(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-10)
DiPerna, Daniel T.
This thesis investigates a new method for predicting the farfield scattered pressure of a
plane wave due to an infinite cylinder of noncircular cross section. Both impenetrable and
penetrable :fluid boundary condi tions will be treated for several types of cross sections
and for a large frequency range. This new method requires the conformal mapping of
both the exterior and interior of a closed surface to a semi-infinite strip. Numerically
efficient algorithms wi ll be presented for both of these cases.
A new method for satisfying the boundary conditions will be developed, as well
as an efficient algorithm for generating the required modal functions on the boundary.
Numerical results are presented for cross sections in the shape of an ellipse, square, and
three leaf clover. In all cases, the results compare extremely well with exact or high
frequency asymptotic results.
