CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

udf inlet velocity is not set correctly, why ?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 17, 2008, 08:33
Default udf inlet velocity is not set correctly, why ?
  #1
GaoGe
Guest
 
Posts: n/a
Hi,

While i show the inlet velocity in plot window,the figure is strange, in the zone that z<-10, the velocity is not 10,it shows 2,why?

Thanks a lot in advance.

best regards, Bob De Clercq

/************************************************** ****************/ /* velo.c*/ /*UDF for grads wind profile boundary condition Park10Unm_windvelo*/ /************************************************** ****************/ #include "udf.h"

#define Um 10 #define Zm 10 #define Z0 0.025 #define H 5 #define B 0.0706 #define K 0.4 #define Zo2 0.3 #define one 1

DEFINE_PROFILE(Park10Um_windvelo, t, i) { real x[ND_ND], ux , ux2, z ,media ; /* */ real absz ; cell_t c ; ux = K*Um /(log(Zm/Z0)); ux2 =ux/(pow((Z0/Zo2),B)); begin_c_loop(c, t) {

C_CENTROID(x,c,t);

z = x[2];

absz=z+15;

if (absz <= H )

C_PROFILE(c,t,i) =Um;

else

media =(absz-H+Zo2/K)/Zo2;

C_PROFILE(c,t,i) =(one/K)*ux2*log (media); } end_c_loop(f,c) }

this

  Reply With Quote

Reply

Thread Tools
Display Modes

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Steady pipe flow mean velocity higher than inlet velocity anita OpenFOAM Running, Solving & CFD 7 September 25, 2012 05:35
velocity inlet vs pressure inlet cheong FLUENT 6 April 9, 2011 03:07
velocity profile as an velocity inlet condition KEES Main CFD Forum 0 April 15, 2008 11:26
tangential velocity on a velocity inlet in 2D bretti FLUENT 0 July 3, 2007 08:42
reversed flow at velocity inlet / mass flow inlet ib FLUENT 1 March 26, 2007 13:11


All times are GMT -4. The time now is 17:48.