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MLA January 1, 2009 12:57

laminar flow in circular pipe
 
Hey! I'm looking for a test case to verify my code. I used FVM(fortran code) to simulate a laminar flow in pipe can any one help or send me a paper? Thanks in advance

otd January 1, 2009 19:25

Re: laminar flow in circular pipe
 
Hagen-Poiseuille flow through a pipe for flow downstream of the inlet section. The flow is independent of z there (at least until turbulence sets in). The axial velocity is parabolic, w(r, z), where r is the radial coordinate. Use mass converation to learn that the CL axial velocity is 1.5 x the average axial velocity. My old version of Schlichting (Boundary Layer Theory) has it all worked out.

For the entrance region flow, find some data (friction factors?). Compare the CL axial velocity w(r = 0, z) from your calculation with the data.

MLA January 3, 2009 12:41

Re: laminar flow in circular pipe
 
dear otd thanks for your message.but there is a little problem in parabolic velocity i.e. the coeficient is depend on pressure drop which is unknown befor solving the problem! as you know the inlet and outlet bc's are velocity inlet and prresure outlet .thanks again

versi January 3, 2009 23:06

Re: laminar flow in circular pipe
 
The pressure drop may be given a-priori.

Inlet BC: Pressure = given, u-component = extrapolated according to du/dx=0, v-component =0,

Outlet BC: pressure =0.0, d(u,v)/dx=0


Goutam June 27, 2012 09:53

Quote:

Originally Posted by MLA
;58387
Hey! I'm looking for a test case to verify my code. I used FVM(fortran code) to simulate a laminar flow in pipe can any one help or send me a paper? Thanks in advance

Hi, Did you find a paper? Could you please email me the paper, I am using FVM (fortran code) to simulate a laminar flow in pipe. Could you please answer my following questions:

Also, how I will calculate the inlet and outlet pressure? I have used parabolic velocity profile and my velocity and pressure graph looks correct.

Also, how I will calculate the Nusselt number? (Looking for a fortran code)

Thanks for your time.

Goutam

cdegroot July 1, 2012 17:55

Quote:

Originally Posted by Goutam (Post 368582)
Hi, Did you find a paper? Could you please email me the paper, I am using FVM (fortran code) to simulate a laminar flow in pipe. Could you please answer my following questions:

Also, how I will calculate the inlet and outlet pressure? I have used parabolic velocity profile and my velocity and pressure graph looks correct.

Also, how I will calculate the Nusselt number? (Looking for a fortran code)

Thanks for your time.

Goutam

Hi. You don't need a paper. Just check any basic fluid mechanics textbook and you will find a formula for dp/dx (or derive it quite easily). Since dp/dx is constant, the pressure profile is a line. Assuming you specified an outlet pressure you can find the correct pressure anywhere else.

Goutam July 2, 2012 07:11

Quote:

Originally Posted by cdegroot (Post 369152)
Hi. You don't need a paper. Just check any basic fluid mechanics textbook and you will find a formula for dp/dx (or derive it quite easily). Since dp/dx is constant, the pressure profile is a line. Assuming you specified an outlet pressure you can find the correct pressure anywhere else.

Hi

For my case, I use water as fluid for laminar pipe flow problem. I found that flow is fully developed from inlet to outlet since I used parabolic velocity profile at the inlet. Also pressure is decreasing from inlet to outlet. Problem is my pressure drop profile is not linear and I calculated the friction factor which is not good at all. (Analytical result: f = 64/Re). But my velocity profile is fully correct. But when I use air as a fluid, then all my results were correct.

Thanks

Goutam July 3, 2012 13:06

My problem is solved and I am now getting the correct pressure drop results. Only problem remains is the Nusselt number !!!!!!!!!


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