Numerical Simulation of Shock Wave Interaction with a Slab of Compressible Foam Attached to a Solid Wall

Numerical simulation of normal shock wave interaction with a slab of
compressible foam attached to a solid wall is the scope of the present work.
The foam is modeled as solid particles suspended in air. Therefore, the fo& is
treated as two-phase medium of solid particles and air. The drag force and heat
transfer between particles and air are taken into consideration. The influerice of
foam density, incident shock Mach number and foam slab length on the
reflected and transmitted waves strength, on the flow field inside and outside
the foam and also on the pressure at solid wall behind the foam are studied.
The numerical results reflect all the salient features of the interaction process
and its conseauences. The results of the present numerical simulation are
compared wi& experimental results of ~kews[1991] and showed a satisfactory
agreement. It is shown that the effect of increasing foam length is to delay the
arrival of the transmitted wave to the solid wall and the rna~mum pressure at
wall increases slightly. In addition, the rate of wall pressure increase is greater
for smaller foam length. The increase in incident shock Mach number increases
the wall pressure and the rate of increase is greater for greater incident Mach
number. The pressure at the wall decreases after reflection to almost constant
value in the used tune span. This constant value increases with the increase in
incident Mach number. The numerical results showed also that the delay in the
arrival of transmitted wave to the solid wall is greater for greater foam density.
The maximum pressure at the solid wall decreases with the increase of foam
density, but it decays to almost constant value regardless of the foal density.
The maximum pressure at wall with foam attached to it considerably exceeds