BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:Isaac Newton Institute Seminar Series
SUMMARY:Adaptive High-order Finite Volume Discretizations
on Spherical Thin Shells - Phillip Colella\, (La
wrence Berkeley National Laboratory)
DTSTART;TZID=Europe/London:20120925T113500
DTEND;TZID=Europe/London:20120925T120000
UID:TALK40091AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/40091
DESCRIPTION:We present an adaptive\, conservative finite volum
e approach applicable to solving hyperbolic PDE's
on both 2D surface and 3D thin shells on the spher
e. The starting point for this method is the equia
ngular cubed-sphere mapping\, which maps six recta
ngular coordinate patches (blocks) onto the sphere
. The images of these blocks form a disjoint union
covering the sphere\, with the mappings of adjace
nt blocks being continuous\, but not differentiabl
e\, at block boundaries. Our method uses a fourth-
order accurate discretization to compute flux aver
ages on faces\, with a higher-order least squares-
based interpolation to compute stencil operations
near block boundaries. To suppress oscillations at
discontinuities and underresolved gradients\, we
use a limiter that preserves fourth-order accuracy
at smooth extrema\, and a redistribution scheme t
o preserve positivity where appropriate for advect
ed scalars. By using both space- and time-adaptive
mesh refinement\, the solver allocates comp utati
onal effort only where greater accuracy is needed.
The resulting method is demonstrated to be fourth
-order accurate for advection and shallow water eq
uation model problems\, and robust at solution dis
continuities. We will also present an approach for
the compressible Euler equations on a 3D thin sph
erical shell. Refinement is performed only in the
horizontal directions\, The radial direction is tr
eated implicitly (using a fourth-order RK IMEX sch
eme) to eliminate time step constraints from verti
cal acoustic waves. \n
LOCATION:Seminar Room 1\, Newton Institute
CONTACT:Mustapha Amrani
END:VEVENT
END:VCALENDAR