Figures 5 and 6 show the volume fra

Figures 5 and 6 show the volume fractions of both
metal and air during the simulation process. With these
pictures, it is easier to estimate air entrapment. It can be
seen that when the two waves collide there is a large air
entrapment which will enter into to cavity with the metal.
(Colour scale: White is 100% metal and blue is 100% air)
Fig.5 and 6. . Volume fraction picture illustrates air
entrapment and how the air mixes with the metal. In these
pictures, it can be seen how the two waves form an air
bubble inside the sleeve. (Colour scale - volume fraction:
White is 100% metal and blue is 100% air)
The second simulation was done using two constant
plunger accelerations. The wave fronts which form stay
together and hit the cylinder head at the same speed.
There is minimal air entrapment. The plunger movement
and the wave formation are shown in figures 7 and 8.
Unlike modelling the flow of sand casting and
injection moulding, for fluid flow model in die casting, the
solution of the complete Navier Stokes equations
including the convection terms to calculate transient
velocity and pressure changes is essential requirement.
The other requirement is free surface modelling of the
fluid flow, which is capable of tracking complicated flow
fronts as well as the formation of jets and flow separation
caused by high velocities