Aerodynamic Performance of the Three-Dimensional Lifting Supersonic Biplane

Abstract

This paper investigates the aerodynamic performance of the three-dimensional lifting supersonic biplane and its sonic boom. Although the Busemann biplane is known to cancel the wave drag, it does not produce lift, either. A few decades later, the supersonic biplane airfoils with lift were reported. This paper extends their ideas to the threedimensional biplane. The aerodynamic performance was revealed by using computational fluid dynamics. The possibility of sonic boom mitigation due to shock wave interaction was demonstrated.chord length c root = root chord length c tip = tip chord length h = wing clearance M 1 = freestream Mach number n = arbitrary point S = reference area, b c ref s = staggering length t ==FS = wing thickness parallel to freestream x = chord length coordinate y = spanwise coordinate z = height coordinate = angle of attack, deg 1 = oblique shock wave angle from the leading edge of the lower wing, deg 0 1 = oblique shock wave angle from the leading edge of the lower wing projected on the cross section, deg 2 = oblique shock wave angle from the leading edge of the upper wing, deg 0 2 = oblique shock wave angle from the leading edge of the lower wing projected on the cross section, deg 3 = diffracted oblique shock wave angle from the leading edge of the lower wing, deg 4 = diffracted oblique shock wave angle from the leading edge of the upper wing, deg ?LE = oblique shock wave angle in the cross section perpendicular to the leading edge, deg = taper ratio, c tip =c root = sweepback angle at the leading edge, deg Subscripts lower = lower wing upper = upper wing

Unsteady Aerodynamic Characteristics of the Pitched Supersonic Biplane

“…Several new conceptual supersonic aircrafts adopting the Busemann theory have been proposed in recent years [3,4]. Kusunose and his group have carried out series of researches by utilizing both CFD methods and wind-tunnel experimental methods since 2004 and acquired many significant achievements [5][6][7][8][9][10][11].…”