Advances in Acoustics and Vibration / 2012 / Article / Tab 4

Research Article

The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

Table 4

System acoustic calculation at the tunnel and atmospheric side.

63 Hz125 Hz250 Hz500 Hz1 KHz2 KHz4 KHz8 KHz

Tunnel side
 Fan LW123120130130127121120114
 System losses00000000
 Room effect−3−5−7−9−10−11−11−12
 Attenuator insertion loss−16−32−45−50−50−50−38−27
 Resultant LwA (85 dBA spec)8110483787167607175

Atmospheric side
 Fan LW123120130130127121120114
 System losses−2−3−4−5−5−5−6−6
 Atmos effect−14−14−14−13−13−13−13−13
 Attenuator insertion loss−8−20−33−40−50−48−25−15
 Resultant (85 dBA spec)82.39983797259557680