Presentation on theme: "J. Stuart Bolton Ph.D. Institute of Sound and Vibration Research, Southampton University, UK. –Poroelastic materials and applied signal processing Professor."— Presentation transcript:
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 Treatments 3 foams, 2 air space, 3 panel FOAM1FOAM1 FOAM2FOAM2 FOAM3FOAM3 AIR 1 AIR 2 Panel 2Panel 3Panel 1 Incidence 1 T c Transmitted Reflection R c Area I Z=0Z=L 1 Z= L2 Z= L3 II Z= L4 Z= L5 III IV V VI VII Honeycomb panel solve for Area I Area II Area IV Panel motion Area V Area III Area VI Area VII Apply b.c.’s at each interface
SEM – Thinsulate B&K Four-mic TL tube
[ Direct BEM ] radiation field characteristics based 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 Analysis Procedure
Frequency# of nodes 164 Hz8 (n=4) 140 Hz6 (n=3) 115 Hz4 (n=2) n 3 From Dispersion Curve Acoustical Holography for Noise Source Identification: e.g. rolling tire at 21 mph (128 Hz)