{"id":51907,"date":"2021-02-04T09:53:45","date_gmt":"2021-02-04T09:53:45","guid":{"rendered":"\/forum\/forums\/topic\/long-iteration-time-in-fluent-2\/"},"modified":"2021-02-04T09:53:45","modified_gmt":"2021-02-04T09:53:45","slug":"long-iteration-time-in-fluent-2","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/long-iteration-time-in-fluent-2\/","title":{"rendered":"Long iteration time in Fluent"},"content":{"rendered":"<p>I am using DEM collision model where I predefined few particles with density of 2650 Kg\/m^3 inside the pipe, The pipe diameter = 0.0042m, length L= 1m. nParticle initial conditions can be read from an external file. at time = 0, (334) particles are placed at random position within the pipe. The velocity of the particles in radial direction is chosen randomly from -v to v= 0.01, while the particle velocity in axial direction is set to zero. nThe collision parameters for the collision pairs was Herzian_dashpot for normal contact force and friction_dshf_rolling for tangential force. nPeriodic boundary condition is applied in the axial direction with specified air mass flow in same direction of zero Kg\/s.nTransient model, with unsteady particle tracking, and the gravity was activated, so the particles are falling in the axial direction.nI have run 334 particles for 10000-time steps, with 0.0001s time step size. The solution was successfully converged, but the calculation time took extremely long time (more than 24 hrs. for 40% Iteration).nAccording to the calculation of collision time and martial properties mentioned above, I should use time step size about 10^-5, with 100000-time steps, which supposed to have longer iteration time.I appreciate any advice on setup and\/ or parameter that can help in reducing the iteration time. Thanks in advance.nnAbinn<\/p>\n","protected":false},"template":"","class_list":["post-51907","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["24185"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":["??\u0006\f"],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0"],"_btv_view_count":["1046"],"_bbp_subscription":["231942"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["51907"],"_bbp_forum_id":["27792"],"_bbp_engagement":["62","199","22555","184899"],"_bbp_voice_count":["4"],"_bbp_reply_count":["19"],"_bbp_last_reply_id":["141715"],"_bbp_last_active_id":["141715"],"_bbp_last_active_time":["2021-02-09 13:24:47"]},"test":"za36kuzo"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/51907","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\/51907\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=51907"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}