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• December 16, 2016 Create Date
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National Advisory Committee for Aeronautics, Technical Notes - Flow Characteristics Over a Lifting Wedge of Finite Aspect Ratio with Attached and Detached Shock Waves at a Mach Number of 1.40

A series of schlieren photographs and pressure distributions are
presented which show the effects of transition from an attached to a
detached shock at the leading edge of a finite—span, 8.20 wedge as the
angle of attack is increased. These data were obtained in the Langley
h- by h—foot supersonic tunnel at a Mach number of l.h0.

A knowledge of the mixed subsonic and supersonic flow region that
exists near the leading edge of a wing when the bow shock is detached
is of importance in the design of supersonic aircraft. The theoretical
calculations (refs. 1 to 10) and experimental investigations (refs. 11
to 18) which have been conducted appear to be restricted to the study of
detached shocks on models at zero angle of attack. References 1h, 16,
and 18, in particular, trace the transition from a detached to an attache
shock as the Mach number is increased.

Data pertaining to the transition from an attached to a detached
shock as the angle of attack is increased were obtained in the Langley
h— by h-foot supersonic tunnel during the course of an investigation
which had other primary objectives. The tests were made at a Mach nump
ber of l.h0 with a wedge airfoil having an 8.20 apex angle. The model,
which did not span the test section, was 16 inches wide and had a chord
of h.9 inches.

A series of schlieren photographs and pressure distributions
along the midspan of the forward portion of the model were
obtained through an angle-of—attack range from O0 to 110 in 10 incre—
ments. The resulting pressure data have been integrated to obtain sec-
tion aerodynamic coefficients at midspan and are presented with the
schlieren photographs to supplement existing data on the effects of
shock detachment. Some pressure data were measured in the three—
dimensional flow field of the wing tips and are applicable only to
wedges of the same aspect ratio as the test model.