Optimal system, invariant solutions and evolution of weak discontinuity for isentropic drift flux model

Inequivalent classes of similarity solutions for isentropic drift flux two phase flow model are obtained by using one dimensional optimal classifications. The optimality of this classification is shown in a constructive manner, i.e., by constructing various invariant functions including conditional and numerical invariants. Further, with the help of invariant solution, we discuss the evolution of weak discontinuity which displays the nature of the general solution.