{"id":218627,"date":"2022-07-15T17:06:19","date_gmt":"2022-07-15T17:06:19","guid":{"rendered":"\/forum\/forums\/topic\/marangoni-shear-stress\/"},"modified":"2022-07-15T17:06:19","modified_gmt":"2022-07-15T17:06:19","slug":"marangoni-shear-stress","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/marangoni-shear-stress\/","title":{"rendered":"Marangoni Shear Stress"},"content":{"rendered":"
DEAR all<\/div>\n
I want to simulate the laser welding with the FLUENT. I just activate the solidification and melting (without VOF). I face a problem to import the Marangoni effect into my simulation. In the BOUNDARY CONDITION (MARANGONI STRESS), I found the formula for surface tension gradient variation base on the temperature. Since I could not import the surface tension gradient by UDF in the MARANGONI STRESS, I try to import this effect by UDF in the SPECIFIED SHEAR. I attach the formula for this part and shot screen of specified stress.<\/div>\n
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To be honest, I do not know which Macro I should use to write this formula. I try DEFINE_PROPERTY and DEFINE_PROFILE. In my UDF, I consider the surface tension graidient as a constant. Everytime I run this code, Fluent would close. It is very painful. Please help me to find the error of this UDF.<\/strong><\/div>\n
Here you can find the UDF that I wrote for this part.<\/div>\n
DEFINE_PROFILE(marangonix, t, i)<\/div>\n
{<\/div>\n
face_t f;<\/div>\n
cell_t c;<\/div>\n
Thread *tc;<\/div>\n
real grad_temp, gama_temp;<\/div>\n
begin_f_loop(f,t)<\/div>\n
{<\/div>\n
c=F_C0(f,t);<\/div>\n
tc = THREAD_T0(t);<\/div>\n
\/\/tc=F_C0_THREAD(f,t);<\/div>\n
grad_temp= C_T_G(c,tc)[0];<\/div>\n
gama_temp=-0.00043;<\/div>\n
F_PROFILE(f,t,i)=gama_temp*grad_temp;<\/div>\n
}<\/div>\n
end_f_loop(f,t)<\/div>\n
}<\/div>\n
 <\/div>\n
DEFINE_PROFILE(marangoniy, t, i)<\/div>\n
{<\/div>\n
face_t f;<\/div>\n
cell_t c;<\/div>\n
Thread *tc;<\/div>\n
real grad_temp, gama_temp;<\/div>\n
begin_f_loop(f,t)<\/div>\n
{<\/div>\n
c=F_C0(f,t);<\/div>\n
tc = THREAD_T0(t);<\/div>\n
\/\/tc=F_C0_THREAD(f,t);<\/div>\n
grad_temp= C_T_G(c,tc)[1];<\/div>\n
gama_temp=-0.00043;<\/div>\n
F_PROFILE(f,t,i)=gama_temp*grad_temp;<\/div>\n
}<\/div>\n
end_f_loop(f,t)<\/div>\n
}<\/div>\n
 <\/div>\n
DEFINE_PROFILE(marangoniz, t, i)<\/div>\n
{<\/div>\n
face_t f;<\/div>\n
cell_t c;<\/div>\n
Thread *tc;<\/div>\n
real grad_temp, gama_temp;<\/div>\n
begin_f_loop(f,t)<\/div>\n
{<\/div>\n
c=F_C0(f,t);<\/div>\n
tc = THREAD_T0(t);<\/div>\n
\/\/tc=F_C0_THREAD(f,t);<\/div>\n
grad_temp= C_T_G(c,tc)[2];<\/div>\n
gama_temp=-0.00043;<\/div>\n
F_PROFILE(f,t,i)=gama_temp*grad_temp;<\/div>\n
}<\/div>\n
end_f_loop(f,t)<\/div>\n
}<\/div>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-218627","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["252317","118","22555"],"_bbp_author_ip":["66.198.8.115"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["716"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["218627"],"_bbp_forum_id":["27792"],"_bbp_engagement":["118","22555","252317"],"_bbp_voice_count":["3"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["218706"],"_bbp_last_active_id":["218706"],"_bbp_last_active_time":["2022-07-18 08:49:45"]},"test":"pourya-heidarimail-polimi-it"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/218627","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\/218627\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=218627"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}