It's the best joke I ever...Thanks. Tell me in return - what is the law K44?
Reynolds number (Rn) is defined as Rn=(ρVL)/μ=(VL)/ν, where V is the fluid velocity relative to the body and L is a typical length.
So by this definition Reynolds number is directly related with velocity and length.
for floating body or partly submerged body it more appropriate to use Froud Number in similarity studies or dimensional analysis.
Hi Osagie and all.
In this case the Reynolds number should be defined using the relative velocity between ship and water. When the water itself is also allowed to move (sea currents, up/down a river etc.), and this is a common situation, what realy determines the drag force exerted by the water on the ship, is the relative velocity between them. For the simplest situation, say, sailing in a still lake, the gap in your proposed sentence should be filled with “directly proportional”.
Also, the shape we should forget no, sir Peçanha, since a rough ball flies better that perfect one. Regards. Very nice question-joke, isn't it.
Hi Dmitry and all.
True, but Osagie’s question regarded Reynolds number only. Also, for a given sphere diameter, the lower Reynolds is, the less important is the sphere surface rugosity regarding the drag force.
That's right, dear R.T. Reynolds number doesn't have a relation to drag resistance and a ship directly. But the ship, in the discussion context, confuses: let it be the same sizes and the relative velocity but different shapes: though Reynolds is the same but there is no pragmatic for NAVY.
Osagie, if you wish to solve your problem, disregard all the "advises" and keep in mind: The Re is a function of the ship speed, the viscosity and its length measured on the water plane. Take all the other opinions at ease.
The viscosity is discipline in fluid Army. When it falls, disorder comes - mother the Anarchy. So, I prefer high Reynolds numbers.
Hi Dmitry and all.
It’s a nice analogy that between viscosity and the Army discipline. I haven’t heard of it. Well, … discipline means order, isn’t it? Then, what about relating viscosity and entropy, a quantity that increases with disorder and is directly proportional to the reversible heat exchanged between material bodies (fluid particles?) and inversely proportional to their absolute temperature? Someone must have thought of it by now! Who would be the sergeant keeping the battalion order? Model it!
It was, Dear @R. P. Peçanha , just an interpretation of words Reynolds had said during a lecture long-long ago, his finding - not mine.
When I was a student I've drew a poster with Reynolds portrait and his quotation, and wrote "remember that old Reynolds said, don't forget up to examines, but after that you can get it away from your mind as a bad dream" .
Dmitry, wouldn't be for you to have a good calming (samovar prepared) tea instead of talking to us about the fluid Army?
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