Dear All How apply the fuction for velocity profile in nodes not face_t or centroed for face. I need aply this fuction at nodes. can any one to help me many thanks emad

Hello Emad

As I guess this profile is on a plane you want to change the nodal values of certain faces. There is an example of Looping over Nodes of a Face (f_node_loop) (also Cell separately) in the UDF Manual:

face_t f; Thread *t; int n; Node *node; f_node_loop(f,t,n) { . . . node = F_NODE(f,t,n); . . . }

Also NODE_X(node) returns the x co-ordinate of the node pointed to by *node. (similar macros for y and z) so the position can be found.

Afraid I can't see how to change any of the node values let alone the 'i'th property.

Hope this was some help. Kris

Dear Mr. Kris Many thanks for reply. but if appled your advice for velocity profile in inlet 2d duct (1 * 10)m. if plot velocity at inlet duct and taking node values under options for xy plot for fluent the data appear as

vel y-coor ---- ------ 0.108 1 0.192 0.9 0.252 0.8 0.288 0.7 0.3 0.6 0.288 0.5 0.252 0.4 0.192 0.3 0.108 0.2 0 0.1 0 0

at y=1 should be velocity aqual to zero. My UDF for velocity profile as:- //--------------------------------------------------------------------------- #include "udf.h"

//u=Uave*(3/2)*(1-(y-h/2)/h/2)**2) //taking h=1 and Uave=0.2 m/s DEFINE_PROFILE(vel2d_inlet_velocity,t,i)

{

real x[ND_ND]; real rady; real py; //real z,y; face_t f; Node *v; int n; begin_f_loop(f,t) { f_node_loop(f,t,n)

{

v = F_NODE(f,t,n);

py=(NODE_Y(v)-0.5)/0.5; rady = (1.0-pow(py,2));

F_PROFILE(f,t,i) = 0.2*(3.0/2.0)*rady; } } end_f_loop(f,t) }

Many thanks agains for help me emad