BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Acoustic scattering by coaxial cylinders with lined walls. - Nigel
  Peake (University of Cambridge)
DTSTART:20240704T091500Z
DTEND:20240704T094500Z
UID:TALK214951@talks.cam.ac.uk
DESCRIPTION:We (Ben Veitch & Nigel Peake) consider &nbsp\;the &nbsp\;noise
  &nbsp\;radiated &nbsp\;by two semi-infinite &nbsp\;coaxial circular &nbsp
 \;cylinders carrying (different) uniform axial &nbsp\;mean flows. The exit
  planes &nbsp\;are staggered axially by a &nbsp\;finite distance\, and the
  inner cylinder is either buried upstream or protrudes downstream.&nbsp\; 
 In earlier work (B. Veitch & N. Peake 2008\, Journal of Fluid Mechanics\, 
 613\, 275--307) we solved the problem with rigid walls\, &nbsp\;and we &nb
 sp\;now &nbsp\;extend this &nbsp\;work to allow for the presence of sound-
 attenuating &nbsp\; acoustic liners (specifically by lining the outer wall
  of the inner cylinder). The &nbsp\;key step in the solution is the factor
 isation of a 3x3 Wiener-Hopf matrix\, and different methods for completing
  this &nbsp\; factorisation are required in the &nbsp\;buried and protrudi
 ng cases\, and specificlly in the protruding case&nbsp\; Pade approximants
  are required . We present &nbsp\;results &nbsp\;for the &nbsp\;far-field 
 scattered &nbsp\;sound which demonstrate the effects of &nbsp\;wall lining
  in a &nbsp\;range of cases.&nbsp\;
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR