Results of calculation of unsteady direct and degenerating swirl turbulent flows of liquids and gases in pipes and channels with short and extensive flow regions are presented. Swirled flow hydrodynamics is investigated in details in the area of inlet into the pilot section. In modeling of turbulent heat-and-mass transfer there used 2nd order closure schemes with differential equations for Reynolds stress tensor with original low-reynolds restricting base of k-L equations. Mechanisms of generation and development of reverse flows, degeneration and rearrangement of swirl flow into direct one are analyzed in broad range of governing parameters. Developed algorithm accuracy in prediction of local and integral parameter distribution of complicated swirl flows are illustrated by means of comparison with experimental data.