{"id":397142,"date":"2024-12-11T17:38:51","date_gmt":"2024-12-11T17:38:51","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/coarse-graining-in-rocky\/"},"modified":"2024-12-11T17:38:51","modified_gmt":"2024-12-11T17:38:51","slug":"coarse-graining-in-rocky","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/coarse-graining-in-rocky\/","title":{"rendered":"Coarse graining in Rocky"},"content":{"rendered":"<p>&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;1-I wanted to use coarse graining for a CFD-DEM simulation. since in cfd-dem the size of particle should be smaller than CFD cell size and the CGM scale factor is multiplying the size of the particle (particle dimension) , I should be careful that the size of the particle do not get larger than the CFD cell size after multiplied by the CGM scale factor or the size of the original particle should be smaller than CFD cell size ?&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;2- I did simulations with different porosity using CFD-DEM, the porosity was 0, 0.2, 0.6 and I my results for 0.6 are not very good. what could be the reason and how can I improve it? all parameters are same for all simulations.&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-397142","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,1-I wanted to use coarse graining for a CFD-DEM simulation. since in cfd-dem the size of particle should be smaller than CFD cell size and the CGM scale factor is multiplying the size of the particle (particle dimension) , I should be careful that the size of the particle do not get larger than the\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" 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