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1
Sonic Booms
Dr Katerina Kaouri
Outline
• Supersonic aircraft
• Sonic Booms
• Where do sonic booms land?
• How loud are sonic booms?
F-14 breaking the sound barrier
What do you hear?
4
•What is a Sonic boom?
Sound created by an object
traveling faster than sound
• Thunder-like sound
Concorde: Mach 2
Basics of Sound
• Sound needs material (e.g. air) in order to
travel
• Sound travels at 340m/s (1200Km/h) in the air
- One...
7
Still sourceStill source
Still source
Wavefronts are circles -they all grow at the speed of sound
Moving source: Mach number
Mach numberMach number =ratio of
aircraft speed to sound speed
•Subsonic aircraft: Mach < 1
•Su...
9
Subsonic source Supersonic source
Sound source movesSound source moves
Wavefronts are nested Wavefronts overlap and form...
10
Mach
Cone
Photo from: NASA
Hyperbol
a
In this way we can calculate the area affected
by sonic booms
In 3D: The Mach cone cuts the ground
Boom carpet
How loud are sonic booms?
N-wave
The N-wave is continuously emitted from a supersonic aircrqaft
-Like we are throwing ston...
A supersonic car also produces sonic
booms
Mach
Cone
•Name: ThrustSSC
•World's first Supersonic land
speed Record (1km in ...
Sonic booms in nature
• Thunders
• Volcanoes (Kracatoa, 1883)
• Meteorites falling to Earth
15
“It was the sonic boom that caused the destruction –
not the actual landing of the meteorite.” M. Grady,
Professor of P...
Do the following produce sonic
booms?
Space Shuttles
Bullets
Bullwhips
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Sonic booms kaouri-2015

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A popularised talk on sonic booms-suitable for the public but also as school lesson material.
Note: This talk (and similar versions of it) have been delivered several times to diverse audiences since 2004

Published in: Education
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Sonic booms kaouri-2015

  1. 1. 1 Sonic Booms Dr Katerina Kaouri
  2. 2. Outline • Supersonic aircraft • Sonic Booms • Where do sonic booms land? • How loud are sonic booms?
  3. 3. F-14 breaking the sound barrier What do you hear?
  4. 4. 4 •What is a Sonic boom? Sound created by an object traveling faster than sound • Thunder-like sound Concorde: Mach 2
  5. 5. Basics of Sound • Sound needs material (e.g. air) in order to travel • Sound travels at 340m/s (1200Km/h) in the air - One million times slower than light (We see lightnings and then hear their sound) • Sound travels along rays (similar to light rays) Almost everything around us produces sound
  6. 6. 7 Still sourceStill source Still source Wavefronts are circles -they all grow at the speed of sound
  7. 7. Moving source: Mach number Mach numberMach number =ratio of aircraft speed to sound speed •Subsonic aircraft: Mach < 1 •Supersonic aircraft: Mach > 1 (Concorde: Mach 2)Ernst Mach, 1838-1916
  8. 8. 9 Subsonic source Supersonic source Sound source movesSound source moves Wavefronts are nested Wavefronts overlap and form Mach wedge
  9. 9. 10 Mach Cone Photo from: NASA
  10. 10. Hyperbol a In this way we can calculate the area affected by sonic booms In 3D: The Mach cone cuts the ground Boom carpet
  11. 11. How loud are sonic booms? N-wave The N-wave is continuously emitted from a supersonic aircrqaft -Like we are throwing stones out of a car continuously -It is heard as a single boom by human ears overpressure recovery •Pressure signature Overpressure From aircraft nose Underpressure from aircraft tail
  12. 12. A supersonic car also produces sonic booms Mach Cone •Name: ThrustSSC •World's first Supersonic land speed Record (1km in 2.9s) •Where: Blackrock Desert, Nevada •When: 15th October 1997 •Who: Andy Green (driver), Ron Ayers (engineer)
  13. 13. Sonic booms in nature • Thunders • Volcanoes (Kracatoa, 1883) • Meteorites falling to Earth
  14. 14. 15 “It was the sonic boom that caused the destruction – not the actual landing of the meteorite.” M. Grady, Professor of Planetary Science Meteorite falling in Russia! Meteorite: Mach 50 Meteorite FallMeteorite Fall Russia 15 Feb, 2013
  15. 15. Do the following produce sonic booms? Space Shuttles Bullets Bullwhips

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