Fully Nonlinear Goertler Vortices in Constricted Channel Flows and Their Effect on the Onset of Separation
INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
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The development of fully nonlinear Gortler vortices in the high Reynolds number flow in a symmetrically constricted channel is investigated. Attention is restricted to the case of strongly constricted channels considered by Smith and Daniels 1981 for which the scaled constriction height is asymptotically large. Such flows are known to develop a Goldstein singularity and subsequently become separated at some downstream station past the point of maximum channel constriction. It is shown that these flows can support fully nonlinear Gortler vortices, of the form elucidated by Hall and Lakin 1988, for constrictions which have an appreciable region of local concave curvature upstream of the position at which separation occurs. The effect on the onset of separation due to the nonlinear Gortler modes will be discussed. A brief discussion of other possible nonlinear states which may also have a dramatic effect in delaying or promoting separation will be given.
- Fluid Mechanics