Wall Shear Stress calculation

DudaAPD · October 23, 2014, 08:56

Hi all,

I want to have the total wall shear stress (WSS). Fluent will give me the WSS area-weighted for each fluid: gas and liquid. Would it be correct to sum the WSS given from fluent for the liquid and the gas? ( WSS_l + WSS_g = WSS_total)?

I can't find anywhere saying how the WSS is calculated by Fluent, hence I don't know if the volume fractions are being used or how the perimeter is used for each phase.

Thanks in advance for the help!

black key · October 26, 2014, 02:15

Calculate the wall shear stress from Forces in Reports.
This will give you the pressure force and the viscous force. This will be the total viscous force of the two liquids.

DudaAPD · October 27, 2014, 12:21

Thank you Black Key. It is actually ok to do as I did. I´ve compared with the viscous force at the wall as you said, and it was good.

October 23, 2014, 08:56	Wall Shear Stress calculation	#1
DudaAPD New Member Luiz Eduardo Join Date: May 2010 Posts: 19 Rep Power: 16	Hi all, I want to have the total wall shear stress (WSS). Fluent will give me the WSS area-weighted for each fluid: gas and liquid. Would it be correct to sum the WSS given from fluent for the liquid and the gas? ( WSS_l + WSS_g = WSS_total)? I can't find anywhere saying how the WSS is calculated by Fluent, hence I don't know if the volume fractions are being used or how the perimeter is used for each phase. Thanks in advance for the help!

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October 26, 2014, 02:15		#2
black key New Member Join Date: Nov 2012 Posts: 4 Rep Power: 14	Calculate the wall shear stress from Forces in Reports. This will give you the pressure force and the viscous force. This will be the total viscous force of the two liquids.

October 27, 2014, 12:21		#3
DudaAPD New Member Luiz Eduardo Join Date: May 2010 Posts: 19 Rep Power: 16	Thank you Black Key. It is actually ok to do as I did. I´ve compared with the viscous force at the wall as you said, and it was good.