small vortex generators in tube?
small vortex generators in tube?
(OP)
How would one calculate what size and how far apart to machine some small votex generators(basically slits) in a 8" dia tueb with water moving through it at 120 mph. The thinking here is that there is some drag that can be decreadsed by creating a boundry layer on the edges. Would this not make the tube act as a smaller diameter thus decreasing volume?





RE: small vortex generators in tube?
RE: small vortex generators in tube?
RE: small vortex generators in tube?
RE: small vortex generators in tube?
but it's not clear just waht you hope to achieve by this ...
a) limit the flow through the tube ? (sounds like you think a thicker BL is what you want)
b) maximise flow in the tube ?
is this s single phase problem ? ie how much dissolved gas in the water ? will it separate out (cavitate) ?
is the tube is completely immersed in water (on both sides of the wall) ?
what do you think the slits on the SS fighter do for it ? how can you apply this to your problem ?
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RE: small vortex generators in tube?
Mike Halloran
Pembroke Pines, FL, USA
RE: small vortex generators in tube?
it sounds like you're trying to increase either the volume flow rate or the pressure recovery of your tube. trying to reduce surface drag, playing with the boundary layer Might Just improve things. The Only point to doing this is that you've calc'd that this tweek will get your where you want to be.
so, what's the problem ? is it flow rtae or pressure recovery (those could be different descriptions of the same problem) ?
how far out of bed are you ?
how long is the pipe ?
slits ?? is the pipe immersed in water ? is this like the intake on a personal watercraft ? if you had slits, which way would the water flow (into or out of the tube) ?
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RE: small vortex generators in tube?
RE: small vortex generators in tube?
are you not getting the required flow ?
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RE: small vortex generators in tube?
RE: small vortex generators in tube?
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RE: small vortex generators in tube?
RE: small vortex generators in tube?
if you can't access the tape (and "copy" it), can you do CFD ? i wouldn't trust the results without a test but they should get you some way along the path. if you can't do CFD then you're stuck with testing things. if you don't want to do this, see the previous post about using a bigger tube. i doubt that there is a canned solution for your problem.
again, how much are you trying to gain ? is the power required 2* what you want ? 1.1* ??
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RE: small vortex generators in tube?
RE: small vortex generators in tube?