Abstract
Laminar separation bubbles formed on airfoils were expressed numerically using a simple eddy-viscosity turbulence model. The eddy viscosity constant, εt, was set to a uniform value inside the turbulent part of the bubble. Overall characteristics of numerical results agreed closely with experimental results. The relation between εt and velocity distributions was analyzed by the momentum balance inside the bubble. It was shown that the pressure recovery inside the bubble is proportional to εt. Finally, the semi-empirical parameter which determines εt was proposed.