Flow structure formed due to interaction of a supersonic jet with a porous obstacle
Results of studying impingement of a supersonic underexpanded air jet onto a finite-thickness porous metal obstacle whose frontal plane is normal to the jet axis and whose side surface is impermeable for the gas flow are reported. The case of a non-porous obstacle of the same diameter is considered for determining the effect of porosity on gas-dynamic characteristics of jet–obstacle interaction.
A finite 3D element model coupled with a 2D finite volume one has been developed obatained in order to study the miscrostruture evolution during the desification of a green compact obtained by powder metturgy [1]. The simulation of the process was performed on to grains considering surface diffusion of the grains, grain boundary diffusion and volume diffusion in the grains, with as source terms the radii of curvature. The stress gradients are the driving forces of sintering. The mechanical behaviour of the grains is considered as elastic in the whole temperature range of the sintering cycle.