Reynolds Number

(noun)

A dimensionless number, v ρ l /η, where v is the fluid velocity, ρ the density, η the viscosity and l a dimension of the system. The value of the number indicates the type of fluid flow.

Related Terms

Examples of Reynolds Number in the following topics:

  • Poiseuille's Equation and Viscosity

    • It occurs when the Reynolds number is above a certain critical threshold while mixed turbulent–laminar flow occurs within a range of Reynolds number below this threshold value.
    • At the lower limit of this mixed turbulent–laminar flow Reynolds number region there is another critical threshold value, below which only laminar flow is possible.
    • Laminar flow is often encountered in common hydraulic systems, such as where fluid flow is through an enclosed, rigid pipe; the fluid is incompressible, has constant viscosity, and the Reynolds number is below this lower critical threshold value.
    • Considering laminar flow of a constant density, incompressible fluid such as for a Newtonian fluid traveling in a pipe, with a Reynolds number below the upper limit level for fully laminar flow, the pressure difference between two points along the pipe can be found from the volumetric flow rate, or vice versa.
    • This equation is valid for laminar flow of incompressible fluids only, and may be used to determine a number of properties in the hydraulic system, if the others are known or can be measured.

  • Supply Function

    • QXS = fS(PX, PINPUTS, technology, number of sellers, laws, taxes, expectations . . .

  • Characteristics of Pure Competition

    • Large number of sellers (and buyers), no one of which can influence the market.

  • The Firm in Pure Competition

    • A purely competitive market is characterized by a large number of relatively small firms.
    • Since there are a a large number of firms in the market with identical or homogeneous products, buyers have no preference for any one firm's product.

  • Introduction to Pure Competition

  • The Warren Court

    • The Warren Court (1953-1969), or the Supreme Court of the United States during the period when Earl Warren served as Chief Justice, declared a number of critical cases that expanded civil rights, civil liberties, judicial power, and the federal power in dramatic ways.
    • Board of Education, Reynolds v.
    • Carr and Reynolds v.
    • Wainwright (1963), Reynolds v.

  • Explanation, Prediction and Storytelling

    • Mark Blaug identifies two problems that arise from the "Symmetry Thesis. " First is the problem; "the history of science contains a number of theories which appear to explain natural phenomena, without however predicting them even in a statistical sense" (Blaug, 1986, p 274).

  • Economic objectives

    • In spite of measurement problems, individuals tend to focus on phenomena that can be ranked or associated with a magnitude (or number).

  • Macroeconomics

  • Introduction to the Rules of the Game