{"id":431259,"date":"2025-05-10T19:54:03","date_gmt":"2025-05-10T19:54:03","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/strain-rateshear-stress-at-the-interface-in-vof-simulations\/"},"modified":"2025-05-10T19:54:03","modified_gmt":"2025-05-10T19:54:03","slug":"strain-rateshear-stress-at-the-interface-in-vof-simulations","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/strain-rateshear-stress-at-the-interface-in-vof-simulations\/","title":{"rendered":"Strain rate\/Shear stress at the interface in VoF simulations"},"content":{"rendered":"<p>&lt;p&gt;Hi&lt;\/p&gt;&lt;p&gt;I have run a 3D air-water pipe flow simulation where the water free surface is about 50% filling the pipe diameter. I want to calculate the shear stress applied by the air on the water interface. For that i have turned on the strain rate in Fluent post-proc. After that i have multiplied by the total viscosity to get the shear stress at the interface. But i am confused which shear stress value it is? Or which strain rate is acting on the interface? Is it only air or only water or because of both air and water? I want the shear applied by air on water surface only. How can i get that?&lt;\/p&gt;&lt;p&gt;any help is appreciated..thanks&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-431259","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"HiI have run a 3D air-water pipe flow simulation where the water free surface is about 50% filling the pipe diameter. I want to calculate the shear stress applied by the air on the water interface. For that i have turned on the strain rate in Fluent post-proc. 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