A general guideline of model meshing is to always
mesh the more critical domains (i.e. high velocity, high
pressure or pressure drop flow fields) in advance of the less
critical ones. For TBIM, the more critical domains include the
regions around the openings of throttle valve and the injector
(Fig. 2). The fineness of grid applied increases with the
criticalness of a domain. After TBIM was appropriately
meshed, the boundary conditions of TBIM were identified for
the air inlet, fuel outlet, mixture outlet and the symmetry plane
(Fig. 2). Boundary conditions of ‘pressure inlet’ and ‘mass flow
inlet’ were selected for the air inlet and fuel outlet, whereas the
mixture outlet and the symmetry plane were given the boundary
condition of ‘wall’. These choices of boundary condition were
depending on the available data and also the data required from
the simulation.