The HLL method for solving the Riemann problem in compressible two-velocity media

The paper considers a system of equations of motion of a two-phase medium with phase equilibrium in terms of pressure and temperature. The spectral analysis of the system was carried out for a one-dimensional case. Approximate numerical solutions of the Riemann problem about the decay of an arbitrary discontinuity were constructed using the HLL method, using the calculated characteristic values. A comparison with a single-phase analog of the system is made.