hi, everyone, I work with the cavitation model in Fluent (diphasique model, mixture), I like modifier the turbulent viscosity by UDF. I compile the UDF in FLUENT with no problem, but when I start calculating, FLUENT gives me this: Error: FLUENT received fatal signal (ACCESS_VIOLATION) 1. Note exact events leading to error. 2. Save case/data under new name. 3. Exit program and restart to continue. 4. Report error to your distributor. Error Object: () Here is my little UDF: #include "udf.h" DEFINE_TURBULENT_VISCOSITY(mu_t_ke, c ,t) { real mu_t; real rho = C_R(c,t); real k = C_K(c,t); real d = C_D(c,t); real cmu = M_keCmu; real vof = C_VOF(c,t); mu_t = vof*1000*cmu*k*k/d; return mu_t; } I thing that the problem is the vof , what can I do? Thank you very much

Hi; I think that your problem follows from the use of C_VOF(c,t) macro. What version of FLUENT do you use? I could not use this macro with 6.0 version successfuly, but I can with 6.1 or 6.2 version. For more informations, look at FLUENT6.1 or 6.2 UDF manual. There is a UDF describing mass transfer through boiling. Do you want to model cloud cavitation? A turbulent model modification proposed by reboud et. al. exists that utilizes each phase density instead of volume fraction. I have applied this modification with success. Best regards,

ROOZBEH

Hi, Yes, I want to model cloud cavitation with the modification proposed by reboud et. al. But I use the last version of Fluent (6.2.16) and the problem continue. What can I do?