How Far Away Can You Hear a Sonic Boom

Yes, a sonic boom produced at 60,000' tin exist heard on the basis.

Outset of all, a sonic boom consist in a steep increase of air pressure level, followed by a slow, linear subtract below the nominal ambience pressure, and again a steep increase dorsum to the nominal pressure. It is therefore called N-shaped moving ridge or just Due north-wave. Here is a graph with several sonic booms, measures past NASA and found on Wikipedia:

The same wiki folio cites a document from NASA

          Shipping        speed   distance        pressure                [mach]   [ft (m)]        [lb/ft² (Pa)]  SR-71           3      80,000 (24,000)  0.ix  (43) Concorde SST    2      52,000 (16,000)  1.94 (93) F-104           one.93   48,000 (15,000)  0.8  (38) Space Shuttle   ane.5    60,000 (eighteen,000)  1.25 (lx)                  

These measurements are from aircraft with different distance. As sound pressure level depends from altitude like $p\sim\frac{1}{r}$, one may calculate the pressure for a certain distance as in the post-obit tabular array. However, this assumes that the aircraft causes the same "blast intensity" at that altitude, which you lot should doubt at least for the SR-71.

          Aircraft        speed   altitude        pressure level                [mach]   [ft (thousand)]        [lb/ft² (Pa)]  SR-71           3      48,000 (15,000)  1.44 (69) Concorde SST    2      48,000 (15,000)  2.07 (99) F-104           ane.93   48,000 (fifteen,000)  0.eight  (38) Space Shuttle   1.v    48,000 (15,000)  ane.5  (72)                  

As you tin can see, the Concorde is the loudest aircraft, the most comparable F-104 (speed, altitude) produces just forty% of its audio pressure level. Just the F-104 is also much much smaller than the Concorde.

The Space Shuttle is very loud for its depression speed. However, information technology looks more similar a flight brick than an elegant, streamlined shipping, and so no wonder that it creates strong shock waves.

The SR71 seems to be very repose for its speed, but as said, I don't think you lot tin pull it down to 48000ft and expect the same behaviour. However, a sonic boom starts to disperse in some (larger) distance, may be this already happened for the SR-71. (Also, it's a spy plane with a very special shape - may be, this reduces the boom, too).

---

Information technology has to be said that it is hard to translate the numbers into a comparable sound level, considering what makes upwards the loudness is non only the maximum pressure level, just too the ascension time.
As counter-example, the air pressure changes by 130Pa every meter of altitude (at footing), and you don't hear the alter of pressure when standing up from your chair (~100kPa)

Too, a sudden noise appears to be much louder than a noise slowly increasing to the same level - and the blindside has the virtually sudden wave class possible. (Listen loud music with earphones - when the player clips a second, the first moment afterward really hurts)

However, at that place is a long table on Wikipedia list noise sources and their levels. For case:

          Trumpet at 0.5m:                63Pa Jack hammer at 1m:               2Pa  (I'd say: a little quite...) Loudest human voice at 1 inch: 110Pa                  

These levels are effective sound pressure. To translate a perfect North-wave with given maximum pressure to effective pressure level, you lot have to multiply the value past $\frac{1}{\sqrt{3}}\approx0.577$.

Thus, the sonic boom of the Concorde has an effective value of 57Pa, which is comparable to the trumpet in 0.5m distance.

(Every bit said, there is even so a difference, considering the boom is a sharp, brusk dissonance, merely information technology gives an idea.)

---

By the way, I just stumbled on another certificate, about primary and secondary sonic booms.

It states that you hear a master sonic boom coming from the aircraft within a lateral distance of ~20nm (solid lines) also as a secondary boom within a distance of 60-85nm (dashed lines). This secondary waves are a reflection of the upwardly travelling shockwaves from the aircraft at the atmosphere. The secondary nail is non a brusk, loud blindside, but a longer and less intense rumbling, making information technology hard to identify the source.

lopezsentur.blogspot.com

Source: https://aviation.stackexchange.com/questions/17661/can-a-sonic-boom-produced-at-60-000-be-heard-on-the-ground

Share this post