A new experimental device for measuring sonic boomtransmission into buildings

摘要

Reduction of sonic booms is one of the most important environmental challenges in overlandrnsupersonic flights. Since sonic booms differ from other transportation noise in the sense that theyrnare very strong shock waves with large acoustic energy at very low frequencies, specialrnevaluation metrics and acceptability standards are necessary. Also, for practical evaluation ofrnsonic booms in everyday life, sonic booms under both indoor and outdoor conditions need to berninvestigated. With this in mind, a new sonic boom simulator is under development by JapanrnAerospace Exploration Agency (JAXA). After investigating synthesis methods of sonic boomsrnby using a simple sonic boom simulator with headphones in the first phase, a new device forrnsimulating and investigating indoor sonic booms has been developed in the second phase and isrnreported in this study. In this device, synthetic sonic booms are played back throughrnloudspeakers, and the sonic boom signatures before and after transmitting architectural materials,rnas well as vibrations of the materials, are measured. The device developed in this study will bernintegrated in a new sonic boom simulator, which is currently under development in the finalrnphase, to simulate sonic booms in indoor spaces. This simulator will be used for psychoacousticrnexperiments with test subjects to investigate the effects and acceptability of sonic booms bothrnindoors and outdoors.