J. Stuart Bolton• Ph.D. Institute of Sound and Vibration Research, Southampton University, UK.
– Poroelastic materials and applied signal processing
• Professor of Mechanical Engineering– Wave propagation and sound radiation
– Sound Field visualization
– Poroelastic materials
– Noise Control
• Americas Editor (with Patricia Davis) of the Journal of Sound and Vibration
• Funding from: 3M, Sony, Cummins Engines, Boeing, Raytheon Aircraft . . .
Optimization of Acoustic TreatmentsOptimization of Acoustic Treatments3 foams , 2 air space, 3 panel3 foams , 2 air space, 3 panel
FOAM1
FOAM2
FOAM3
AIR1
AIR2
Panel 2 Panel 3Panel 1
Incidence 1
Tc Transmitted
Reflection Rc
Area I
Z=0 Z=L1
Z=L2
Z=L3
II
Z=L4
Z=L5
III IV V VI VII
Honeycomb panel
solve for
Area I inin jP 0
Area II
Area IV
zv inzin
654321 hhhhhh CCCCCC
trtr jP 0z
v trztr
Panel motion
xjktt
xeWW ~ xjkpp
xeWW ~
654321 pppppp CCCCCC
Area V
Area III 21 11 AA
Area VI
Area VII
654321 qqqqqq CCCCCC
21 22 AA
Apply b.c.’s at each interface
SEM – ThinsulateSEM – Thinsulate
B&K Four-mic TL tubeB&K Four-mic TL tube
[ Direct BEM ]
radiation field characteristicsbased on Acoustic Radiation Mode
(Acoustic Transfer Vector)
SPL & Sound Intensity on a hemisphere surrounding a tire
Sound Power Radiation Efficiency
Radiation Mode Contribution[ Structural Harmonic FEM ]structural wave propagation
based on surface normal velocities
Component Noise: e.g. Tire Radiation Component Noise: e.g. Tire Radiation Analysis ProcedureAnalysis Procedure
Frequency # of nodes
164 Hz 8 (n=4)
140 Hz 6 (n=3)
115 Hz 4 (n=2)
n 3
From Dispersion Curve
Acoustical Holography for Noise Source Identification: Acoustical Holography for Noise Source Identification:
e.g. rolling tire at 21 mph (128 Hz)e.g. rolling tire at 21 mph (128 Hz)