{"id":161649,"date":"2023-01-25T07:16:34","date_gmt":"2023-01-25T07:16:34","guid":{"rendered":"\/knowledge\/forums\/topic\/if-ks0-its-a-smooth-surface-but-the-default-value-for-cs-0-5-which-represents-a-uniform-sand-grain-roughness-so-is-the-surface-smooth-surface-or-sand-grain-surface\/"},"modified":"2023-07-31T12:35:38","modified_gmt":"2023-07-31T12:35:38","slug":"if-ks0-its-a-smooth-surface-but-the-default-value-for-cs-0-5-which-represents-a-uniform-sand-grain-roughness-so-is-the-surface-smooth-surface-or-sand-grain-surface","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/if-ks0-its-a-smooth-surface-but-the-default-value-for-cs-0-5-which-represents-a-uniform-sand-grain-roughness-so-is-the-surface-smooth-surface-or-sand-grain-surface\/","title":{"rendered":"If Ks=0, it’s a smooth surface, but the default value for Cs = 0.5, which represents a uniform sand-grain roughness. So, is the surface smooth surface or sand-grain surface?"},"content":{"rendered":"

If Ks = 0 then there is no surface roughness and it becomes a smooth wall. If you want to provide a roughness height, you can do that directly changing the value of Ks. If the sand grain roughness is uniform, then you don’t need to change the Cs value from default (0.5). But if the roughness is not uniform then you might have to play around with the Cs values as well.<\/p>\n","protected":false},"template":"","class_list":["post-161649","topic","type-topic","status-publish","hentry","topic-tag-17-2","topic-tag-fluent","topic-tag-fluid-dynamics","topic-tag-general","topic-tag-general-fluent"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t