[leewenlong]

PBM!!!! I want to write an UDF for electric coalescence kernel function. The equations
and UDF code are as follow. But someting is wrong with the code. Please help me to correct them.
Thank you for your attention.
DEFINE_PB_COALESCENCE_RATE(aggregation_kernel, c, t, d_1, t_2, d_2)
{
real f_1, f_2, lamuta, alpha, miu_ratio = miu_1/miu_2, agg;/*miu_1 and 2 are viscosity for two phases.*/

if (d_1>d_2)
lamuta = d_2/d_1, alpha = d_1;
else
lamuta = d_1/d_2, alpha = d_2;

f_1 = 2250*(miu_ratio+1)*pow(alpha,2)*(1-pow(lamuta,2))/(0.151263*miu_ratio+0.100842);
f_2 = 2.8*3*(1-lamuta)*pow(UM4,2)/(2*9.8*lamuta*114.8*alpha);
zhang_agg = 0.785*pow(d_1+d_2,2)*f_1*0.45*pow(f_2,0.55);
return agg;
}

[leewenlong]

PLEASE not consider the case in absence of electric field. And the paper is attached. http://dx.doi.org/10.1016/j.jtice.2015.06.028

[AlexanderZ]

what is wrong?

best regards

[leewenlong]

I do not know where and why was wrong with it. the code can run in fluent. but the results are incorrect. thank you for your reply!

[AlexanderZ]

take a look into your code

if (d_1>d_2)
lamuta = d_2/d_1, alpha = d_1;
else
lamuta = d_1/d_2, alpha = d_2;

from my point of view should be:

if (d_1>d_2)
{lamuta = d_2/d_1; alpha = d_1;}
else
{lamuta = d_1/d_2; alpha = d_2;}

may be this will help. You should compile this code.

best regards