Analytical two-dimensional solutions for hydrodynamic astrophysical flows

A new class of steady state, analytical, two-dimensional, non-separated variables solutions for helicoidal hydrodynamic (HD) outflows from rotating stellar objects is derived selfconsistently from the set of the governing (Eulerian) equations of continuity. The fluid is assumed to be compressible, inviscid and non-polytropic. The families of solutions describe either accelerating or decelerating stellar winds with weak collimation (quasi-spherical) which vanishes with the radial distance. We present four cases of solutions with their velocity maxima either at the poles or at the equator of the central body and some of them can be understood as inflows or as stellar shell formations. One of the solution families, showing an accelerating supersonic outflow, is applied to typical parameters of T Tauri stars keeping the observational outflow velocities and mass loss rates. Under this example, the applicability of these solutions is examined. The new solutions are compared with previous analytical 2-D models.