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Pressure as a function of the height above the sea level. There are two equations for computing pressure as a function of height. The first equation is applicable to the atmospheric layers in which the temperature is assumed to vary with altitude at a non null lapse rate of : = [,, ()] ′, The second equation is applicable to the atmospheric layers in which the temperature is assumed not to ...
The meter is "read" as a differential pressure head in cm or inches of water and is equivalent to the difference in velocity head. The dynamic pressure, along with the static pressure and the pressure due to elevation, is used in Bernoulli's principle as an energy balance on a closed system .
In aviation, pressure altitude is the height above a standard datum plane (SDP), which is a theoretical level where the weight of the atmosphere is 29.921 inches of mercury (1,013.2 mbar; 14.696 psi) as measured by a barometer. [2]
In fluid dynamics, total dynamic head (TDH) is the work to be done by a pump, per unit weight, per unit volume of fluid.TDH is the total amount of system pressure, measured in feet, where water can flow through a system before gravity takes over, and is essential for pump specification.
An airspeed indicator for an aeroplane. Indicated airspeed is displayed on the black background (in this case both in knots (kn) and miles per hour (mph)). The pilot sets the pressure altitude and air temperature in the top window using the knob. Based on that, the white background scale in the lower left window moves to give true airspeed.
The orthometric height (symbol H) is the vertical distance along the plumb line from a point of interest to a reference surface known as the geoid, the vertical datum that approximates mean sea level. [1] [2] Orthometric height is one of the scientific formalizations of a layman's "height above sea level", along with other types of heights in ...
Its symbol is m/h or m·h −1 (not to be confused with the imperial unit symbol mph). By definition, an object travelling at a speed of 1 m/h for an hour would move 1 metre. The term is rarely used however as the units of metres per second and kilometres per hour are considered sufficient for the majority of circumstances. Metres per hour can ...
Pivotal altitude is the height for a given ground speed at which the line of sight from the cockpit directly parallel to the lateral axis of the aircraft will remain stationary on an object on the ground. A good rule of thumb for estimating the pivotal altitude is to square the groundspeed, then divide by 15 (if the groundspeed is in miles per ...