Verification and accuracy

Acoustic BEM results checked against analytical solutions

The cases cover exterior and interior domains, radiation and scattering, pressure, velocity and impedance boundary conditions, and low-to-high frequency behavior.

Primary benchmark

Radiation from a vibrating sphere

A monopole at (R/2, 0, 0) produces a nonuniform velocity boundary condition on a unit sphere. Benchmark models range from 588 to 14,520,000 DOF at ka=2 and 20.

Pressure contour on a vibrating sphere at ka 20

Boundary pressure

Computed pressure on the sphere at ka=20.

Pressure contour on a sphere and exterior field surface at ka 20

Exterior field

Boundary and field-surface pressure for the same radiation case.

V9 performance

Millions of unknowns on a laptop

Using four of twenty threads on an Intel Core i7-13800H laptop, the 14.52-million-DOF FMM case required 580.97 seconds at ka=2 and 1,102.88 seconds at ka=20 in the current V9 benchmark workbook.

These values supersede the older 15- and 20-minute wording previously shown on this page.

V9 sphere benchmark wall-clock time versus degrees of freedom

Radiation and interior fields

Frequency response and resonant behavior

Radiated pressure from a transversely oscillating sphere

Oscillating sphere

A 30,000-element dual-BIE FMM model is compared with angular and frequency-domain analytical solutions from 20–1000 Hz.

Interior pressure response at the center of a vibrating sphere

Interior vibrating sphere

FMM center-pressure results from 20–2000 Hz track the analytical response and its resonant peaks.

Scattering

Rigid and pressure-release surfaces

Rigid sphere, ka=20

10,800-element FMM model with a reported maximum polar-pressure error of 0.18%.

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Rigid sphere, ka=100

187,500-element ACA model with a reported maximum polar-pressure error of 3.21%.

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Soft sphere, ka=20

Pressure-release boundary case with a reported maximum polar-pressure error of 0.45%.

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Exterior field surface

Pressure contours show the incident and scattered-field interaction around the sphere.

View contour

Sources and boundaries

Interior source and impedance checks

Monopole and dipole in a cube

A 10,800-element rigid cube compares frequency responses at a field point with analytical monopole and dipole solutions from 20–500 Hz.

View pressure contour

Vibrating box channel

A 51,600-element ACA model at ka=100 reports less than 2% maximum pressure error along the channel axis.

Watch animation

Impedance tube

An 8,400-element FMM model at ka=30 reports 1.85% maximum pressure error against the analytical solution.

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High-frequency radiating box

The HFBEM predicts far-field SPL from 20–2000 Hz using less than 1% of the reported conventional-BEM CPU time for this case.

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Reproduce the verification workflow

Use the Verification Manual and included sample models to examine inputs, analytical references, and expected results.