Shock Wave

of an attached shock on a sharp-nosed supersonic body. firing at broadside during training exercises in Puerto Rico, 1984. Circular marks are visible where the expanding spherical atmospheric shockwaves from the gun firing meet the water surface. In mechanics, specifically acoustics, a shock wave, shockwave, or shock is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through matter, energy is preserved but entropy increases.…

of an attached shock on a sharp-nosed supersonic body. firing at broadside during training exercises in Puerto Rico, 1984. Circular marks are visible where the expanding spherical atmospheric shockwaves from the gun firing meet the water surface. In mechanics, specifically acoustics, a shock wave, shockwave, or shock is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through matter, energy is preserved but entropy increases. This change in the matter's properties manifests itself as a decrease in the energy which can be extracted as work, and as a drag force on supersonic objects; shock waves are strongly irreversible processes.

Technological applications

In the examples below, the shock wave is controlled, produced by (ex. airfoil) or in the interior of a technological device, like a turbine.

Combustion engines

The wave disk engine (also named "Radial Internal Combustion Wave Rotor") is a kind of pistonless rotary engine that utilizes shock waves to transfer energy between a high-energy fluid to a low-energy fluid, thereby increasing both temperature and pressure of the low-energy fluid.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1378809741 under CC BY-SA 4.0; modifications have been made.