Froude number


Froude number

      in hydrology and fluid mechanics, dimensionless quantity used to indicate the influence of gravity on fluid motion. It is generally expressed as F = v/(gd)-1/2, in which d is depth of flow, g is the gravitational acceleration (equal to the specific weight of the water divided by its density, in fluid mechanics), v is the celerity of a small surface (or gravity) wave, and F is the Froude number. When F is less than 1, small surface waves can move upstream; when F is greater than 1, they will be carried downstream; and when F = 1 (said to be the critical Froude number), the velocity of flow is just equal to the velocity of surface waves. The Froude number enters into formulations of the hydraulic jump (rise in water surface elevation) that occurs under certain conditions, and, together with the Reynolds number (q.v.), it serves to delineate the boundary between laminar and turbulent flow conditions in open channels.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Froude Number —  Froude Number  Число Фруда   Один из критериев подобия движения жидкостей и газов, является безразмерной величиной. Применяется в случаях, когда существенно воздействие силы тяжести. Число Фруда характеризует соотношение между силой инерции и… …   Толковый англо-русский словарь по нанотехнологии. - М.

  • Froude number — The Froude number is a dimensionless number comparing inertial and gravitational forces. It may be used to quantify the resistance of an object moving through water, and compare objects of different sizes. Named after William Froude, the Froude… …   Wikipedia

  • Froude number —    A dimensionless numerical quantity used as an index to characterize the type of flow in a hydraulic structure that has the force of gravity (as the only force producing motion) in conjunction with the resisting force of inertia. It is the… …   Lexicon of Cave and Karst Terminology

  • Froude number — noun A dimensionless number defined as the ratio of a characteristic velocity to a gravitational wave velocity, used in fluid mechanics to determine the resistance of an object moving through water …   Wiktionary

  • Froude number — Смотри число Фруда (Fr) …   Энциклопедический словарь по металлургии

  • Froude number — …   Useful english dictionary

  • Froude — The following three are brothers.* Hurrell Froude (1803 1836), Anglican priest * James Anthony Froude (1818 1894), British historian * William Froude (1810 1879), British engineeree also* Froude number …   Wikipedia

  • Froude, William — born Nov. 28, 1810, Dartington, Devon, Eng. died May 4, 1879, Simonstown, S.Af. British engineer and naval architect. He was the brother of James Anthony Froude. In 1837 he became an assistant to I.K. Brunel, for whom he oversaw railway… …   Universalium

  • Froude resistance curve — The Froude resistance curve is a limitation on the speed conventional displacement ships may achieve.Hydrofoil, planing, and submerged buoyancy [http://ness.external.lmco.com/nessb/ship systems/applications/seaslice.html] craft are able to exceed …   Wikipedia

  • Morton number — For Morton number in number theory, see Morton number (number theory). In fluid dynamics, the Morton number (Mo) is a dimensionless number used together with the Eötvös number to characterize the shape of bubbles or drops moving in a surrounding… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.