• Version
• 49 Downloads
• 2.03 MB File Size
• 1 File Count
• January 17, 2017 Create Date
• January 17, 2017 Last Updated

National Advisory Committee for Aeronautics, Technical Notes - Wing Body Interference at Supersonic Speeds with an Application to Combinations with Rectangular Wings

An exact theoretical method is developed that permits the determina—
tion of the pressure field of a wingAbody combination having a circular
body and a wing with supersonic leading and trailing edges. Detailed
calculations have been performed for wing4body combinations composed of
rectangular wings mounted at incidence on bodies at zero angle of attack
for effective chord—radius ratios of h or less. For large effective
chord-radius ratios some asymptotic results have been obtained. It was
determined that for the family of combinations having an effective chord-
radius ratio of A the area of the wing blanketed by the body does not
generate any lift itself but rather acts to support the lift generated
by the exposed wing, and that the body is less than 50 percent effective
in reflecting lift back to the wing. For chord—radius ratios less than A,
the relative amount of reflection increases.

The significant fact was determined that for rectangular wing—body
combinations for which the effective chord—radius ratio is greater than A,
most of the loss of lift due to interference can be estimated from the
first term of the Fourier series used in the analysis. This fact was
used to determine asymptotic lift results for the region where no exact
calculations were made. The asymptotic expressions, together with the
calculations, allowed the construction of design charts showing the lift
and center-of-pressure location of the exposed wing panels as a function
of effective aspect ratio and effective chord-radius ratio. The charts
show that as a result of interference the lift on the exposed wing panels
in combination with the body can be reduced as much as 15 percent below
the value for the wing panels Joined together, and that the center of
pressure of the exposed wing panels can move forward as mueh as h percent
of the wing chord.

In recent years the problems of supersonic wing-body interference
have occupied the attention of many workers in aerodynamics. The large
amount of effort expended on the subject is a result of the important
effects that interference can have on the over-all aerodynamic character-
istics of winngody combinations. The trend toward using large bodies
and small wings at supersonic speeds, especially for missiles, is the
prime reason for the increased importance of wing-body interference at
these speeds.