  In this paper, a supersymmetric extension of the polytropic gas dynamics
equations is constructed through the use of a superspace involving two
independent fermionic variables and two bosonic superfields. A superalgebra of
symmetries of the proposed extended model is determined and a systematic
classification of the one-dimensional subalgebras of this superalgebra is
performed. Through the use of the symmetry reduction method, a number of
invariant solutions of the supersymmetric polytropic gas dynamics equations are
found. Several types of solutions are obtained, including algebraic-type
solutions and propagation waves (simple and double waves). Many of the obtained
solutions involve arbitrary functions of one or two bosonic or fermionic
variables. In the case where the arbitrary functions involve only the
independent fermionic variables, the solutions are expressed in terms of Taylor
expansions.
