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Commonmark migration

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edited Jun 17, 2020 at 8:54

The mechanism seems to be related to the bubbles in water rather than the water itself:

Bubbles are excellent at absorbing the sound. They absorb the acoustic energy and as a consequence of which get heated up. NASA exploited this and sprayed water molecules in the air surrounding the Mobile Launcher Platform. This reduced the sound from the firing of the rockets by almost a half! (3 dB)

Further reading in this study:

There are two primary types of water-based acoustic suppression system; a below-deck system where water is injected into the exhaust plume with the aim of reducing far-field noise by more rapid dispersion of the rocket exhaust [12] or an above-deck system where water is injected around the pad.

Norum [16] carried out an extensive investigation into the suppression of dominant noise sources in both subsonic and supersonic jets, and the results were able to be extrapolated to full-scale engines. This work showed that within the jet plume, water injection clearly disrupts the shock noise sources, leading to a reduction in SAN.

Water injection into the flame trench:

For the water injection, critical parameters were the injection angle, the injection water flow rate and the location of the water injection point. Their results indicated that to achieve any significant noise reduction, the quantity of water injected must be at least three times the jet flow rate.

and more reading.

The mechanism seems to be related to the bubbles in water rather than the water itself:

Bubbles are excellent at absorbing the sound. They absorb the acoustic energy and as a consequence of which get heated up. NASA exploited this and sprayed water molecules in the air surrounding the Mobile Launcher Platform. This reduced the sound from the firing of the rockets by almost a half! (3 dB)

Further reading in this study:

There are two primary types of water-based acoustic suppression system; a below-deck system where water is injected into the exhaust plume with the aim of reducing far-field noise by more rapid dispersion of the rocket exhaust [12] or an above-deck system where water is injected around the pad.

Norum [16] carried out an extensive investigation into the suppression of dominant noise sources in both subsonic and supersonic jets, and the results were able to be extrapolated to full-scale engines. This work showed that within the jet plume, water injection clearly disrupts the shock noise sources, leading to a reduction in SAN.

Water injection into the flame trench:

For the water injection, critical parameters were the injection angle, the injection water flow rate and the location of the water injection point. Their results indicated that to achieve any significant noise reduction, the quantity of water injected must be at least three times the jet flow rate.

and more reading.

The mechanism seems to be related to the bubbles in water rather than the water itself:

Bubbles are excellent at absorbing the sound. They absorb the acoustic energy and as a consequence of which get heated up. NASA exploited this and sprayed water molecules in the air surrounding the Mobile Launcher Platform. This reduced the sound from the firing of the rockets by almost a half! (3 dB)

Further reading in this study:

There are two primary types of water-based acoustic suppression system; a below-deck system where water is injected into the exhaust plume with the aim of reducing far-field noise by more rapid dispersion of the rocket exhaust [12] or an above-deck system where water is injected around the pad.

Norum [16] carried out an extensive investigation into the suppression of dominant noise sources in both subsonic and supersonic jets, and the results were able to be extrapolated to full-scale engines. This work showed that within the jet plume, water injection clearly disrupts the shock noise sources, leading to a reduction in SAN.

Water injection into the flame trench:

For the water injection, critical parameters were the injection angle, the injection water flow rate and the location of the water injection point. Their results indicated that to achieve any significant noise reduction, the quantity of water injected must be at least three times the jet flow rate.

and more reading.

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created Jul 28, 2018 at 17:03

Hobbes

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The mechanism seems to be related to the bubbles in water rather than the water itself:

Bubbles are excellent at absorbing the sound. They absorb the acoustic energy and as a consequence of which get heated up. NASA exploited this and sprayed water molecules in the air surrounding the Mobile Launcher Platform. This reduced the sound from the firing of the rockets by almost a half! (3 dB)

Further reading in this study:

There are two primary types of water-based acoustic suppression system; a below-deck system where water is injected into the exhaust plume with the aim of reducing far-field noise by more rapid dispersion of the rocket exhaust [12] or an above-deck system where water is injected around the pad.

Norum [16] carried out an extensive investigation into the suppression of dominant noise sources in both subsonic and supersonic jets, and the results were able to be extrapolated to full-scale engines. This work showed that within the jet plume, water injection clearly disrupts the shock noise sources, leading to a reduction in SAN.

Water injection into the flame trench:

For the water injection, critical parameters were the injection angle, the injection water flow rate and the location of the water injection point. Their results indicated that to achieve any significant noise reduction, the quantity of water injected must be at least three times the jet flow rate.

and more reading.