Experimental parametric study of rectangular bodies with radiused edges in ground effect

The work presented here is the result of an effort by the authors to study and document the aerodynamic effect of varying aspect ratio, ground clearance, and underbody roughness for basic rectangular shapes with radiused edges in ground effect. Particular emphasis is placed on interpretation of wake flow survey results and the correlation to measured forces. A study of rectangular bodies in ground effect with different aspect ratios, varying ground clearances, and different levels of underbody roughness was performed in a wind tunnel experiment. Results of force measurements and wake surveys obtained using a seven-hole pressure probe system are analyzed. Results for drag and lift coefficient are presented and analyzed. Expanded interpretation of wake survey data is presented to assist in the development of physical rationale to explain the force results. Strong correlation between the wake flows and force results is demonstrated.