Hi my friend, please help me for create solid viscosity UDF in fluidized bed simulation. I creat below experssion in C++ as example, but i don't know that this experssion is correct or not, please guide me. thanks for your attention.

My UDF is: #include "udf.h" #define pi 4.*atan(1.) #define maxvoid 0.63 #define es 0.9 #define diam2 2.75e-4

DEFINE_PROPERTY(cell_solid_viscosity, cell, thread) { real rho_s,void_s,grant,rdf,vdrs,ali,ziri,miuscv,miuskv ,mius;

/* find phase velocities and properties*/

rho_s = C_R(cell, thread);

void_s = C_VOF(cell, thread);/* solid vol frac*/

/* find solid phase properties*/

rho_s = C_R(cell, thread); grant=C_GT(cell,thread);

/* find below value */ vdrs = void_s*diam2*rho_s*sqrt(grant*pi); ali = 1+(1+es)*(1.2*es-0.4)*(void_s*rdf); ziri = 6*(3-es); /* compute radial distribution function */ rdf = (3/5)*pow((1-pow((void_s/maxvoid), 0.33333)),-1); /* compute solid collition viscosity */ miuscv = 0.8*void_s*rho_s*diam2*rdf*(1+es)*pow((grant/pi),0.5); /* compute solid kinetics viscosity */ miuskv = vdrs*ali/ziri; /* compute solid shear viscosity */ mius = miuscv + miuskv; return mius; } thanks.