Acoustics and gas discharges: applications to loudspeakers

Abstract

The main purpose of this review is to expound results related to the production of ordinary sound waves by electrical discharges. Work on different kinds of discharge especially glow, arc and 'true' corona are presented and classified according to the relative importance of different acoustic source terms, namely the 'heat' term and the 'force' term. Related fields such as lightning and thunder are also dealt with. Different applications are presented but emphasis is given to 'plasma' loudspeakers. Fields in which knowledge is not well established are also outlined.

Stable sound wave generation in weakly ionized air medium

“…Это открывает возможности для проектирования без мембранных акустических систем [3][4][5]. Суть рабо-ты любого громкоговорителя -это преобразование электрической энергии в колебания давления воздуха.…”

Phenomena in gases and plasmas with negative ions

“…Генерация и усиление звука. Явление усиления звуковых волн (акустическая не-устойчивость) в плазме газового разряда неодно-кратно наблюдалось в виде самопроизвольного раз-вития акустических колебаний в таких средах [68,87]. Имеются также измерения коэффициента уси-ления искусственно созданных звуковых волн в по-ложительном столбе тлеющего разряда [88][89][90] Ситуация меняется в электроотрицательном газе при наличии прилипания электронов, скорость кото-рого быстро увеличивается с ростом E/N.…”

Propagation characteristics of audible noise generated by single corona source under positive DC voltage

“…Therefore, the corona-generated AN has been an ongoing topic of investigation by both physicists and electrical engineers in the past few decades. [4][5][6][7][8][9] The corona discharge on the on the conductors of transmission lines is usually caused by defects or contaminations which are the main corona sources due to the high electric filed on their surface. The corona sources may spread randomly along transmission lines and the AN from transmission line is the comprehensive effect from all the corona sources.…”

“…4 The theory of acoustic wave generation by the gas discharge was first proposed by Ingard in 1966. 10 In his work, he investigated the acoustic wave generation and amplification in weakly ionized gases (glow discharges).…”