Developed turbulent boundary layer simulation on flat plate

Turbulent · June 8, 2015, 06:50

Hello,

I'm doing a RANS simulation of a developed turbulent boundary layer on a 3-D flat plate. I've assumed a certain thickness for the BL at the inflow and correspondingly defined the inflow velocity profile.

My question is how can I define a pre-calculated shear stress only at x=0 (to simulate a certain shear stress at a given location of developed BL) while the rest of the plate will remain as no-slip wall. Avoiding this will cause a jump in the shear stress near the LE just like in normal BL development.

Thanks,

Jack

ghorrocks · June 8, 2015, 07:30

You could make a separate wall boundary for the first element which you define as a slip wall (or a wall with a defined wall shear stress if you prefer). Then the rest of the wall can be a normal wall boundary condition.

Turbulent · June 8, 2015, 12:41

Hi Glenn,

I've tried your suggestion but it seems that specifying pre-defined shear on the first cell stripe did not helped much... there's still a jump in the shear stresses distribution near the LE and the solution was poorly converged. What do you think?

Thanks,
Jack

ghorrocks · June 8, 2015, 20:46

First of all, check your simulation accuracy: Mesh, convergence, time step, etc. Unless they are under control anything could happen.

Assuming they are under control: I would compare the fully developed BL you have generated to one which CFX generates with a simulation. Are they the same?

June 8, 2015, 06:50	Developed turbulent boundary layer simulation on flat plate	#1
Turbulent New Member Jack B. Join Date: Apr 2009 Posts: 24 Rep Power: 18	Hello, I'm doing a RANS simulation of a developed turbulent boundary layer on a 3-D flat plate. I've assumed a certain thickness for the BL at the inflow and correspondingly defined the inflow velocity profile. My question is how can I define a pre-calculated shear stress only at x=0 (to simulate a certain shear stress at a given location of developed BL) while the rest of the plate will remain as no-slip wall. Avoiding this will cause a jump in the shear stress near the LE just like in normal BL development. Thanks, Jack

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Stripes in the boundary layer - Turbulent flat plate tutorials	Jrmy	SU2	1	July 17, 2014 11:48
Turbulent Boundary Layer on a Flat Plate	Hoshang Garda	FLUENT	1	November 27, 2013 11:24
Question about heat transfer coefficient setting for CFX	Anna Tian	CFX	1	June 16, 2013 07:28
Validating OF, turbulent flow over flat plate	Thilo	OpenFOAM Verification & Validation	0	July 3, 2012 06:29
flat plate boundary layer data	Ekachai Juntasaro	Main CFD Forum	3	March 14, 2001 00:18

June 8, 2015, 07:30		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 18,011 Rep Power: 146	You could make a separate wall boundary for the first element which you define as a slip wall (or a wall with a defined wall shear stress if you prefer). Then the rest of the wall can be a normal wall boundary condition.

June 8, 2015, 12:41		#3
Turbulent New Member Jack B. Join Date: Apr 2009 Posts: 24 Rep Power: 18	Hi Glenn, I've tried your suggestion but it seems that specifying pre-defined shear on the first cell stripe did not helped much... there's still a jump in the shear stresses distribution near the LE and the solution was poorly converged. What do you think? Thanks, Jack

June 8, 2015, 20:46		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 18,011 Rep Power: 146	First of all, check your simulation accuracy: Mesh, convergence, time step, etc. Unless they are under control anything could happen. Assuming they are under control: I would compare the fully developed BL you have generated to one which CFX generates with a simulation. Are they the same?