Possible to create laminar flow in fast moving air?

[Swamp Thing]

Is it possible to create (nearly?) laminar flow in a tube with rectangular C.S. , around 1 cm X 5 cm , with air moving at around 100 to 150 m/sec?

Turbulence will likely set in sooner or later, but can the laminar flow be made to last over say 20 cm?

 

[Chestermiller]

Is it possible to create (nearly?) laminar flow in a tube with rectangular C.S. , around 1 cm X 5 cm , with air moving at around 100 to 150 m/sec?

Turbulence will likely set in sooner or later, but can the laminar flow be made to last over say 20 cm?

What is your assessment of this so far?

 

[Swamp Thing]

When I posted, I had got a Reynolds number around 7000. So I was wondering if it would work if we used a sheaf of soda straws or something to laminarize the flow.

But I have since found errors in my calculation -- the RN is actually like 260,000. So it's probably not doable, I'm thinking.

 

[Chestermiller]

When I posted, I had got a Reynolds number around 7000. So I was wondering if it would work if we used a sheaf of soda straws or something to laminarize the flow.

But I have since found errors in my calculation -- the RN is actually like 260,000. So it's probably not doable, I'm thinking.

I agree.

 

[boneh3ad]

It will still be laminar over some small distance near the entrance. The question is how small.