Analysis of airfoil leading-edge separation bubbles

Analysis of transitional separation bubbles on infinite swept wings

“…The corresponding reference displacement thickness distribution which also appears explicitly in the Cauchy integral analysis (see ref. 10) was obtained from a direct (attached flow) fully turbulent boundary layer calculation in which the inviscid reference solution was used for the prescribed boundary layer edge velocity component. The upstream velocity profile for the interaction calculation was .obtained from a direct laminar boundary layer calculation from the leading edge of the swept plate to a downstream position, x = 7.0 inches, which is upstream of the strong interaction region.…”

Analysis of airfoil transitional separation bubbles

“…(22) in the reversed flow regions are compared with the results presented by Carter and Vatsa (Ref. 21) using the same code but with the FLARE approximation.…”

“…21 and subsequently condensed into the paper in Ref. 22, an inverse finite difference boundary layer procedure was iteratively combined with a Cauchy integral representation of the inviscid flow which is assumed to be a locally linear perturbation to a known global viscous airfoil solution.…”

Direct Numerical Simulation of Unsteady Separated Boundary-Layer Flows over Smooth Backward-Facing Steps

“…For larger Reynolds numbers the numerical methods often fail to converge or are otherwise unable to yield meaningful solutions. Attempts have been made to apply these methods for the calculation of transitional separation bubbles [9,10] using empirical transition models to switch the solution from laminar to turbulent flow. However, these calculations have shown that the numerical solution is strongly dependent on the transition criteria used.…”