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UID:0-490@aerospace.technion.ac.il
DTSTART;TZID=Asia/Jerusalem:20151118T163000
DTEND;TZID=Asia/Jerusalem:20151118T173000
DTSTAMP:20230603T192014Z
URL:https://aerospace.technion.ac.il/events/fictitious-sources-method-for-
noise-level-analysis-from-an-aircraft-flying-at-a-given-altitude-above-a-g
round-with-variable-impedance-and-topography/
SUMMARY:Fictitious Sources Method for Noise Level Analysis from an Aircraft
Flying at a Given Altitude Above a Ground with Variable Impedance and Top
ography
DESCRIPTION:Lecturer:Yohan Kamoun\n Faculty:Department of Aerospace Enginee
ring\n Institute:Technion – Israel Institute of Technology\n Location:Cl
assroom 165\, ground floor\, Library\, Aerospace Eng.\n Zoom: \n Abstract:
\n Details: \n The analysis of noise level emanating from a distant sourc
e is needed in a number of applications\, most notably in environmental en
gineering. The sound pressure level (SPL) distribution is desired\, e.g.\,
due to the acute effects of sound on community. To this end\, one has to
solve a typically large-scale acoustics problem: a moving source over grou
nd with given impedance and topography.\nSince the human hearing bandwidth
is quite wide\, one has to repeatedly solve the Helmholtz equation in the
upper half space for many different wave lengths\, with given impedance b
oundary condition imposed on the ground. To this end\, an efficient Helmho
ltz equation solver must be used.\nIn recent years\, fictitious source met
hods (FSM) have been developed and applied for various problems such as ac
oustic and electromagnetic wave problems. For a flat ground with a zero or
infinite impedance\, basic fictitious source implementation can easily gi
ve a semi-analytical solution to the Helmholtz problem using the mirror im
age method. For a variable impedance or for ground with given topography\,
the problem becomes much more complex\, and a numerical solution is requi
red. The use of the FSM was previously proven to be efficient for the case
of a flat ground with a constant impedance.\nIn this Seminar we will pres
ent an extension to the previous work in the following main aspects:\n\n\n
The ground impedance may be a function of location.\n Topography: the gro
und may be non-flat\n\nIn contrast to the previous works\, where only the
residual was calculated\, it is now possible to evaluate the true error ge
nerated by the fictitious source method using a dedicated algorithm.
CATEGORIES:Seminars
LOCATION:Classroom 165\, ground floor\, Library\, Aerospace Eng.
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DTSTART:20151025T010000
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