Sound Suppression System

Sound Suppression Test Unleashes a Flood

A roar resounded from one of the Space Shuttle launch pads May 7 as 350,000 gallons of water rushed across the Mobile Launcher Platform (MLP).The water system is designed to protect the Shuttle and its payloads from any damage that may occur from acoustical energy reflected from the Mobile Launcher Platform (MLP) during launch. The water is released seconds before ignition of the orbiter's three main engines and twin Solid Rocket Boosters (SRB), then flows through parallel 7-foot-diameter pipes to the Pad.

The system includes a 290-foot-high water tank filled with 300,000 gallons of water, and it empties in 41 seconds during a launch. Water pours from 16 nozzles on top of the flame deflectors and from outlets in the Shuttle main engine exhaust hole in the MLP at main engine ignition, which occurs approximately 7 seconds before liftoff.

The system was first installed at the pad when reflective energy from the top of the Mobile Launch Platform was causing minor damage to thermal curtains on the SRBs and putting stress on the wings. After adding the system, the sound pressure was reduced by half.

Source : Sound Suppression Test Unleashes a Flood

On the right side of this picture, you can see the water tower located near by the Launch Pad.

Air bubbles absorb the sound. The bubbles soak up the sound by getting hot. The wave of the sound squashes the air bubbles. The German U-Boat used the rubber tile with bubbles which absorb the wave from the allied sonar.

Anechoic Tile

This picture shows the Vortex Cannon fires the sound ring in  the air. The water curtain is the same as the Water Sound Suppression of NASA.

In the slow motion, you can see how the pulse of air hits the water and lose energy.The power of the bubble which used by NASA engineers to absorb the phenomenal sound energy.