[amilachandra]

A. Haider, O. Levenspiel, Drag coefficient and terminal velocity of spherical and nonspherical.
particles, Powder Technol. 58 (1989)
I have modified nonspherical drag law by adding drag multiplier as coded following UDF. UDF is working without issue. But I want to know any reference test case which is dilute phase and nonspherical particle involve validating the UDF.
If someone know simple test case with experimental data, please comment the research article.


/************************************************** *********************
A. Haider, O. Levenspiel, Drag coefficient and terminal velocity of spherical and nonspherical
particles, Powder Technol. 58 (1989)
************************************************** **********************/
#include "udf.h"
#define shf 1 /*Particle shape factor*/
#define dcm 1 /*Drag coefficient multiplyer*/


#define RGASU UNIVERSAL_GAS_CONSTANT /*Universal gas conatanat (J/(kmolK))*/
DEFINE_DPM_DRAG(particle_drag_force,Re,tp)
{

real b1, b2, b3, b4,Cd1, drag_force;
b1=exp(2.3288-6.4581*shf+2.4456*pow(shf,2));
b2=0.0964+0.5565*shf;
b3=exp(4.905-13.8944*shf+18.4222*pow(shf,2)-10.2599*pow(shf,3));
b4=exp(1.4681+12.2584*shf-20.7322*pow(shf,2)+15.8855*pow(shf,3));
Cd1=(24*(1+b1*pow(Re,b2))/Re)+(b3*Re/(b4+Re));
drag_force=dcm*18*Cd1*Re/24;

return (drag_force);
}