expansion shock wave
71Rarefaction — is the reduction of a medium s density, or the opposite of compression. A natural example of this is as a phase in a sound wave or phonon. Half of a sound wave is made up of the compression of the medium, and the other half is the decompression… …
72Ludwieg tube — A Ludwieg tube is a cheap and efficient way of producing supersonic flow. Mach numbers up to 4 are easily obtained without any additional heating of the flow, with heating Mach numbers of up to 11 can be reached.PrincipleA Ludwieg tube is a wind… …
73Chapman–Jouguet condition — The Chapman–Jouguet condition holds approximately in detonation waves in high explosives. It states that the detonation propagates at a velocity at which the reacting gases just reach sonic velocity (in the frame of the lead shock wave) as the… …
74Condensation cloud — A 21 kiloton underwater nuclear weapon test, the Baker shot of Operation Crossroads, showing a Wilson cloud …
75MythBusters (2009 season) — Country of origin Australia United States No. of episodes 23 (includes 3 specials) Broadcast Original channel …
76Mushroom cloud — created by smoke billows Ascending cloud from Redoubt Vol …
77Laser propulsion — is a form of Beam powered propulsion where the energy source is a remote (usually ground based) laser system. This form of propulsion differs from a conventional chemical rocket where both energy and reaction mass come from the solid or liquid… …
78Engine knocking — Pinging redirects here. For other uses, see Ping (disambiguation). Knocking (also called knock, detonation, spark knock, pinging or pinking) in spark ignition internal combustion engines occurs when combustion of the air/fuel mixture in the… …
79Belgium — /bel jeuhm/, n. a kingdom in W Europe, bordering the North Sea, N of France. 10,203,683; 11,779 sq. mi. (30,508 sq. km). Cap.: Brussels. French, Belgique /bel zheek /; Flemish, België /bel khee euh/. * * * Belgium Introduction Belgium Background …
80Lee waves — In meteorology, lee waves, are atmospheric standing waves. The most common form is mountain waves, which are atmospheric internal gravity waves. These were discovered in 1933 by two German glider pilots, Hans Deutschmann and Wolf Hirth, above the …
