Flow Rate through Convoluted vs Smooth Bore Hose 1

[Chairs]

Can someone explain the difference in flow rates and pressure differences between convoluted and smooth bore hoses? Smooth bore is pretty straight forward but I'm having trouble finding information about convoluted hoses. I assume there would be a pressure drop and a non uniform flow but I can't find any good explanations. I'm using air as my media. Thanks

 

[bimr]

The corrugation is the same as pipe roughness. The fluid travels along the wall, the corrugation increases the turbulence which increases the drag.

The resistance of a particular hose will depend on the fashion in which it is constructed. You would have to get that from the manufacturer.

Here are some examples. Common Friction Factor Values of C hw used for design purposes are:

Asbestos Cement 140
Brass tube 130
Cast-Iron tube 100
Concrete tube 110
Copper tube 130
Corrugated steel tube 60
Galvanized tubing 120
Glass tube 130
Lead piping 130
Plastic pipe 140
PVC pipe 150
General smooth pipes 140
Steel pipe 120
Steel riveted pipes 100
Tar coated cast iron tube 100
Tin tubing130
Wood Stave 110

 

[Compositepro]

Evenly spaced corrugations often create a series of eddies that tremendously increase the flow resistance of the hose and can turn the hose into a loud siren. I'm sure it's been studied but the math would be pretty complicated and depend on a number of poorly controlled variables. Convoluted hose manufacturers should have empirical data.

 

[Latexman]

Attached is an old correlation I have used for years. Be careful, it yields a Fanning friction factor!

Good luck,
Latexman

 

[katmar]

See also post by vzeos in

http://www.eng-tips.com/viewthread.cfm?qid=212758

Katmar Software - AioFlo Pipe Hydraulics

http://katmarsoftware.com

"An undefined problem has an infinite number of solutions"