Locally interactive laminar separation bubble mode

A semi-empirical laminar separation bubble model has been developed and incorporated into an airfoil design and analysis program. The generality and efficiency of this model have been achieved by approximating the local viscous/inviscid interaction, the transition location, and the turbulent reattachment process within the framework of an integral boundary-layer method. In particular, the whole bubble flowfield is found to depend on two empirically derived dimensionless parameters and on the transition location as calculated using linear stability theory. Comparisons of the predicted aerodynamic and boundary-layer characteristics with experimental measurements for several airfoils show excellent and consistent agreement for Reynolds numbers from 2 × 106 down to 1 × 10⁵.