{"id":343489,"date":"2024-01-06T08:53:16","date_gmt":"2024-01-06T08:53:16","guid":{"rendered":"\/forum\/forums\/topic\/udf-for-pistion-motion-in-layering-technique\/"},"modified":"2024-01-06T08:53:16","modified_gmt":"2024-01-06T08:53:16","slug":"udf-for-pistion-motion-in-layering-technique","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/udf-for-pistion-motion-in-layering-technique\/","title":{"rendered":"UDF for Pistion Motion in Layering technique"},"content":{"rendered":"

I am writing the UDF of Pistion motion In Layering technique as the profile is not working. <\/p>\n

This is a 3D problem.<\/p>\n

The compiled UDF is given as below:<\/p>\n

include “udf.h”
#include “dynamesh_tools.h”
DEFINE_CG_MOTION(piston,dt,vel,omega,time,dtime)
{
NV_S(vel, =, 0.0);
NV_S(omega, =, 0.0);
vel[0]=1;<\/h1>\n

time = 1;<\/h1>\n

dtime = 0.001;
printf(“\\n”);
printf(“\\n x_velocity = %g \\n”, vel[0]);
}<\/h1>\n

as above the piston moving at 1000mm\/sec speed. To lower the computational time i am moving at this only with stroke length of 260mm. But while changing the number of time step to 280 with time step size 0.001. The fluent getting crashed. <\/p>\n

i am not sure what causing the problem in the solution, is it UDF or simulation setup.<\/p>\n","protected":false},"template":"","class_list":["post-343489","topic","type-topic","status-closed","hentry","topic-tag-ansys-cfd-1","topic-tag-cfd-icfluent","topic-tag-cfd-udf-fleunt","topic-tag-fluent","topic-tag-udf"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["4770","15180"],"_bbp_author_ip":["96.7.218.215"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["429"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["343489"],"_bbp_forum_id":["27792"],"_bbp_engagement":["4770","15180"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["343635"],"_bbp_last_active_id":["343635"],"_bbp_last_active_time":["2024-01-08 13:29:31"]},"test":"shubcgodrej-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/343489","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\/343489\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=343489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}