Re: [ESPResSo-users] flow profile square duct - deviation

[Wink, Markus]

Hello,

 

I used the formula which can be found attached to that email. For the series expansion I have used the first 17 entries.

 

I have just realized, that I did not really described, what I have done in the simulation, sorry about that:

I simulated a LB-fluid inside a square duct. The fluid consists of water, agrid is set to 1. Furthermore a constant force density is applied to the fluid nodes.

 

Still wondering about the deviation

 

Greetings

 

Markus

 

 

Von: Abdallah Daddi Moussa Ider [mailto:address@hidden
Gesendet: Dienstag, 20. Januar 2015 15:06
An: Wink, Markus
Betreff: Re: [ESPResSo-users] flow profile square duct - deviation

 

Dear Markus,

Did you use the celebrated solution of Spiga and Morini (1994) for your comparison? (See the the equations (13)-(17) in this pdf)

https://lirias.kuleuven.be/bitstream/123456789/288459/1/0673-en.pdf

bests
a

 

 

On Tue, Jan 20, 2015 at 11:46 AM, Wink, Markus <address@hidden> wrote:

Hello everybody,

 

I performed a simple simulation of a poiseuille flow in a microfluidic square duct. I wanted to check, whether the simulated profile matches with the theoretical one (I found the formula in frank M. White’s “Viscous Fluid Flow”).

 

The simulated values matches the theoretical ones quite good in the middle of the channel. Strangely enough, I have a quite big deviation close to walls of the channel (the last fluid node closest to the boundary nodes), which is even worse in the corners of the channel (about 42% deviation (!!) ). I was wondering, where this deviation comes from. Attached you will find the simulation script as well as the plots showing the deviation.

 

Does anyone have a clue, where the deviation comes from?

 

Greetings

 

Markus

 

 

 

rect_duct_flow_profile.pdf
Description: rect_duct_flow_profile.pdf