Effects of Pipe Length under Water Surface and Water Pressure on Tonal Quality of Water Musical Instrument

摘要

The water musical instrument which consists of many resonance tubes, many nozzles and water surface, can play a variety of music through computer-control or the manual playing of a piano. The intrinsic peaceful sound of this instrument depends on the air-bubbles formed by the impact of the water droplet on the water surface. Thus the control of the air-bubbles is the key to the tonal quality. Because the pipe length sunk in water determines the shapes of the air-bubbles, it could control the quality of the sound source. Moreover, the water pressure exerted on a nozzle can change the formation process of the bubble. Therefore, the effects of both the pipe length sunken under the water and the water pressure on the generated sound, and the process of the formation and the collapse of the air bubbles have been studied. The experimental results show that the radiated tone from the exit of the resonance pipe is produced by the vibration of air-bubbles and by the resonance of air-column in the pipe, and they also show that the water pressure should be kept below 9.8kPa for the suited design of the water musical instrument.