{"id":296720,"date":"2023-08-03T09:41:14","date_gmt":"2023-08-03T09:41:14","guid":{"rendered":"\/forum\/forums\/topic\/ansys-fluent-vs-cfx-dpm-particle-track\/"},"modified":"2023-08-03T09:41:14","modified_gmt":"2023-08-03T09:41:14","slug":"ansys-fluent-vs-cfx-dpm-particle-track","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-fluent-vs-cfx-dpm-particle-track\/","title":{"rendered":"Ansys Fluent vs CFX DPM particle track"},"content":{"rendered":"

Hello,<\/p>\n

 <\/p>\n

I have been running particle tracking simulatons in both |CFX and Fluent. I am applying almost same conditions for both cases (there are few different settings between two software but I am setting them similarly with workaround methods). However, the particle tracks I get from CFX is always different from Fluent. I want to give example of two basic cases. The first one is a rectangular pipe and simulation details are:<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n

 <\/p>\n<\/td>\n

\n

CFX<\/p>\n<\/td>\n

\n

Fluent<\/p>\n<\/td>\n<\/tr>\n

\n

One-way\/two-way particle coupling?<\/p>\n<\/td>\n

\n

Fully Coupled<\/p>\n<\/td>\n

\n

Fully Coupled<\/p>\n<\/td>\n<\/tr>\n

\n

#of mesh<\/p>\n<\/td>\n

\n

40000<\/p>\n<\/td>\n

\n

40000<\/p>\n<\/td>\n<\/tr>\n

\n

Mesh type<\/p>\n<\/td>\n

\n

CFX<\/p>\n<\/td>\n

\n

Fluent<\/p>\n<\/td>\n<\/tr>\n

\n

Particle shape<\/p>\n<\/td>\n

\n

Spherical<\/p>\n<\/td>\n

\n

Spherical<\/p>\n<\/td>\n<\/tr>\n

\n

Particle material<\/p>\n<\/td>\n

\n

DOS (liquid)<\/p>\n<\/td>\n

\n

DOS (liquid)<\/p>\n<\/td>\n<\/tr>\n

\n

Particle Diameter (Cunningham slip corr:\/ 1)<\/p>\n<\/td>\n

\n

3um<\/p>\n<\/td>\n

\n

3um<\/p>\n<\/td>\n<\/tr>\n

\n

Geometry<\/p>\n<\/td>\n

\n

Same<\/p>\n<\/td>\n

\n

Same<\/p>\n<\/td>\n<\/tr>\n

\n

Boundary Conditions<\/p>\n<\/td>\n

\n

Same<\/p>\n<\/td>\n

\n

Same<\/p>\n<\/td>\n<\/tr>\n

\n

Injection<\/p>\n<\/td>\n

\n

Inlet\/ surface\/ uniform<\/p>\n<\/td>\n

\n

Inlet\/ surface \/uniform<\/p>\n<\/td>\n<\/tr>\n

\n

Flow model<\/p>\n<\/td>\n

\n

Laminar\/no turbulence model added<\/p>\n<\/td>\n

\n

Laminar\/no turbulence model added<\/p>\n<\/td>\n<\/tr>\n

\n

# of particles tracked<\/p>\n<\/td>\n

\n

100<\/p>\n<\/td>\n

\n

100<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

I am using here Cunningham slip correction in ansys and dividing the drag coefficient with slip correction factor in CFX. Actually I used all possible combinations(selecting sphericalin ansys and schiller neuman in cfx… all of them). But Ansys shows no trapped particles while CFX shows trapped ones. (second pic)<\/p>\n

\"\"\"\"<\/span><\/p>\n

To be sure about I applied another basic case elbow. Again here I used the same parameters. You can see the resulting behavior for both fluent and CFX. While ansys resulting no particles are trapped on boundaries, CFX results shows too many particles are trapped. I know the cfx case is correct. The only difference between these two set up is boundary absorption coefficient in CFX. I am assuming all of the particles which touch to the boundary should be absorbed immediately (assigned this value 1). For fluent, I couldnt find how to assign this value. In the boundary conditions in fluent, there is only a selection for reflect,trap and escape. Even though I select trap, I can not have the same result.  I feel somehow I am missing a step. <\/span><\/p>\n

On the other hand, when I increase the particle size in FLuent, I start to see some trapped particles, however in that case I can only see the particles trapped to the corner because of the impaction. I tried to enter a UDF in Ansys which assumes the nodal velocity on the boundary is zero(for the 3um case), this time again I only see the particles trapped because of impaction. <\/span><\/p>\n

If you look at the result pictures carefully and compare them, you will see fluent particle paths are straight while CFX are not. <\/span><\/p>\n

Is there anyone who has an idea what is going on here?<\/span><\/p>\n

 <\/p>\n

\"\"<\/span><\/p>\n

\"\"\"\"<\/span><\/p>\n","protected":false},"template":"","class_list":["post-296720","topic","type-topic","status-closed","hentry","topic-tag-cfx","topic-tag-dispersed-particles","topic-tag-dpm-tracking","topic-tag-DPMUDFparticlestructure-1","topic-tag-fluent","topic-tag-no-slipcondition-1","topic-tag-partcile-tracking","topic-tag-particle-injection-1","topic-tag-particle-trapped"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["11144","852"],"_bbp_author_ip":["23.206.193.150"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1866"],"_edit_lock":["1691056386:205133"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["296720"],"_bbp_forum_id":["27792"],"_bbp_engagement":["852","11144"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["300904"],"_bbp_last_active_id":["300904"],"_bbp_last_active_time":["2023-08-10 15:31:17"]},"test":"egcambustion-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/296720","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/296720\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=296720"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}