I don't use Wiki, I think it diminishes the quality of an exchange
As with all sources of information you need to be selective, and even an expert text may have errors.
M 1.17---is still sonic because every part of the fighter has to reach M 1.00
Definitely not. Your Airbus or Boeing airliner never gets close to Mach 1, but there may be parts of the airframe where the airflow has reached sonic velocities, as being talked about here, the shock wave formation on the wing.
I'm just an aerodynamicist
I hope not.
As the air re-enters the "hole" caused by the A/C in the air behind it, it accelerates and produces an immense release of the energy it was forced to contain during the brief transit of the A/C. This "Thunderclap" is one of two separate events precipitated by the energy of the passing A/C
There are two types of booms: N-waves and U-waves. The N-wave is generated from steady flight conditions, and its pressure wave is shaped like the letter "N." N-waves have a front shock to a positive peak overpressure which is followed by a linear decrease in the pressure until the rear shock returns to ambient pressure. The U-wave, or focused boom, is generated from maneuvering flights, and its pressure wave is shaped like the letter "U." U-waves have positive shocks at the front and rear of the boom in which the peak overpressures are increased compared to the N-wave.
For today's supersonic aircraft in normal operating conditions, the peak overpressure varies from less than one pound to about 10 pounds per square foot for a N-wave boom. Peak overpressures for U-waves are amplified two to five times the N-wave, but this amplified overpressure impacts only a very small area when compared to the area exposed to the rest of the sonic boom.
The strongest sonic boom ever recorded was 144 pounds per square foot and it did not cause injury to the researchers who were exposed to it. The boom was produced by a F-4 flying just above the speed of sound at an altitude of 100 feet.
In recent tests, the maximum boom measured during more realistic flight conditions was 21 pounds per square foot. There is a probability that some damage -- shattered glass, for example, will result from a sonic boom. Buildings in good repair should suffer no damage by pressures of less than 16 pounds per square foot. And, typically, community exposure to sonic boom is below two pounds per square foot. Ground motion resulting from sonic boom is rare and is well below structural damage thresholds accepted by the U.S. Bureau of Mines and other agencies. (USAF FACT SHEET 96-03)
For students interested in aerodynamics NASA have a good site here
http://www.grc.nasa.gov/WWW/K-12/airplane/guided.htm With the caveat that even the experts can get it wrong (I’m no expert, just an interested bystander) I think even airfoilmod will find it an acceptable source of information. If NASA can't get it right we really are in big trouble.
I reference this site because of the facility to play around with numbers to see what occurs.
You say there is no increase in energy? That wants explanation
Not sure as to what you are referring exactly airfoil. I admit to be being a little slow.