Englewood Cliffs, Prentice-Hall, (1964) 120 p.

(Foundations of Modern Political Science Series)Public opinionBc/So11ERRORMISSING26

High Reduced Frequency Measurements on Airfoils with a Cavity

The influence of a cavity on the dynamical plunging behaviour of an airfoil is investigated by means of local unsteady pressure measurements, hot-wire anemometry and flow visualisations. At low Reynolds numbers (O(104)), flow visualisations and hot-wire measurements indicate the presence of shear layer instability modes of the shear layer above the cavity. At high Reynolds number (O(105)) the shear layer is turbulent and does not display any natural oscillatory modes. In an unsteady flow, generated by external forcing, no significant effect of the cavity, on the local unsteady pressure difference, is observed in the range of reduced frequencies tested. The pressure differences over the airfoils are dominated by the added mass of the airfoil