[Prikane]

Dear colleagues,

I am using UDF for dynamic mesh which is hooked with half cylinder boundary. In my UDF (which I found online in one PhD thesis), there is one formula which calculates elastic deformation of cylindrical boundary.

FORMULA FOR ELASTIC DEFORMATION:
sump=sump+(p_array[j]/Er)*(4*cj*log(2*by)+(aa-cj)*log((aa-cj)*(aa-cj))-(aa+cj)*log((aa+cj)*(aa+cj))) ;

PARAMETERS:
aa=X[i]-X[j] ;
cj=(X[j]-X[j-1])/2 ;

I have a problem with understanding what these 'aa' and 'cj' parameters mean? It seems like they are some geometrical relations between boundary nodes, but since I started using Fluent recently, I can not understand their role in formula for elastic deformation.

If someone can help me to understand these parameters I would be very grateful.

Thanks in advance,

Prikane