# USING IF statement in a UDF for defining Velocity profile at Inlet

 Register Blogs Members List Search Today's Posts Mark Forums Read

 July 19, 2012, 16:35 USING IF statement in a UDF for defining Velocity profile at Inlet #1 Member   Join Date: May 2009 Posts: 58 Rep Power: 8 Hi, I want to define a velocity profile at my inlet boundary condition. This is my UDF which is working for parabolic velocity, but I want to add a function for y<0.003 and another one for y>0.004, so I need to define and if statement. but UDF does not underestand y in the line (If y<0.003). How could I define y in my IF statement? Thanks. #include "udf.h" DEFINE_PROFILE(inlet_x_velocity, thread, position) { real x[ND_ND]; real y, v; face_t f; begin_f_loop(f,thread) { F_CENTROID(x, f, thread); y = x[1]; If (y<0.003) v= -228.*y+11.6; else v=-10200.*y+41.52 F_PROFILE(f, thread, position)=v; } end_f_loop(f, thread) }

 July 19, 2012, 17:04 #2 Senior Member     Alex Join Date: Jun 2012 Location: Germany Posts: 1,098 Rep Power: 19 Very strange. I can't see any error. But instead of assigning the value of x[1] to the variable y, you could try using x[1] directly in the if-statement and the equation.

July 19, 2012, 17:09
#3
Member

Join Date: May 2009
Posts: 58
Rep Power: 8
Quote:
 Originally Posted by flotus1 Very strange. I can't see any error. But instead of assigning the value of x[1] to the variable y, you could try using x[1] directly in the if-statement and the equation.

I tried that before, did not work.

It gave me an error indicating that the undeclared variable in IF statement.
Does it underestand the y variable in If statement?

 May 23, 2013, 23:46 #4 Member   Anonymous Join Date: Apr 2013 Posts: 34 Rep Power: 4 Hey Amir, I am facing the same problem. My UDF doesn't understand the if statement. How did you fix your problem?

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post jill FLUENT 8 February 10, 2015 07:04 egge24 Fluent UDF and Scheme Programming 0 April 4, 2012 19:57 Janshi STAR-CCM+ 4 March 14, 2012 11:21 rosco FLUENT 5 September 1, 2011 02:29 Armengol FLUENT 3 September 30, 2009 15:08

All times are GMT -4. The time now is 18:55.