Yplus in compressible solvers

dinonettis · April 29, 2008, 07:18

Hi everybody,

could somebody tell me how to calculate the Yplus in compressible solvers, please? I've tried to use checkYplus but it needs the file transportproperties that is present only in incompressible solvers....
Thank you in advance,

dino

camoesas · September 26, 2011, 07:43

HI Everybody,

I am also interested in an utility for calculating Yplus with compressible solver? Isn't there anything?

Thanks

Camoesas

gooya_mehdy · September 26, 2011, 16:36

Hi All, I have the same problem

, could you please answer the question?!
thanks a lot

camoesas · October 4, 2011, 04:57

really no possibility??

florian_krause · October 4, 2011, 05:23

In case you are using RANS, did you try the yPlusRAS utility with the -compressible option?

Florian

camoesas · October 4, 2011, 11:07

HI Florian,

Thanks for your hint!
Yeah its working for rhoSimpleFoam! But not for buoyantSimpleFoam. Do you know where I have to check whether y+ or y* is implemented?
( I have read in some threads that in former versions they have implemented y* instead of y+)

Thanks Camoesas

florian_krause · October 4, 2011, 11:57

OK I should have said in my first post that I never used any compressible solvers in OF, so I am not sure of how much help I am...

Anyway, yPlusRAS with -compressible option needs a rho field (which makes sense, if you think about the definition of the dimensionless wall distance y+ (compressible)). I've just checked that for the OF-1.7.x tutorial buoyantSimpleFoam/buoyantCavity and there is no rho field written out...

What exactly do you mean by y* (defintion)?

Best,
Florian

camoesas · October 6, 2011, 06:51

HI Florian,

Yes there´s no rho in time folders, but there´s neither a 'transportProperties' in constant folder. (for buoyantSimpleFoam)

As I know the definition of y* is:

y* = y * u_delta / delta_1 / u_tau

y* := ystar
y := wall distance
u_delta := velocity at outer edge of boundary layer
delta_1 := displacement thickness
u_tau := sqrt ( wallShearStress / rho)

camoesas

April 29, 2008, 07:18	Hi everybody, could somebod	#1
dinonettis Member Leonardo Nettis Join Date: Mar 2009 Posts: 72 Rep Power: 17	Hi everybody, could somebody tell me how to calculate the Yplus in compressible solvers, please? I've tried to use checkYplus but it needs the file transportproperties that is present only in incompressible solvers.... Thank you in advance, dino

September 26, 2011, 16:36		#3
gooya_mehdy New Member mehdy Join Date: May 2011 Posts: 5 Rep Power: 15	Hi All, I have the same problem, could you please answer the question?! thanks a lot

October 4, 2011, 11:57		#7
florian_krause Senior Member Florian Krause Join Date: Mar 2009 Location: Munich Posts: 103 Rep Power: 17	OK I should have said in my first post that I never used any compressible solvers in OF, so I am not sure of how much help I am... Anyway, yPlusRAS with -compressible option needs a rho field (which makes sense, if you think about the definition of the dimensionless wall distance y+ (compressible)). I've just checked that for the OF-1.7.x tutorial buoyantSimpleFoam/buoyantCavity and there is no rho field written out... What exactly do you mean by y* (defintion)? Best, Florian Last edited by florian_krause; October 4, 2011 at 12:06. Reason: specified which y+ (compressible)

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September 26, 2011, 07:43		#2
camoesas Senior Member Join Date: Mar 2009 Posts: 138 Rep Power: 17	HI Everybody, I am also interested in an utility for calculating Yplus with compressible solver? Isn't there anything? Thanks Camoesas

October 4, 2011, 04:57		#4
camoesas Senior Member Join Date: Mar 2009 Posts: 138 Rep Power: 17	really no possibility??

October 4, 2011, 05:23		#5
florian_krause Senior Member Florian Krause Join Date: Mar 2009 Location: Munich Posts: 103 Rep Power: 17	In case you are using RANS, did you try the yPlusRAS utility with the -compressible option? Florian

October 4, 2011, 11:07		#6
camoesas Senior Member Join Date: Mar 2009 Posts: 138 Rep Power: 17	HI Florian, Thanks for your hint! Yeah its working for rhoSimpleFoam! But not for buoyantSimpleFoam. Do you know where I have to check whether y+ or y* is implemented? ( I have read in some threads that in former versions they have implemented y* instead of y+) Thanks Camoesas

October 6, 2011, 06:51		#8
camoesas Senior Member Join Date: Mar 2009 Posts: 138 Rep Power: 17	HI Florian, Yes there´s no rho in time folders, but there´s neither a 'transportProperties' in constant folder. (for buoyantSimpleFoam) As I know the definition of y* is: y* = y * u_delta / delta_1 / u_tau y* := ystar y := wall distance u_delta := velocity at outer edge of boundary layer delta_1 := displacement thickness u_tau := sqrt ( wallShearStress / rho) camoesas