Mach

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Related to Mach numbers: Mach speed

Mach

Ernst . 1838--1916, Austrian physicist and philosopher. He devised the system of speed measurement using the Mach number. He also founded logical positivism, asserting that the validity of a scientific law is proved only after empirical testing

Mach

Machclick for a larger image
Speed of sound as a function of altitude.
Machclick for a larger image
Refers to a Mach number, or the ratio of the speed of an airplane to the speed of sound in the same atmospheric conditions. It is also used as a speed unit. The speed of sound, or Mach 1, is equal to 340.5 m/s, 661 knots, 761 miles per hour, or 1225.5 km/h at sea level under standard conditions, and it decreases with altitude. Above the tropopause (about 36,090 ft, or 11 km), Mach 1 is 295.5 m/s, 574 knots, 658 miles per hour, or 1063.2 km/h. Named after Ernst Mach (1838–1916).

Mach

An operating system kernel under development at Carnegie-Mellon University to support distributed and parallel computation. Mach is designed to support computing environments consisting of networks of uniprocessors and multiprocessors. Mach is the kernel of the OSF/1.

Mach kernel

A Unix-like operating system developed at Carnegie-Mellon University in the period between 1985 and 1994. It was designed with a microkernel architecture that makes it easily portable to different platforms. Operating systems based on Mach include NextStep, OSF/1 and Mac OS X. See microkernel, Mac OS X and Open Group.
References in periodicals archive ?
Effect of subsonic inlet lip geometry on predicted surface and flow mach number distributions, National Aeronautics and Space Administration, [online] [accessed 19 May.
However, it is time-consuming to generate the training data via any direct CFD simulations when both Mach number and mean angle of attack are taken into consideration.
Mach number, separation distance, angle of attack, and airfoil thickness were also varied in the 2D simulations.
Then the spatial variation of velocity, vorticity, shock, Mach number, species concentration, and temperature are presented and discussed in depth.
We must, however, immediately underline that the onset of KH instability in incompressible magnetic flux tube always requires slightly greater threshold Alfveen Mach numbers and correspondingly higher critical jet speeds.
The effects of parameters such as Mach number, dynamic pressure, and temperature on aerodynamic nonlinearity are discussed in Section 3.
The static pressure rise is achieved through the ramming effect of the air; the increase in Mach number results in increase in static pressure and static temperature with the loss of stagnation pressure due to the presence of shock waves.
It is found that the disturbance amplitude obtained by experiments agrees well with the linear stability theory (LST) result when the freestream Mach number is less than 2.2.
However, performance studies done by FRDC engineer Bob Abernethy showed that for a J58 application requiring continuous high Mach number afterburner operation, ducting compressor bleed air directly into the afterburner not only eliminated the stall margin limits, but it also provided better engine performance.
The exhaust velocities, Mach numbers, and mass flow rates are largely fixed by the engine cycle, and one has little freedom to alter them.
The collision frequency distribution curves under different Mach numbers, when the incidence wave is normal to surface, are described in Figure 5.
One of the critical parameter in the gas atomization process is the Mach number. The exit velocity of the gas jet in the atomization process controls the extent of the metal breakup.