Yan, Rongxin; Beijing Insititute of Spacecraft Enviroment Engineering; China
Li, W.; Beijing Institute of Spacecraft Environment Engineering; China
Sun, W.; Beijing Institute of Spacecraft Environment Engineering; China
Yan, R.; Beijing Institute of Spacecraft Environment Engineering; China
Session: Aerospace 2
Time: 14:30 - 14:50
In this paper, the mechanism of air gas leaking out from spacecraft into vacuum producing sound, sound transmitting in cabin air and sound signal detecting will be analyzed. An equation of the sound power, leak size and air gas pressure in the spacecraft is got, and the relationship between leak sound pressure and receiving direction and distance has been studied. The center frequency in millimeter diameter leak is more than 20 kHz. The simulation equipment of air leaking out from spacecraft to space has been set up and the experiment of different size leak and testing distance and direction has been done. The sound pressure is in direct proportion to the cosine of the angle of leak to sensor. The portable ultrasonic leak detector has been developed, whose minimal leak rate is 10-1Pam3s-1. The leak detector consists of the sensor, mainframe, structure, preamplifier, DSP, display and key-press circuit, power supply and batteries. The accuracy of distance for locating the leaks is less than 20 mm, the mass is 1.2kg, and the electric power is less than 2.2W.