求质量流量的两种方法，求解答

aleisia

1.
begin_f_loop(f,t)
if PRINCIPAL_FACE_P(f,t) /* tests if the face is the principle face FOR COMPILED UDFs ONLY */
{
NV_D(flux, =, F_U(f,t), F_V(f,t), F_W(f,t)); /* defining flux in terms of velocity field */
NV_S(flux, *=, F_R(f,t)); /* multiplying density to get flux vector */
F_AREA(A,f,t); /* face normal vector returned from F_AREA */
massflowrate += F_YI(f,t,i)*NV_DOT(flux,A); /* dot product of the inlet surface flux and area vector, multiplied by the mass fraction of species i */
}
end_f_loop(f,t)

2.
if PRINCIPAL_FACE_P(f,t) /* tests if the face is the principle face FOR COMPILED UDFs ONLY */
{
massflowrate += F_YI(f,t,i)*F_FLUX(f,t)*F_AREA(A,f,t); /* dot product of the inlet surface flux and area vector, multiplied by the mass fraction of species i */
}

不知道我的理解对不对，上面两个方法里的 begin_f_loop 和 end_f_loop, right到底需要不需要呢？
F_FLUX(f,t)和F_AREA(A,f,t)是矢量，要用NV_DOT的方式来求点积，再和F_YI（f,t,i）相乘，如何？可是这个F_YI(f,t,i)却是一个数组啊，不是一个单独的具体的数...
难道NV_DOT(flux,A)也是一个数组？

谢谢