Aerodynamics of Slender Bodies
Sometimes we are not interested in generating lift, just reducing drag, and when
we have to reduce the drag of a given volume, the best shape is often a slender
body -- and often nearly a body of revolution. The aerodynamics of such shapes
is quite different from airfoils and wings, but follows some of the the same
basic principles.
Bodies including fuselages are important because they
produce drag, lift and moment. They also produce important interference effects
with wings and substantially change the stability of an airplane.
The
flow over more general fuselages and bodies can be predicted in much the same
way as the flow over airfoils and wings. Superposition of sources and doublets
in the form of panel methods or simpler forms (ala thin airfoil theory) are
often used. Navier Stokes equations are used when flow separation is
suspected.
In the first part of this section, we examine the results of
such calculations rather than the methods themselves, while the second part
briefly introduces the concept of slender body theory.
Flow over
Bodies
Slender
Body Theory