Submodel of rotational motions in gas dynamics

An invariant submodel of the equations of gas dynamics constructed on a one-dimensional subalgebra consisting of the sum of operators of rotation and translation in time is studied within the framework of the SUBMODELS program. The system of equations of the submodel is brought to symmetric form. Hyperbolicity conditions for the system are derived. Group analysis is performed and an invariant solution is considered. Isobaric flows are listed. For the simplest of them, characteristics and strong discontinuities are considered. Necessary conditions for existence of solutions without singularities on the axis are derived.