Shear Layer Behavior Research Articles

Eddy Formation behind Circular Cylinders

Explanations of how and why eddies form in the wake of a cylinder in cross-flow are offered. Potential flow theory is used to demonstrate basic tendencies resulting from the behavior of shear layers and vortices under a variety of conditions prevailing in actual flows. Eddies shed alternately behind a cylinder and form Karman vortex streets, as a combination of vorticity emanating from the boundary layers and the instability of these layers due to the vorticity which they contain. Potential flow theory modeling gives useful predictions of flow about bluff cylinders. Shear layers are readily disintegrated by flow disturbances. The effects of vorticity in boundary layers on other regions apparently can be approximated by the effects of distributed finite vortices in the potential theory modeling of flow about cylinders.

Closure to “Discussions of ‘On Integral Methods for Predicting Shear Layer Behavior’” (1970, ASME J. Appl. Mech., 37, pp. 559–564)

Closure to “Discussions of ‘On Integral Methods for Predicting Shear Layer Behavior’” (1970, ASME J. Appl. Mech., 37, pp. 559–564)

On Integral Methods for Predicting Shear Layer Behavior

The origin and consequences of a nonphysical constraint which may arise when boundary-layer momentum integral equations are used to predict the behavior of shear layers are examined. It is pointed out that should the constraint occur within the domain of integration of the momentum integral equations, the effect may either be catastrophic or significantly constrain the solution. Several methods of solution having the usual advantages associated with boundary-layer momentum integral equations, but free from this constraint, are proposed for the specific problem of the plane turbulent near wake. One method developed to avoid this constraint in the case of a plane turbulent near wake appears to be perfectly general, and therefore, it may be possible to apply this method to both boundary layers and wakes.