An Experimental Investigation of Separated Flow on a Light Twin Engine Aircraft

Force measurements, surface flow patterns and wake total pressure surveys have been obtained for a wing, wing--body, wing-nacelle and wing-body--nacelle configuration at typical pre-and post-stall angle of attack (10° and 16°), for a general aviation twin-engine airplane. The data includes separated regions and combined flow field models.

The results indicate the presence of highly three-dimensional separated regions above and beyond the surface at post-stall condition.

Based upon the present experimental data, combined flow field models have been proposed for each of the configurations, at the pre-stall (10°) and post -stall (16°) angle of attack condition. In all cases, the flow is shown to be forming turbulent three-dimensional separation bubbles. These flow models should provide some guidelines for future analytical modeling of separated flow associted with interfering bodies.