Unsteady conditions of cooling of the porous fuel element

The unsteady gas flow throw porous fuel element is considered. The system of the equations, simulating this process, is solved by the finite difference method. The problem of slump of gas pressure on the entrance of the fuel element from the steady conditions of cooling is considered. Two cases are investigated: 1) slumping of pressure to the value above the critical point, by which the new steady condition of cooling is available; 2) slumping of pressure to the value below the critical point, by which the new steady condition of cooling is not available. In the first case the new steady condition of cooling is established, but in the second case unlimited heating of fuel element takes place. Then the problem of periodic oscillation of gas pressure on the entrance of the fuel element is considered. In this case all state parameters are oscillated.