[teojb]

Hi, I am trying to create an erosion model based on DNV standards. I managed to interpret the UDF and run the calculation but the erosion rate remains at 0 everywhere when I plot the contour. Are the lines for the thread and cell necessary?



#include "udf.h"

DEFINE_DPM_EROSION(DNV, p, t, f, normal, alpha, Vmag, mdot)

{

real A[ND_ND];

Thread *t0;

cell_t c0;

/*t0 = THREAD_T0(t);*/ /*error interpreting these two lines*/

/*c0 = F_C0(f,t);*/

real erosion, F_alpha; F_alpha = 0.6*(pow(((sin(alpha))+7.2*((sin(alpha))-(pow((sin(alpha)),2.0)))),0.6))*(1-exp((-20)*alpha));

erosion = (3.67e-4)*F_alpha*(pow(Vmag,2.6))*mdot; /*mm per year*/ F_STORAGE_R(f,t,SV_DPMS_EROSION) =erosion;

}

[AlexanderZ]

#include "udf.h" 
#include "math.h" 

DEFINE_DPM_EROSION(DNV, p, t, f, normal, alpha, Vmag, mdot) 
{ 
real erosion, F_alpha;
F_alpha = 0.6*(pow(((sin(alpha))+7.2*((sin(alpha))-(pow((sin(alpha)),2.0)))),0.6))*(1-exp((-20)*alpha)); 
erosion = (3.67e-4)*F_alpha*(pow(Vmag,2.6))*mdot; /*mm per year*/ 
F_STORAGE_R(f,t,SV_DPMS_EROSION) =erosion; 
}

best regards

[teojb]

Originally Posted by AlexanderZ

#include "udf.h" 
#include "math.h" 

DEFINE_DPM_EROSION(DNV, p, t, f, normal, alpha, Vmag, mdot) 
{ 
real erosion, F_alpha;
F_alpha = 0.6*(pow(((sin(alpha))+7.2*((sin(alpha))-(pow((sin(alpha)),2.0)))),0.6))*(1-exp((-20)*alpha)); 
erosion = (3.67e-4)*F_alpha*(pow(Vmag,2.6))*mdot; /*mm per year*/ 
F_STORAGE_R(f,t,SV_DPMS_EROSION) =erosion; 
}

best regards

Thanks AlexanderZ. I compiled the above code but it is still showing zero erosion rate. I can see the erosion rate if I change to the default erosion models.

[AlexanderZ]

check your equations

best regards

[teojb]

Turns out that there were some changes in the define_dpm_erosion macro in Fluent 2019 R1/Ansys 19.3. Leaving the code below for reference.

#include "udf.h" 
#include "math.h" 

DEFINE_DPM_EROSION(DNV, tp, t, f, normal, alpha, Vmag, mdot)
{ 
real erosion, F_alpha;
F_alpha = 0.6*(pow(((sin(alpha))+7.2*((sin(alpha))-(pow((sin(alpha)),2.0)))),0.6))*(1-exp((-20)*alpha)); 
erosion = (3.67e-4)*F_alpha*(pow(Vmag,2.6))*mdot; /*mm per year*/ 
F_STORAGE_R_XV(f, t, SV_DPMS_EROSION, EROSION_UDF)=erosion;}

[blacksmith]

Originally Posted by teojb

Turns out that there were some changes in the define_dpm_erosion macro in Fluent 2019 R1/Ansys 19.3. Leaving the code below for reference.

#include "udf.h" 
#include "math.h" 

DEFINE_DPM_EROSION(DNV, tp, t, f, normal, alpha, Vmag, mdot)
{ 
real erosion, F_alpha;
F_alpha = 0.6*(pow(((sin(alpha))+7.2*((sin(alpha))-(pow((sin(alpha)),2.0)))),0.6))*(1-exp((-20)*alpha)); 
erosion = (3.67e-4)*F_alpha*(pow(Vmag,2.6))*mdot; /*mm per year*/ 
F_STORAGE_R_XV(f, t, SV_DPMS_EROSION, EROSION_UDF)=erosion;}

Thank you teojb,

your reference code helps me to solve my problem.

Regards,
Xiao