On the quasi-gasdynamic system of equations with general equations of state and a heat source

The quasi-gasdynamic system of equations with a mass force and a heat source is well known in the case of the perfect polytropic gas. In the paper, the system is generalized for the case of general equations of gas state satisfying thermodynamic stability conditions. The entropy balance equation is studied. The validity of the non-negativity property is algebraically analyzed for the entropy production. Two different forms of notation are derived for its relaxation summands. Under a condition on the heat source intensity, the property is valid.