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-   -   UDF paraboloid velocity inlet (https://www.cfd-online.com/Forums/fluent/31593-udf-paraboloid-velocity-inlet.html)

 Ronak Shah June 4, 2003 09:44

UDF paraboloid velocity inlet

Hi, I am new student working on the UDF paraboloid velocity inlet problem. I read the information posted by rosco <rosco1998@hotmail.com>Date: Sun, 18 May 2003, 11:37 a.m. subject: UDF paraboloid velocity inlet and the responses he received regarding his problem. I have a similar problem but the case here is the inlet is in the xy plane. or in other words the the origin of the reference system is not in the center of the inlet pipeinlet pipe, it is about 30 degrees from the x-axis. I am looking for modifications I would need in this code to have it work... Here's the code. Remember it requires you have the origin of your reference system in the center of the inlet pipe.

If you need to change diameter and average velocity, change their values in the corresponding #define.

#include "udf.h"

#define PIPE_DIAMETER 10.e-3 // Set here the diameter of your pipe in meters

#define AVG_Z_VELOCITY 1. // Set here the average z velocity at inlet in m/s

DEFINE_PROFILE(paraboloid_velocity, thread, position) { real x[ND_ND];

real coeff,r,v_max;

face_t f;

v_max = 2.*AVG_Z_VELOCITY; //Calculating paraboloid vertex z (max velocity)

coeff = -v_max/pow(r,2.);

{

F_PROFILE(f, thread, position) = coeff*(pow(x,2.) + pow(x,2)) + v_max;