calc_Re¶

pychemengg.heattransfer.heatcommonmethods.calc_Re(characteristic_length=None, velocity=None, density=None, viscosity=None)[source]¶

To compute Reynolds number for flowing fluid.

Parameters

characteristic_lengthint or float: Relevant length for computing Reynolds number (see Notes).
velocityint or float: Velocity of fluid.
densityint or float: Density of fluid.
viscosityint or float: Viscosity of fluid.

Returns

Reynolds numberint or float: Reynolds number for a flowing fluid.

Notes

The following formula is used:

\[Re = \frac {L_c V \rho} {\mu}\]

where:

\(L_c\) = characteristic length

for example:
\(L_c\) = internal diameter of pipe/tube for fluid flowing in a circular tube/pipe \(L_c\) = external diameter for fluid flowing outside a circular tube/pipe \(L_c\) = hydraulic diameter for fluid flowing in a non-circular tube/pipe

V = fluid velocity

\(\rho\) = density of fluid

\(\mu\) = viscosity of fluid

References

[1] G. F. Nellis and S. A. Klein, “Introduction to Engineering Heat Transfer”, 1st Edition. Cambridge University Press, 2021.

[2] Y. A. Cengel and A. J. Ghajar, “Heat And Mass Transfer Fundamentals and Applications”, 6th Edition. New York, McGraw Hill Education, 2020.

[3] T.L. Bergman, A. S. Lavine, F. P. Incropera, D. P. Dewitt, “Fundamentals of Heat and Mass Transfer”, 7th Edition, John Wiley, 2011.

Examples

First import the module heatcommonmethods.

>>> from pychemengg.heattransfer import heatcommonmethods as hcm 
>>> hcm.calc_Re(characteristic_length=0.015, velocity=6.43,
                density=1.059, viscosity=2.008e-5)
5086.680776892429