Talk:Laminar flow

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Picture of a submarine The picture of the submarine shows not laminar flow as stated in the description of the picture. The flow is only laminar for the first few centimeter from the leading edge of the submarine, assuming a critical Reynoldsnumber of 10000, and normal viscosity of water.

It certainly appears to be laminar for several feet. Perhaps microturbulence does start earlier on, but only reaches a visible level when the bubbles appear in the water. StuRat 05:25, 14 June 2006 (UTC)
The flow arround the front of the sub shows very little deformation of the water surface, thus one might think that the flow is laminar, but at high Reynoldsnumbers like for flow arround a submarine, flow is always turbulent. Think of a river surface without wind, the watersurface appears flat, but the flow is actually turbulent. Also, the braking of the wave, causing the white spray has very little to do with the turbulence, as one might think from the description of the picture. The word microturbulence is misleading since the instability phenomenons causing turbulence are responsible firstly for the big scale turbulence, which is then transfered via mediumscale and microscale turbulence to the fluid viscosity. Gudo 14 June 2006 (UTC)

Inviscid flow[edit]

I am under the impression that inviscid flow is non-laminar. I think the point about inviscid flow should be changed to a point about creeping motion (Stokes flow) which is the exact opposite of inviscid flow - viscous effects are much greater than inertial effects. Any thoughts? Easyl 15:05, 12 January 2007 (UTC)

I will go ahead and make the change Easyl 11:43, 23 January 2007 (UTC)

Reynolds Number[edit]

This article says Laminar flow occurs when the Reynolds number is < 2040, but the Reynolds number article says Laminar flow occurs when Re < 2300. Which is correct? — Preceding unsigned comment added by Bungeh (talkcontribs) 03:24, 18 September 2012 (UTC)

The two are almost the same. Reynolds numbers shown on diagrams are usually shown on a logarithmic scale. The logarithm of 2040 is almost the same as the logarithm of 2300. Also, Reynolds number is used in numerous different applications - internal diameter of a pipe; distance along a pipe; chord of an airfoil; span of a wing etc.Dolphin (t) 22:44, 30 May 2015 (UTC)

Request photo[edit]

I appreciate the diagrams; however, I wonder if you can please provide a picture of what a laminar jet of water looks like also? (talk) 20:27, 26 December 2012 (UTC)

Article lacks history section[edit]

This article would benefit from a history section to describe the chronological development of our understanding of laminar flow and the people responsible. FreeFlow99 (talk) 12:12, 31 December 2012 (UTC)

More than just velocity[edit]

the article made it sound like laminar/turbulent flow depended only on velocity but according to this it also depends on viscocity: — Preceding unsigned comment added by (talk) 06:33, 29 May 2015 (UTC)

Whether the flow in a flow field will be laminar or turbulent can be anticipated with some reliability by taking account of the Reynolds number. The Reynolds number is based on a representative speed, a characteristic length and the kinematic viscosity of the fluid. Alternatively, if the Reynolds number is based on the dynamic viscosity of the fluid, then the density of the fluid is also significant. Dolphin (t) 01:45, 30 May 2015 (UTC)