/************************************************** ********************* vprofile.c UDF for specifying steady-state velocity profile boundary condition ************************************************** **********************/ #include "udf.h" DEFINE_PROFILE(inlet_x_velocity, thread, position) { real x[ND_ND]; /* this will hold the position vector */ real y, h; face_t f; h = 0.016; /* inlet height in m */ begin_f_loop(f,thread) { F_CENTROID(x, f, thread); y = 2.*(x[1]-0.5*h)/h; /* non-dimensional y coordinate */ F_PROFILE(f, thread, position) = 0.1*(1.0-y*y); } end_f_loop(f, thread) }

Originally Posted by acalado (Post 776195) Check the below https://www.afs.enea.it/project/nept...df/node243.htm

Hello acalado,

I am also working on a Define_Profile velocity, my case is very similar with that problem but I don't get why they define an extra "h" and put that into the definition of "y". Do you know how the code works in that system and do we have to define the position of coordinate vectors like that or is it enough to say y = x [1] and insert that code into inlet boundary condition Does UDF understand where is the [0,0] point of my coordinates? Would be very appreciated if you answer. Thanks.

Best regards,
Bora

Originally Posted by kaboka (Post 781295) Hello acalado, I am also working on a Define_Profile velocity, my case is very similar with that problem but I don't get why they define an extra "h" and put that into the definition of "y". Do you know how the code works in that system and do we have to define the position of coordinate vectors like that or is it enough to say y = x [1] and insert that code into inlet boundary condition Does UDF understand where is the [0,0] point of my coordinates? Would be very appreciated if you answer. Thanks. Best regards, Bora