Abstract:
We use a new version of the conditional symmetry method to obtain rank-$k$ solutions expressed in terms of Riemann invariants of the isentropic compressible ideal fluid flow in $3+1$ dimensions. We describe
the procedure for constructing bounded solutions in terms of the elliptic Weierstrass $\wp$-function in detail.
Keywords:Riemann invariant, conditional symmetry method, rank-$k$ solution, system of hydrodynamic type.