Question

The Reynolds number for a fluid with density d, free-stream velocity V, viscosity u at a distance x from the leading edge is_____

(a) R = \(\frac {Vd}{ux}\)

(b) R = \(\frac {xVd}{u}\)

(c) R = \(\frac {Vx}{dx}\)

(d) R = \(\frac {xdu}{V}\)

This question was posed to me in a job interview.

The question is from Laminar Flow topic in portion Incompressible Flow over Airfoils of Aerodynamics

Answer 1

Right option is (b) R = \(\frac {xVd}{u}\)

The explanation is: Reynolds number is an important quantity in the study of fluid dynamics and aerodynamics. The correct formula is R = \(\frac {xVd}{u}\). It is important to remember that it is a dimensionless quantity.