ABSTRACT Proposal Number: CTS-9613143 Principal Investigator: Spall, Utah State The objectives of this investigation, involving two universities, are: (i) To carry out complementary experimental and numerical research in order to explore the structure and dynamics of vortex breakdown in turbulent swirling flows; (ii) To elucidate the physics of the phenomena and provide archival-quality experimental data for the assessment and validation of CFD codes with anisotropic turbulence models and for current as well as future scientific and technological developments; (iii) To carefully assess existing phenomenological models; (iv) To develop an understanding of the consequences of turbulence on vortex breakdown for its intellectual challenge and technological applications in aerodynamics, in combustion, and in general, in the development of effective flow control strategies in devices employing swirl dynamics. It is intended that this study would lead to reliable computer codes which might be used for industrial research and design. This grant is for the numerical component. A matching grant was made to the Naval Postgraduate School for the experimental phase (CTS-9612528).