* Compressible: According to Miller, " Uncompressed digital data is very large, and in its raw form would actually produce a larger signal ( therefore be more difficult to transfer ) than analog data.

Compressible flow is the area of fluid mechanics that deals with fluids in which the fluid density varies significantly in response to a change in pressure.

Compressible flow describes the behaviour of fluids that experience significant variations in density.

Compressible flows play a big role in determining the behaviour of nozzles.

Source: Aerodynamics of a Compressible Fluid.

* Liepmann H. W. and A. E. Pucket, Introduction to Aerodynamics of a Compressible Fluid, John Wiley and Sons, Inc. 1947

* Richard von Mises, Mathematical Theory of Compressible Fluid Flow.

* Compressible the PST data is encrypted with a byte-substitution cipher with a fixed substitution table.

* 1917 James Hopwood Jeans, The Configurations of Rotating Compressible Masses.

* Incompressible subsonic current: < math > 0 < M < 0. 3 </ math >

The missile was entirely subsonic, powered by a turbofan engine with a rocket booster assisting at launch .< sup id =" fn_3_back "> 3 </ sup >

While subsonic engines had made great strides in increased efficiency through the 1960s with the introduction of the turbofan engine with ever-increasing bypass ratios, the fan concept is difficult to use at supersonic speeds where the " proper " bypass is about 0. 45, as opposed to 2. 0 or higher for subsonic designs.

Their Critical Mach numbers are higher than those of subsonic and transonic aircraft but still less than Mach 1. 0.

The aircraft will be subsonic, and traveling significantly below Mach 1. 0, when it first experiences this effect.

However, the accelerated airflow over the upper surface of the cambered wing exceeds Mach 1. 0 and a shock wave is created at the point on the wing where the accelerated airflow returns from supersonic to subsonic airflow.

The HF-2E block I missile's cruising speed is high subsonic, typically between Mach 0. 75-0. 85 range.

A problem is called subsonic if all the speeds in the problem are less than the speed of sound, transonic if speeds both below and above the speed of sound are present ( normally when the characteristic speed is approximately the speed of sound ), supersonic when the characteristic flow speed is greater than the speed of sound, and hypersonic when the flow speed is much greater than the speed of sound.

Eastman Jacobs, working for NACA, presented his optimized airfoils for high subsonic speeds which led to some of the high performance American aircraft during World War II.

By the time the sound barrier was broken, much of the subsonic and low supersonic aerodynamics knowledge had matured.

There are several branches of subsonic flow but one special case arises when the flow is inviscid, incompressible and irrotational.

In solving a subsonic problem, one decision to be made by the aerodynamicist is whether to incorporate the effects of compressibility.

Supersonic flow behaves very differently from subsonic flow.

In fluid traveling at subsonic speed, this pressure disturbance can propagate upstream, changing the flow pattern ahead of the object and giving the impression that the fluid " knows " the object is there and is avoiding it.

The presence of shock waves, along with the compressibility effects of high-velocity ( see Reynolds number ) fluids, is the central difference between supersonic and subsonic aerodynamics problems.

The product line was broad and came to include ammunition, grenades, mines, armored personnel vehicles, patrol boats, navy patrol planes, turboprop trainers, tanks, and subsonic jet fighters.

In December 1974 the Navy Flight Demonstration Team downsized to the subsonic Douglas A-4F Skyhawk II and was reorganized into the Navy Flight Demonstration Squadron.

Modern cruise missiles can travel at supersonic or high subsonic speeds, are self-navigating, and can fly on a non-ballistic, extremely low altitude trajectory.

Cruise missiles can be categorized by size, speed ( subsonic or supersonic ), and range, and whether launched from land, air, surface ship, or submarine.

They are equipped with a TERCOM system which allows them to cruise at an altitude lower than 110 meters at subsonic speeds while obtaining a CEP accuracy of 15 meters with an Inertial navigation system.

Laminar flow wings, which improved high speed performance, also came into use on fighters such as the P-51, while the Messerschmitt Me 262 and the Messerschmitt Me 163 featured swept wings that dramatically reduced drag at high subsonic speeds.

This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation.

Low explosives deflagrate at subsonic speeds, whereas high explosives detonate, producing a supersonic wave.

In fact, for typical airfoils at subsonic speeds the top surface contributes more flow turning than the bottom surface, and the pressure deviation along the top is significantly larger than along the bottom.

It also has Su-25 close-support aircraft, Mi-25 attack helicopters, Mi-17 transport helicopters, Aermacchi MB-339, Embraer EMB-312 Tucano subsonic training aircraft, and the Cessna A-37B for light attack and COIN missions.

Thus jet engines, with a better match between speed and jet exhaust speed ( such as turbofans )— in spite of their worse )— dominate for subsonic and supersonic atmospheric use, while rockets work best at hypersonic speeds.

Submachine guns lend themselves to moderation with suppressors, particularly so in cases where the weapon is loaded with subsonic ammunition.

Of dozens of VTOL and V / STOL designs tried from the 1950s to 1980s, only the subsonic Hawker Siddeley Harrier and Yak-38 Forger reached operational status, with the Forger being withdrawn after the fall of the Soviet Union.

The gasflow in most turbines employed in gas turbine engines remains subsonic throughout the expansion process.

In a transonic turbine the gasflow becomes supersonic as it exits the nozzle guide vanes, although the downstream velocities normally become subsonic.

Wings with this shape are the norm in subsonic flight, but symmetrically shaped wings ( above and below ) can generate lift by using a positive angle of attack to deflect air downward.

Jet fighters and other supersonic aircraft that do not spend a great deal of time supersonic also often use turbofans, but to function, air intake ducting is needed to slow the air down so that when it arrives at the front of the turbofan, it is subsonic.