{"id":389414,"date":"2024-10-13T20:06:53","date_gmt":"2024-10-13T20:06:53","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-rocky-cfd-dem-semi-resolved-method\/"},"modified":"2024-10-13T20:06:53","modified_gmt":"2024-10-13T20:06:53","slug":"ansys-rocky-cfd-dem-semi-resolved-method","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-rocky-cfd-dem-semi-resolved-method\/","title":{"rendered":"Ansys rocky CFD-DEM semi resolved method"},"content":{"rendered":"<p>&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;I tried to do a cfd-dem coupling with Rocky semi-resolved method and I faced an issue.&nbsp; the PI controller never converges. I have a very fine mesh for my simullation and Im using laminar model. after each iterations all residuals parameters value like continuty goes down but the PI controller fluctuates and goes up and down and never not converges. every thing is in default for PI controller in Rocky. I have also included an image of iterations. I tried to find my answer in cfd coupling manual , but it does not mention anything about pi controller.&nbsp;&lt;\/p&gt;&lt;p&gt;Can you please help me find a way for the convergence ?&lt;\/p&gt;&lt;p&gt;Thanks&nbsp;&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/09\/19-09-2024-1726789362-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/13-10-2024-1728849898-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-389414","topic","type-topic","status-publish","hentry","topic-tag-cfd-dem","topic-tag-rocky-dem-1"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Hello, I tried to do a cfd-dem coupling with Rocky semi-resolved method and I faced an issue. the PI controller never converges. 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