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- Karman street = Karman vortex street.
- Karman vortex street
- (After Theodore von Karman, 1881-1963, Hungarian-born American scientist).
A double trail of vortices
formed alternately on both sides of a cylinder or similar body moving at right
angles to its axis through a fluid, the
cortices in one row rotating in a direction opposite to that of the other row.
- A frequency
band used in radar extending
approximately from 10.9 gigacycles per second to 36 gigacycles per second.
- That portion of the radiation from the solar corona
consisting of the continuous
spectrum scattered by electrons.
- In radar, a modified A-display in
which a target appears
as a pair of vertical deflections or blips instead of
a single deflection. When the radar antenna is
correctly pointed at the target in azimuth, the blips are of equal height.
When not correctly pointed, the difference in blip height is an indication of
direction and magnitude of azimuth pointing error. Also called K-scan,
- Kelvin scale = Kelvin temperature scale.
- Kelvin temperature scale (abbr K)
- An absolute
temperature scale independent of the thermometric properties of the
working substance. On this scale, the difference between two temperatures T1
and T2 is proportional to the heat converted into mechanical work by a Carnot
engine operating between the isotherms and
through T1 and T2. Also called absolute temperature scale, thermodynamic
- For convenience the Kelvin is identified with the Celsius degree. The
ice point in the Kelvin scale is 273.15 degrees K. The triple point of water,
the fundamental reference points, is 273.16 degrees K. See absolute
absolute temperature scale, Rankine
- Kennelly-Heaviside layer = E-layer.
- Kepler equation
- In celestial mechanics M = E - e sin E where
M is mean anomaly; E is eccentric anomaly; and e is
eccentricity of the orbital ellipse. See anomaly, note.
- Pertaining to motion in conformance with Kepler
laws, as Keplerian trajectory, Keplerian ellipse.
- Kepler laws
- The three empirical laws governing the motions of planets in their orbits,
discovered by Johannes Kepler (1571-1630). These are: (a) the orbits of the
planets are ellipses, with
the sun at a common focus; (b) as a planet moves in its orbit, the line
joining the planet and sun sweeps over equal areas in equal intervals of time
(also called law of equal areas ); (c) the squares of the periods of
revolution of any two planets are proportional to the cubes of their mean
distances from the sun.
- Kepler planetary laws = Kepler laws.
- kilo (abbr k)
- Prefix meaning multiplied by 1000.
- kilocalorie (abbr kcal)
- See calorie.
- kilocycle (abbr kc)
- One thousand cycles or 1000 cycles per second.
- kilogram (abbr kg)
- The unit of mass in the metric system; the mass of the International
Prototype Kilogram, a cylinder of platinum-iridium alloy, stored at Seures,
France, by the International Bureau of Weights and Measures.
- kilogram calorie (abbr kg-cal, Kcal, Cal)
- See calorie.
- kilomegacycle = gigacycle.
- kilometer (abbr km)
- A unit of distance in the metric system.
- 1 kilometer = 3280.8 feet = 1093.6 yards = 1000 meters = 0.62137
statute miles = 0.53996 nautical miles.
- kilometric waves
- See frequency
- K-indicator = K-display.
- K-indices = magnetic K-indices.
- kinematic eddy viscosity
- See kinematic
- The branch of mechanics dealing with the description of the motion of
bodies or fluids without reference to the forces producing the motion.
- kinematic viscosity (symbol v)
- A coefficient
defined as the ratio of the dynamic
viscosity of a fluid to its
- The kinematic viscosity of most gases increases with increasing
temperature and decreasing pressure. For dry air at 0 degrees C, the kinematic
viscosity is about 0.13 square centimeter per second. In the theory of
atmospheric turbulence the kinematic viscosity is usually replaced by the
kinematic eddy viscosity to account for the increased internal friction due to
- kinetic energy (symbol Ek)
- The energy which a
body possesses as a consequence of its motion, defined as one-half the product
of its mass m and the square of its speed v, 1/2 mv2. The kinetic energy per unit volume of a
fluid parcel is the 1/2 p v2 , where p is the density and v
the speed of the parcel. See potential
- For relativistic speeds the kinetic energy is given by Ek =
mc2 - m0c2 where c is the velocity of light in a vacuum, m0 is the rest mass, and m is the moving mass.
- kinetic-energy equation = mechanical-energy equation.
- kinetic pressure = dynamic pressure.
- kinetic theory
- The derivation of the bulk properties of fluids from the
properties of their constituent molecules,
their motions, and interactions.
- kink instability
- In plasma
physics, a kinking or bending of a current-carrying filament in the pinch
- If a slight bend forms in the plasma column of a pinch, the magnetic
forces are such as to increase the bend and the column is unstable.
- Kirchhoff law
- The radiation
law which states that at a given temperature the ratio of the emissivity
to the absorptivity
for a given wavelength is the same for all bodies and is equal to the
emissivity of an ideal black body
at that temperature and wavelength.
- Loosely put, this important law asserts that good absorbers of a given
wavelength are also good emitters of that wavelength. It is essential to note
that the Kirchhoff law relates absorption and emission at the same wavelength
and at the same temperature. Also called Kirchhoff radiation law.
- An electron
tube for converting direct-current energy into radio frequency energy by
alternately speeding up and slowing down the electrons. See magnetron.
- A nautical mile per hour, 1.1508 statute miles per hour.
- Knudsen flow
- The flow of gases through
ducts and tubes under conditions intermediate between laminar viscous
flow and molecular
flow. Also called transition flow.
- Knudsen gage
- A gage which measures pressure in terms of the net rate of transfer of momentum by molecules
between two surface maintained at different temperatures and separated by a
distance smaller than the mean free
path of the gas molecules. Also called radiometer vacuum gage.
- Various types of Knudsen gage are distinguished by the names of the
inventors and differ mainly in the shape and method of suspension of the
- Knudsen number
- A number used to describe the flow of a low density gas, equal to the
ratio λ/l where λ is the mean free path of the gas molecule and l
is a characteristic length, such as boundary layer thickness, or apparatus
- The Knudsen number is used most commonly to define the extend to which
the gas behaves like a collection of independent particles (free-molecule
regime, Knudsen number much larger than unity), or like a viscous fluid
(continuous regime, Knudsen number much smaller than unity). Intermediate
regimes are termed transition region, and slip flow
region. See rarefied
gas dynamics, note.
- Knudsen rate of evaporation = maximum evaporation rate.
- K-scan = K-display.
- K-scope = K-display.