A new mass-weighted(MAW)upwind interpolation scheme
the control-volume finite-element method
is adopted for three dimensional convection term based on tetrahedral element
and its subcontrol volumes and surfaces on each element are symmetrical.This feature not only guarantees the positive coefficients in the discretization equation
but also is easy to be fulfilled in the computer program.The scheme has been applied successfully to some three dimensional convection-diffusion problems and some three dimensional viscous