Fr.: pression de son
The periodic fluctuation above and below atmospheric pressure created by an oscillating body which provides the → sound power. Instantaneous sound pressure is the peak value of air pressure.
Fr.: pression de stagnation
standard temperature and pressure (STP)
damâ o fešâr-e estândé
Fr.: conditions normales de température et de pression
1) The most commonly used definition is temperature of 273.15 K (0 °C) and
pressure of 1 → atmosphere.
Fr.: pression statique
In → fluid mechanics, the → pressure felt by an object suspended in a → fluid and moving with it. This pressure is called static because the object is not moving relative to the fluid. See also → dynamic pressure.
fešâr-e garmâyi (#)
Fr.: pression thermale
The ordinary pressure in a gas that is due to motions of particles and can be attributed to the object's → temperature.
Fr.: pression totale
Fr.: pression de vapeur
The equilibrium pressure of a vapor above its condensed phases (liquid or solid). In other words, the pressure of the vapor resulting from evaporation of a liquid (or solid) above a sample of the liquid (or solid) in a closed container. The vapor pressure varies with the temperature. As the temperature increases its the vapor pressure also increases, and conversely. The temperature at which the vapor pressure is equal to the atmospheric pressure is called the → boiling point. For example, at 20 °C, water would boil at a pressure of about 0.023 atm, or about a fortieth of atmospheric pressure.
Fr.: pression dynamique