Downwash and Wake Behind Untapered Wings of Various Aspect Ratios and Angles of Sweep

An investigation has been made in the Langley 7- by 10 foot tunnel to determine the downwash angles and the dynamic-pressure ratios behind wings of various sweep angles and aspect ratios, and the aerodynamic force characteristics of the wings. A brief discussion of some of the effects of the more important variables is presented. The wake center line behind swept forward wings was found to be located higher than the wake center line behind sweptback wings. A low tail position appears to be most stabilizing for all configurations investigated with the exception of the short tail length behind the unswept wing at an angle of attack of 160. At low tail positions and low angles of attack the rate of change of downwash angle with angle of attack increases as sweepback decreases. At high tail positions and high angles of attack the reverse tends to be true.