3-DIMENSIONAL BLADE-VORTEX INTERACTION IN THE STRONG VORTEX REGIME

A study of three-dimensional interaction between a blade and an initia lly columnar vortex was performed using flow visualization experiments and computer simulations for problems where the blade is translated n ormal to and impacts upon the vortex core. The reported research focus es on cases where the vortex is sufficiently strong that the blade bou ndary layer separates before the blade penetrates into the vortex core . The study examines the topology and evolution of the separated secon dary vorticity from the blade and its interaction with the primary vor tex. In particular, it is observed that the separated vorticity from t he blade has the form of a series of vortex loops that wrap around the outer surface of the primary vortex core and spread both upstream and downstream along the vortex axis. Both the initial formation of these vortex loops and their eventual interaction with the primary vortex a re investigated. Computations based on a series of idealized models of the secondary vorticity are performed in order to examine the primary vortex response to wrapped vortex loops. (C) 1998 American Institute of Physics. [S1070-6631(98)00411-5].