# Laminar flow

Laminar flow

Laminar flow, sometimes known as streamline flow, occurs when a fluid flows in parallel layers, with no disruption between the layers. In fluid dynamics, laminar flow is a flow regime characterized by high momentum diffusion, low momentum convection, pressure and velocity independent from time. It is the opposite of turbulent flow. In nonscientific terms laminar flow is "smooth," while turbulent flow is "rough."

The dimensionless Reynolds number is an important parameter in the equations that describe whether flow conditions lead to laminar or turbulent flow. Reynolds numbers of less than 2000 are generally considered to be of a laminar type. When the Reynolds number is much less than 1, Creeping motion or Stokes flow occurs. This is an extreme case of laminar flow where viscous (friction) effects are much greater than inertial forces.

For example, consider the flow of air over an airplane wing. The boundary layer is a very thin sheet of air lying over the surface of the wing (and all other surfaces of the airplane). Because air has viscosity, this layer of air tends to adhere to the wing. As the wing moves forward through the air, the boundary layer at first flows smoothly over the streamlined shape of the airfoil. Here the flow is called "laminar" and the boundary layer is a laminar layer.

For a practical demonstration of laminar and non-laminar flow, one can observe the smoke rising off a cigarette in a place where there is no breeze. The smoke from the cigarette will rise vertically and smoothly for some distance (laminar flow) and then will start undulating into a turbulent, nonlaminar flow.

External links

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* Laminar flow in a pipe
* [http://www.hrs-spiratube.com/en/resources/comparison-of-laminar-and-turbulent-flow.aspx Comparison of laminar and turbulent flow]

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### Look at other dictionaries:

• laminar flow — n. the regular, continuous, smooth movement of a fluid …   English World dictionary

• laminar flow — Hydraul., Mech. the flow of a viscous fluid in which particles of the fluid move in parallel layers, each of which has a constant velocity but is in motion relative to its neighboring layers. [1945 50] * * * Fluid flow in which the fluid travels… …   Universalium

• laminar flow — noun nonturbulent streamline flow in parallel layers (laminae) • Hypernyms: ↑streamline flow * * * noun : streamline flow in a viscous fluid near a solid boundary contrasted with turbulent flow * * * Hydraul., Mech. the flow of a viscous fluid in …   Useful english dictionary

• Laminar-flow — Laminare (an der Zigarette) und turbulente (oben) Strömung am Beispiel des Rauchs einer Zigarette. Die laminare Strömung (lat. lamina „Platte“) ist die Bewegung von Flüssigkeiten und Gasen, bei der keine Turbulenzen… …   Deutsch Wikipedia

• Laminar Flow — Laminare (an der Zigarette) und turbulente (oben) Strömung am Beispiel des Rauchs einer Zigarette. Die laminare Strömung (lat. lamina „Platte“) ist die Bewegung von Flüssigkeiten und Gasen, bei der keine Turbulenzen… …   Deutsch Wikipedia

• laminar flow — laminarusis tekėjimas statusas T sritis fizika atitikmenys: angl. laminar flow; laminated flow; streamline flow vok. laminare Strömung, f; Laminarströmung, f; Schichtenströmung, f rus. ламинарное течение, n; слоистое течение, n pranc. écoulement… …   Fizikos terminų žodynas

• laminar flow — sluoksninis tekėjimas statusas T sritis Standartizacija ir metrologija apibrėžtis Tekėjimas, kai klampos jėgos vyrauja inercijos jėgų atžvilgiu. atitikmenys: angl. laminar flow vok. Laminarbewegung, f; laminare Bewegung, f; laminare Strömung, f;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• laminar flow — sluoksninis tekėjimas statusas T sritis chemija apibrėžtis Skysčio arba dujų tekėjimas tarpusavyje nesimaišančiais plonais sluoksniais. atitikmenys: angl. laminar flow rus. ламинарное течение ryšiai: sinonimas – laminarinis tekėjimas …   Chemijos terminų aiškinamasis žodynas

• laminar flow — laminarinis tekėjimas statusas T sritis Energetika apibrėžtis Skysčio arba dujų tekėjimas tarpusavyje nesimaišančiais plonais sluoksniais. Laminarinis tekėjimas apibūdinamas Reinoldso skaičiumi Re. atitikmenys: angl. laminar flow vok.… …   Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas

• laminar flow —    Flow in which the head loss is proportional to the first power of the velocity [22]. Water flowing in a laminar manner will have streamlines that remain distinct and the flow direction at every point remains unchanged with time.    Synonymous… …   Lexicon of Cave and Karst Terminology

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