared to the results from database. Prediction results from best fit equation model was also found to be consistent with the results from the measure/modeled results, providing further proof of the validity of the model. However, if compared results from equation model, TNM and measured/model (measured and model compared results using ANSI method), TNM was shown to provide higher insertion loss degradation. It was found that the most effective placement of absorptive material was the pattern which covers the barrier from the bottom up; it was also found that only about 60% from the bottom of the barrier area requires covering with high NRC absorptive treatment (NRC greater than 0.8) without sacrificing insertion loss. Also, if the barrier area near the top includes an easily obtainable NRC value of 0.4, only 40% to 50% of the bottom barrier needs absorptive treatment with a higher, more expensive NRC rating. These findings can substantially reduce the cost of conventional absorptive barrier which have full coverage of high NRC absorptive treatment. This research has begun important improvements in noise barrier design, additional work can be continued to further verify all the findings in this thesis such that easier and better equation model can be developed to calculate insertion loss degradation and cheaper absorptive barrier with less absorptive material usage can be built.
Show less - Date Issued
- 2004
- Identifier
- CFE0000008, ucf:46127
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000008
