Soldato
- Joined
- 13 Mar 2006
- Posts
- 6,712
Trying to match the resistance of water flow between a 1/2"(12.7mm) internal diameter pipe and 10 flattened 15mm diameter tubes with internal diameter of 13.6 mm each running in parallel. I know about Poiseuille's law on resistance being inversely proportional to the radius^4, but can't seem to find out too much about how to work out the resistance in a rectangular or elliptical tube, other than these papers, and my maths is a bit too rusty to make much headway with them:
http://arxiv.org/PS_cache/physics/pdf/0412/0412015v3.pdf
http://www2.mic.dtu.dk/research/mifts/publications/3week/Jun2004HydraulicRes.pdf
The internal perimeter of the tube is going to equal 2pi r or 13.6 pi in mm (~42.7256601mm). I need to work out what dimension rectangle (height x length, with height+width equalling 21.36283mm) will equal a tenth the resistance of a 12.7mm tube.
If anyone can help I will buy you a crate of e-beer.
http://arxiv.org/PS_cache/physics/pdf/0412/0412015v3.pdf
http://www2.mic.dtu.dk/research/mifts/publications/3week/Jun2004HydraulicRes.pdf
The internal perimeter of the tube is going to equal 2pi r or 13.6 pi in mm (~42.7256601mm). I need to work out what dimension rectangle (height x length, with height+width equalling 21.36283mm) will equal a tenth the resistance of a 12.7mm tube.
If anyone can help I will buy you a crate of e-beer.