Not easy to give specific comment without knowing what is being asked about Rn.
However I would not suggest you offer any interpretation of what you think Rn might mean or imply. That way you could open the door to invite other questions that will soon reveal any lack of depth in understanding.
Better in my view to stick to basics to show you are familiar with them. Depending on what you are asked the basics The basics would include such things as:
" Reynolds number is non-dimensional (meaning it is pure number and has no units) and is calculated in the case of an aircraft by mutiplying the density of the air it is in by the speed of the aircraft and multiplying again by the length of the aircraft and dividing the result by the viscosity of the air".
(Which just puts into words R = Density x Speed x Length / Viscosity)
"Reynolds umber is particularly important when comparing results between practical cases. Any large difference in the Reynolds number between cases may invalidate to some extent any comparison - for example in a wind tunnel test the length of the model will be very small compared to that of the real aircraft and it may be beneficial to increase the model Rn by pressurising the tiunnel. This will reduce the so called "Scale Effect" issues of very different Rns".
Wikipedia is helpful where it says
Reynolds numbers frequently arise when performing dimensional analysis of fluid dynamics problems, and as such can be used to determine dynamic similitude between different experimental cases.
They are also used to characterize different flow regimes, such as laminar or turbulent flow: laminar flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion; turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies, vortices and other flow instabilities.
But like I said don't get suckered into conjecturing.
As a last result
" I am familiar with the basics of Rn but I am not sure I quite understand your question"
Last edited by John Farley; 21st August 2012 at 10:39.