The division of Reynolds number for flow around airfoil
 

I’m working on the flow around the oscillating foils, in which the fluid is water. I found lots of posts include the terms “low Reynolds number” “high Reynolds number”. But none of them give the absolute range for these terms.

That’s what I’m confused.

So for the problem of flow around a NACA foil, which range of Reynolds number can be called low Re? Which range Reynolds number can be called high Re? And which range can be called medium Reynolds number?

Thank you.

Low and high are subjective and relative. If they don't mention any specific number referring to a specific flow situation then there is no meaning to it. This is not a Starbucks or fast food restaurant where you have small, medium, and large sized servings.

Thank you for your reply.

You are definitely right. I found such idea in other posts.