UDF for a 2d vaned diffuser inflow velocity
 

hi guys..am new to cfd-online...
myself shiva...doing Mtech project in vaned diffuser analysis in fluent...i need a UDF for vaned diffusser....it is in polar co-ordinates.
x component velocity is 329.39*cos(tan^-1(y/x)-71.56)
y component velocity is 329.39*sin(tan^-1(y/x)-71.56)
can u guide me to create a UDF please
theta (y/x) is changing with respect to center of the inner circle
can i import a two UDF for a velocity...plz guide me guys...Attachment 25107

please help me guys.....urgent....!!!..plzzz
my mail id = contactshiva@ymail.com

i created a UDF for my problem but my contour is not matching...is this udf correct or not..please help me out...!!!

#include "udf.h"
DEFINE_PROFILE(inlet_x_velocity, thread, position)
{
real x[ND_ND];
real xcord;
real ycord;
face_t f;
begin_f_loop(f, thread)
{
F_CENTROID(x,f,thread);
xcord=x[0];
ycord=x[1];
F_PROFILE(f, thread, position) =(375.510*cos(atan(ycord/xcord)-71.56));
F_PROFILE(f, thread, position) =(375.510*cos(atan(ycord/xcord)-71.56));
}
end_f_loop(f, thread)
}

am using density based solver..inviscid flow....please guys am waiting for ur reply