Numerical Simulation of Shock Wave Interaction with a Slab of Compressible Foam Attached to a Solid Wall
ERJ. Engineering Research Journal
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,
... ed 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  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 r n a~m u m 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 f o a l density. The maximum pressure at wall with foam attached to it considerably exceeds Manuscript received fromDr. Ahmed A.