G.R. Wickham: an appreciation

Radiation of sound from a semi-infinite rigid duct inserted axially into a larger infinite tube with wall impedance discontinuity

“…In its original form, the matrix Wiener-Hopf equation encountered in this work does not seem to be solvable by applying the known factorization methods. However, for l ≤ 0, it is shown that the pre multiplication by a suitable entire matrix, reduces the matrix Wiener-Hopf equation into a form for which the weak factorization method is applicable (see for example [16][17][18][19][20][21]). The solution contains two infinite sets of unknown coefficients satisfying two infinite systems of linear algebraic equations.…”

Flexural edge waves and Comments on “A new bending wave solution for the classical plate equation” [J. Acoust. Soc. Am. 104, 2220–2222 (1998)]

“…14 However, submerged plates support such waves only under very light fluid loading conditions: for instance, thin plates of aluminum, brass or Plexiglas will support edge waves in air, but not in water. 14 Previous studies of the flexural edge wave on a semiinfinite plate in vacuo have used either the Kirchhoff plate theory or some far more sophisticated analysis based on the full equations, e.g., FEM. We now demonstrate that the essential characteristics of the edge wave are captured by the Mindlin plate theory 15 without much additional effort beyond that required for the Kirchhoff theory.…”