Prediction and Reduction of Alarm Sound Propagation Through Escape Stairways

2021 ◽  
Author(s):  
Jeong-Ho Jeong
2020 ◽  
Vol 20 (4) ◽  
pp. 145-152
Author(s):  
Jeong-ho Jeong

Gas extinguishing systems are used for fire protection in server rooms and data centers. In the fire safety standards (NFSC 106, 107) of gas extinguishing systems (carbon dioxide, halon, and clean agent extinguishing system), sound alarm devices are installed in each protected area to provide an effective warning to personnel in the protected area or areas with objects to be protected. By measuring the noise level generated in a small server room, it was found that more than 70 dB of noise was generated. Therefore, to effectively transmit alarm sound to workers in all areas within the protection area, such as a server room, an acoustic alarm device must be designed and installed so that an alarm sound is transmitted at a level of 15 dB or higher than the noise level generated by equipment installed in the facility. As a result of predicting the alarm sound through the room acoustic simulation for a small server room equipped with an acoustic alarm system in a cabinet-type gas extinguishing system, it was found that it was insufficient in effectively delivering an alarm sound to the entire protection area. To effectively transmit an alarm sound inside the protection area where a gas extinguishing system is installed, the output of the alarm device needs to be increased and the room acoustic parameters should be predicted in advance using room acoustic prediction techniques and actively adjusting the acoustics according to the noise generated inside the protection area. Additionally, the distance between alarm devices needs to be shortened to deliver sufficient alarm volume throughout the protection area, and it is necessary to establish specific standards for this.


2017 ◽  
Vol 13 (1) ◽  
pp. 4522-4534
Author(s):  
Armando Tomás Canero

This paper presents sound propagation based on a transverse wave model which does not collide with the interpretation of physical events based on the longitudinal wave model, but responds to the correspondence principle and allows interpreting a significant number of scientific experiments that do not follow the longitudinal wave model. Among the problems that are solved are: the interpretation of the location of nodes and antinodes in a Kundt tube of classical mechanics, the traslation of phonons in the vacuum interparticle of quantum mechanics and gravitational waves in relativistic mechanics.


AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 768-773 ◽  
Author(s):  
Yusuf Ozyoruk ◽  
Lyle N. Long

1989 ◽  
Author(s):  
EDMOND LO ◽  
R. FERGUSON ◽  
MICHAEL FRISH ◽  
PETERE. NEBOLSINE
Keyword(s):  

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