Learning Forum

[Danmei]

Hi all,nI'm running a simple multiphase simulation of a tank. I use mixture model and standard k-e. nothing else. In the model, I need to take the second phase out if it hit the bottom floor with a certain velocity, similar to degassing boundary condition, by using udf. I used DEFINE_ADJUST to calculate the mass source and used DEFINE_SOURCE to add the source term. nI am receiving this error message everytime I hit the calculation button: Node 0: Process 25932: Received signal SIGSEGVnI have several check points here:nThe udf compiled and loaded properly nI set the UDM location to 1 before I build and load the udfnI also tried initializing the system by calculating it without udf first, as suggested on the forum, it didn't helpnThe model runs well without udfnI tried to hook up the my_adjust only, it gave me the same error, it seems like it has something to do with the DEFINE_ADJUST part onlynI tried both steady-state and transient, the results are the samenI also tried to interpret the udf instead of compiling, it didn't helpnI made sure that the zone ID are correctnCan someone please help me?n#include udf.hnnDEFINE_ADJUST(my_adjust1, d)n{ntThread *t, **pt;ntface_t f;ntcell_t c;nntt = Lookup_Thread(d, 9);nttbegin_c_loop(c, t)nt{nttC_UDMI(c,t,0)=0.0;nttpt=THREAD_SUB_THREADS(t);nttif (C_V(c, pt[1]) < 0.0)ntttC_UDMI(c,t,0) = -1.368*C_R(c, pt[1])*C_VOF(c, pt[1])*C_V(c, pt[1]);nt}ntend_c_loop(c, t)nn}nnDEFINE_SOURCE(bot_source1, c, t, dS, eqn)n{ntThread *super_t = THREAD_SUPER_THREAD(t);ntreturn (-1.0*C_UDMI(c,super_t,0));n}n

[Karthik Remella]

Hi,nPlease try and remove the Define_Source part of the code from the UDF and see if you resolve this issue. nHere is a link from the Fluent Customization manual on how DEFINE_SOURCE should be used. nhttps://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v202/en/flu_udf/flu_udf_sec_define_source.htmlnThanks.nKarthik n

[Danmei]

Hi,nSorry for the late reply. The email somehow went to my junk mailbox.nI deleted the source part, it still gives me the same error when I tried to run.nI also tried setting the C_UDMI as a constant. It didn't report error. I assume it has something to do with Fluent cannot retrieve the some values of pt[1]. But I do need to read a the value of the specific phase in mixture that's why I used pt[1].nAny idea?.And thank you for your help!n

[Karthik Remella]

Please check out the following UDF example and see if you can tailor your UDF similar to this. 2.4.3.4. Example 2 - Custom Lift LawnI hope this helps.nThanks,nKarthikn