File: /nfs/home/0/users/jenkins/mfix.git/model/GhdTheory/chi_ij_GHD.f

1           subroutine chi_ij_GHD(s,i,j,sigmai,phi,ni,chi_ij)
2           Implicit NONE
3     
4           integer s
5           double precision pi
6           parameter (pi=3.14159265458979323846d0)
7     
8           integer i,j
9           double precision sigmai(s)
10           double precision phi
11           double precision ni(s)
12     
13           integer kk
14           double precision beta
15           double precision phi_g
16           double precision sigma_ij
17           double precision group1
18           double precision chi_ij
19     
20           beta = 0.d0
21           do kk=1,s
22              beta = beta + pi/6.d0*ni(kk)*sigmai(kk)**2
23           enddo
24           phi_g = 1d0-phi
25           sigma_ij = 0.5d0*(sigmai(i)+sigmai(j))
26           group1 = (sigmai(i)*sigmai(j))/sigma_ij
27     
28           chi_ij = 1.d0/phi_g + 1.5d0*beta/phi_g**2*group1 &
29                    + 0.5d0*beta**2/phi_g**3*group1**2
30     
31           return
32           end subroutine chi_ij_GHD
33