Supersonic pressure wave

Sept 1958) (Abnormally high deton pressures in a shock tube) 11) W.H. Sargent R.A. Gross, "A Detonation Wave Supersonic Ramjet , AFOSR 59-589, ASTIA 216811 (June 1959) 12) H.W. Hubbard 8c M.H. 

If the velocity of the reaction becomes fast enough and the reaction is sufficiently exothermic, the adiabatic expansion of our reacting zone will occur at a linear rate comparable with the velocity of sound. Under such circumstances a sharp pressure wave begins to be built up ahead of the reaction zone, and it can propagate as a shock wave of supersonic velocity in the unburned gases.As the shock front passes through the reaction mixture, it produces adiabatic compression. If the temperature in this adiabatically compressed zone behind the shock wave exceeds the... 

Whereas in the case of an explosion the pressure wave propagates at a subsonic rate, the speed of pressure propagation in the case of a detonation is much higher and lies in the supersonic range. At normal temperatures, a detonation will not be... 

Large-amplitude nonlinear pressure wave produced in a supersonic field or flow. The fluid passing through this discontinuity undergoes a finite decrease in velocity accompanied by a marked increase in pressure, density, temperature, and entropy. 

Aircraft traveling faster than the speed of sound create a sonic boom, a large pressure wave experienced as an explosion. This stardes people, breaks windows, and damages structures. Commercial aircraft are therefore prohibited from flying at supersonic speeds over land areas. 

An increase in flame velocity causes significant combustion wave overpressure rise. A supersonic combustion wave, with respect to the laboratory coordinate system, forms compression and shock waves propagating ahead of the flame front. The pressure wave profile is determined by the flame acceleration, the resulting flame velocity and the geometry. 

Blast wave Fast air pressure change propagating in the form of a pressure perturbation away from the blast epicenter. The leading front pressure jump is known as a shock wave, it is called a compression wave when the pressure rise grows with a moderate velocity. A low intensity pressure wave moves with the sound speed in the surroundings. Finite intensity shock/blast waves propagate with supersonic speed. 

There are certain limitations on the range of usefulness of pitot tubes. With gases, the differential is very small at low velocities e.g., at 4.6 m/s (15.1 ft/s) the differential is only about 1.30 mm (0.051 in) of water (20°C) for air at 1 atm (20°C), which represents a lower hmit for 1 percent error even when one uses a micromanometer with a precision of 0.0254 mm (0.001 in) of water. Equation does not apply for Mach numbers greater than 0.7 because of the interference of shock waves. For supersonic flow, local Mac-h numbers can be calculated from a knowledge of the dynamic and true static pressures. The free stream Mach number (MJ) is defined as the ratio of the speed of the stream (V ) to the speed of sound in the free stream ... 

Finally, we note that if the body is moving at speeds near and above the speed of sound (transonic and supersonic speeds), shock waves will occur that increase the pressure on the front portions of the body, contributing an additional source of pressure drag called wave drag. 

Shock waves travel at supersonic velocities and exhibit a near discontinuity in pressure, density, and tempera-... 

Physically speaking, shock waves are compaction waves with a vertical shock front, which occur in supersonic fluxes or as described above the pressure reaches a maximum value and then falls rapidly towards zero. Shock waves can also occur in space, which is almost free of matter, via interactions of electrical and magnetic fields (Sagdejev and Kennel, 1991). 

Condition (g) is that condition for which the exit pressure is equal to the back pressure and no shock wave occurs. This is called the design condition for supersonic flow. 

In regime 4, which extends over all values of the back pressure lower than the supersonic design pressure, the adjustment from the exit pressure to the lower back pressure occurs as an oblique expansion shock wave outside the nozzle this is the case for condition (h). 

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