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Development of the Carbon Nanotube Thermoacoustic Loudspeaker.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Development of the Carbon Nanotube Thermoacoustic Loudspeaker./
作者:	Bouman, Troy M.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	123 p.
附註:	Source: Dissertations Abstracts International, Volume: 82-12, Section: B.
Contained By:	Dissertations Abstracts International82-12B.
標題:	Acoustics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28418455
ISBN:	9798738648830

Development of the Carbon Nanotube Thermoacoustic Loudspeaker.
Bouman, Troy M.

Development of the Carbon Nanotube Thermoacoustic Loudspeaker. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 123 p.

Source: Dissertations Abstracts International, Volume: 82-12, Section: B.

Thesis (Ph.D.)--Michigan Technological University, 2021.

This item must not be sold to any third party vendors.

Traditional speakers make sound by attaching a coil to a cone and moving that coil back and forth in a magnetic field (aka moving coil loudspeakers). The physics behind how to generate sound via this velocity boundary condition has largely been unchanged for over a hundred years. Interestingly, around the time moving coil loudspeakers were first investigated the idea of using heat to generate sound was also known. These thermoacoustic speakers heat and cool a thin material at acoustic frequencies to generate the pressure wave (i.e. they use a thermal boundary condition). Unfortunately, when the thermoacoustic principle was initially discovered there was no material with the right properties to heat and cool fast enough. Carbon nanotube (CNT) loudspeakers first generated sound early in the 21st century. At that time there were many questions unanswered about their place in the sound generation toolbox of an engineer. The main goal of this dissertation was to continue the development of the CNT loudspeaker with focus on practical usage for an acoustic engineer. Prior to 2014, when this effort began, most of the published development work was from material scientists with objective acoustic performance data presented that was not useful beyond the scope of that particular publication. For example, low sound pressure levels in the nearfield at low power inputs was a common metric. Therefore, this effort had three main objectives with emphasis placed on acquiring data at levels and in nomenclature that would be useful to acoustic engineers so they could bring the technology to market, if adequate:i) Investigation into the true power efficiency of CNT loudspeakers, ii) Investigation into alternative methods to linearize the pressure response ofCNT loudspeakers, iii) Investigation into the sound quality of CNT loudspeakers.Overall, it was found that CNT loudspeakers are approximately four orders of magnitude less power efficient than traditional moving coil loudspeakers. The non-linear pressure output of the CNT loudspeakers can be linearized with a variety of drive signal processing methods, but the selection of which method to use depends on a variety of factors (e.g. amplification architecture available). In general, all methods studied are on the same order of magnitude power efficiency, but the direct current offset and amplitude modulation drive signal processing methods are superior in terms of sound quality.

ISBN: 9798738648830Subjects--Topical Terms:

879105
Acoustics.
Subjects--Index Terms:

Acoustics

Development of the Carbon Nanotube Thermoacoustic Loudspeaker.
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300 $a 123 p.
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520 $a Traditional speakers make sound by attaching a coil to a cone and moving that coil back and forth in a magnetic field (aka moving coil loudspeakers). The physics behind how to generate sound via this velocity boundary condition has largely been unchanged for over a hundred years. Interestingly, around the time moving coil loudspeakers were first investigated the idea of using heat to generate sound was also known. These thermoacoustic speakers heat and cool a thin material at acoustic frequencies to generate the pressure wave (i.e. they use a thermal boundary condition). Unfortunately, when the thermoacoustic principle was initially discovered there was no material with the right properties to heat and cool fast enough. Carbon nanotube (CNT) loudspeakers first generated sound early in the 21st century. At that time there were many questions unanswered about their place in the sound generation toolbox of an engineer. The main goal of this dissertation was to continue the development of the CNT loudspeaker with focus on practical usage for an acoustic engineer. Prior to 2014, when this effort began, most of the published development work was from material scientists with objective acoustic performance data presented that was not useful beyond the scope of that particular publication. For example, low sound pressure levels in the nearfield at low power inputs was a common metric. Therefore, this effort had three main objectives with emphasis placed on acquiring data at levels and in nomenclature that would be useful to acoustic engineers so they could bring the technology to market, if adequate:i) Investigation into the true power efficiency of CNT loudspeakers, ii) Investigation into alternative methods to linearize the pressure response ofCNT loudspeakers, iii) Investigation into the sound quality of CNT loudspeakers.Overall, it was found that CNT loudspeakers are approximately four orders of magnitude less power efficient than traditional moving coil loudspeakers. The non-linear pressure output of the CNT loudspeakers can be linearized with a variety of drive signal processing methods, but the selection of which method to use depends on a variety of factors (e.g. amplification architecture available). In general, all methods studied are on the same order of magnitude power efficiency, but the direct current offset and amplitude modulation drive signal processing methods are superior in terms of sound quality.
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