Enskog and Enskog-Vlasov equations with a slightly modified correlation factor and their H theorem

A novel modification of the original Enskog equation is proposed. The modification is much simpler than that is made in the modified (or revised) Enskog equation proposed by van Beijeren & Ernst in 1973 and does not require a consideration of many-body configuration. The proposed modification is general enough to be adapted to various equations of states for non-ideal gases. It is shown that the H-theorem can be established for the Enskog and the Enskog–Vlasov equation with the proposed modification.