“…The following assumptions are used to describe the motion of this system: the particles of the powdered medium are incompressible singlefraction spherical solid inclusions; the particle sizes in the mixture are much greater than the molecularkinetic scales and much smaller than distances that reveal noticeable changes in macroscopic parameters of the phases (outside the shock waves); viscous and heatconduction effects are significant only in interphase interaction processes; processes of interphase mass transfer, fragmentation, and sintering of particles are ignored; effects of fluctuating motion of the phases are negligibly small; the change in internal energy of the powdered medium owing to the work of the interphase friction force occurs completely in the gas phase; the elastic component of internal energy of particles is a constant, and the thermal component depends on the work of forces of interparticle interaction (dry friction) and interphase heat transfer; the powdered medium has a viscoelastic skeleton with minor deformations; the gas phase is an ideal gas; there are no external mass forces; there is no heat transfer with the ambient medium; the contribution of the unsteady Basset force to the total force of interphase interaction is ignored, but the contribution of the unsteady force of added masses is taken into account; the motion of the gas and particles of the powdered medium is assumed to be one-dimensional, planar, and unsteady. Under the assumptions made, the governing equations of motion of the phases of the porous granular medium have the following form [29][30][31][32]:…”