Evaluation of a Complete Wake Integral for the Drag of a Car-Like Shape

Maskell's approach for performing drag integrals in far-field fully-developed three-dimensional wakes has been extended for near-field application. The extended theory has been applied to wake survey data at two traverse stations involving a stalled wing, and an idealized car model tested over a fixed ground at two yaw angles. As a spin-off, cross-flow velocity vector plots have been resolved into vorticity-driven and source-driven components, which give added insight into complicated flows.

The new extension appears to work well in application to the test data, but correlations with balance measurements were compromised by fixed-floor flow problems. A limited review suggests that, while problems of wake definition may be soluble at zero yaw, changes in flow topology may negate comparable solutions with the model yawed. These difficulties are circumvented if a moving ground is employed.