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Reynolds number for clean cold water flow.
Turbulent or laminar flow is determined by the dimensionless
Reynolds Number which is important when analyzing fluid flow where there is a substantial velocity gradient (i.e. shear). The Reynolds number indicates the relative significance of the viscous effect compared to the inertia effect and the number is proportional to the inertial force divided by the viscous force.
The flow is
laminar when Re < 2300
transient when 2300 < Re < 4000
turbulent when 4000 < Re
Reynolds Number for one liter of water at approximately
20 flowing through pipes of different dimensions: oC (68 oF)
Water Flow in Tubes - Reynolds Number
(inches) 1 1 1/2 2 3 4 6 8 10 12 18
(mm) 25 40 50 75 100 150 200 250 300 450
Reynolds number with
1 liter/min 835
Reynolds number with
1 gal/min 3180
Note that the
water viscosity varies with temperature.
the kinematic viscosity of water at
20 - used to calculate the table above - is oC 1.004·10 -6 m 2/s at
0 the kinematic viscosity is oC 1.787·10 - the Reynolds values in the table above must be multiplicated with -6 m 2/s 1.004 / 1.787 = 0.56 at
100 the kinematic viscosity is oC 0.29·10 - the values in the table above must be multiplicated with -6 m 2/s 1.004 / 0.29 = 3.46
Pipe lines - fluid flow and pressure loss - water, sewer, steel pipes, pvc pipes, copper tubes and more.
The study of fluids - liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time.
Water flow and pressure loss
(psi/ft) due to friction in copper tubes ASTM B88 Types K, L and M.
Calculate hydraulic diameter for pipes and ducts.
Friction head loss (
ft) in water pipes can be estimated with the empirical Hazen-Williams equation. H2O per 100 ft pipe
Pressure loss in hoses due to water flow and friction.
Heat transfer, pressure and head loss in a fluid varies with laminar, transitional or turbulent flow.
Kinematic viscosities of some common liquids like motor oil, diesel fuel, peanut oil and many more.
Calculate fluid velocity and volume flow in pipes and tubes.
Introduction and definition of the dimensionless Reynolds Number - online calculators.
Maximum water flow capacities in steel pipes - pipe dimensions ranging
2 - 24 inches.
Absolute viscosity for water in centipoises for temperatures between
32 - 200. oF
Recommended maximum flow velocities in water systems on the delivery side of the pump.
Free online tool for designing water supply systems in buildings.
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