# parabolic velocity

## parabolic velocity

(pa-ră-bol -ik) The velocity of an object following a parabolic trajectory around a massive body. Its velocity at a given distance from the massive body is equal to the escape velocity at that distance.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

## Parabolic Velocity

the velocity required for a body—for example, a space probe or an atmospheric particle—to escape from the gravitational field of an attracting body, such as the earth, the moon, or a planet, in a parabolic orbit. It decreases with the distance from the attracting body. Parabolic velocity is an example of a critical spacecraft velocity.

## parabolic velocity

[¦par·ə¦bäl·ik və′läs·əd·ē]
(astronomy)
The velocity attained by a celestial body in a parabolic orbit.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
[u.sub.s](r) is steady parabolic velocity of blood flow, which is relation to the corresponding Poiseuille flow velocity in steady blood flow; [u.sub.[phi]](r, t) represents the oscillatory velocity of blood flow in the rigid blood vessel; [u.sub.ave] is the average velocity of blood flow; [mu] is dynamic viscosity of blood; [eta] = [r.sub.0]/[square root of [mu]/[[rho].sub.b][[omega].sub.p]] is the Womersley number; fac characterizes the relative intensity of the pulsatile flow; [[omega].sub.p] is the angular frequency of heartbeat; [f.sub.p] = [[omega].sub.p]/2[pi] denotes the heartbeat frequency varied from 1 to 3Hz ; and [J.sub.0] is zero-order Bessel function of the first kind.
Though discussions in the above paragraph refer to entry length and entry conditions at the pipe entry, the discussions in Massey (1984) are associated with the formation and development of boundary layers up to a point where a uniform parabolic velocity profile has been reached.
It is clear that the parabolic velocity profile was developed in the pressure-driven flow.
In practice, the taper angle is higher at the top surface of the work piece where the jet has a parabolic velocity profile.
The ratio [L.sub.e]/D [1.75/2.2] = 0.8 shows that a parabolic velocity profile is fully developed about one-third of a diameter's length from the inhalant opening; hence entrance effects may be ignored.
In general, field-flow fractionation is employing a laminar flow of a carrier liquid between two walls, which are placed at a short distance from each other and creates a parabolic velocity profile with zero carrier velocity at the walls and the maximum velocity along the centre axis of the so formed open channel.
The velocity field through the pipe is obtained and inlet length section [z.sub.L] is calculated after which a parabolic velocity profile occurs.
showed that the simplifying assumptions of parabolic velocity profile, constant physical properties and isothermal operation conditions were sufficient to describe reasonably well the experimental dynamic behavior of a tubular reactor carrying out the solution polymerization of styrene, in spite of the significant flow distortions expected at the analyzed operation conditions, as computed with the help of a very detailed reactor model.
As the flow rate is constant in a cross-section of the channel, the parabolic velocity profile is not influenced by the wall roughness.

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