# Fully developed flow and convergance

 Register Blogs Members List Search Today's Posts Mark Forums Read

 September 10, 2019, 14:17 Fully developed flow and convergance #1 Member   Soumitra Vadnerkar Join Date: Aug 2018 Posts: 70 Rep Power: 7 What is connection between a fully developed flow and its convergence? Can I say, in case of simple flow through pipe scenario, a converged steady state solution would always yield a fully developed flow at the outlet? Also do you think the attached image of velocity contour can represent a fully developed flow till the time it reaches the outlet? https://postimg.cc/Dmf1r3hb

September 10, 2019, 15:33
#2
Super Moderator

Alex
Join Date: Jun 2012
Location: Germany
Posts: 3,406
Rep Power: 48
Quote:
 Can I say, in case of simple flow through pipe scenario, a converged steady state solution would always yield a fully developed flow at the outlet?
A converged solution does not imply fully developed flow. Flow "development" depends on flow length (i.e. distance of outlet from the inlet) and Reynolds number.
So if the computational domain is not long enough for the flow to be fully developed, you won't get a fully developed flow at the outlet, no matter how good the numerical convergence is. Unless of course you prescribed fully developed conditions at the inlet
The easy way to ensure a fully developed flow would be periodic boundary conditions.

 September 11, 2019, 09:23 #3 New Member   Join Date: Jan 2015 Posts: 19 Rep Power: 11 "Fully developed" is a property of a physical flow at hand while "convergence" is a property of a numerical solution. The two have literally nothing to do with each other.

September 11, 2019, 09:50
#4
Member

Join Date: Aug 2018
Posts: 70
Rep Power: 7
Quote:
 Originally Posted by el_mojito "Fully developed" is a property of a physical flow at hand while "convergence" is a property of a numerical solution. The two have literally nothing to do with each other.
Yeah but, I thought that as velocity profile does not change further, it might be helping for convergence.

 Tags convergance, fully developed flow, velocity profile