Case Study

Some case studies and articles of user interview are introduced here.


Case 1.Sound radiation from sphere with vibrating part (Comparison with theoritical solution)

To see large image, click this.

To investigate the accuracy of WAON, we did a sound radiation analysis from spherical object which has a vibrating panel.
As a result, we can compare the theoritical result and result by WAON.

Model specification
Radius 0.125(m)
Angle α 11.5(Deg.)
Velocity 1(m/s)
Distance r 0.25(m)
Angle θ 0.90(Deg.)
Sound speed 340(m/s)
Medium 1.225(kg/m3)
Elems. 79,200
Nodes. 79,202

Case 2.Radiation analysis from vibrating engine of motor cycle

Elements : 42,512
Nodes : 21,076

Using result of vibration analysis by FEA software, sound radiation analysis from engine was done.
In such a case, because the mesh for FEA is typically finner than mesh needed for acoustic analysis, we have to prepare coarsener mesh for acoustic analysis.
But using WAON, we don't have to coarse a strucutural mesh for acoustic analysis in some case.

Frequency (Hz) Required Memory(GB) CPU Time (s)
3,000 2.7 1,504
4,500 3.1 3,474

* Using conventiona BEM approach, 100MB RAM is needed for this analysis

Case 3. Calculation of HRTF(Head Related Transfer Function) in full audible frequency range

(Analysis frequency: 20kHz,
DOFs of analysis model: 200,000,
CPU Time: about 1 hour)

This shows application for calculation of HRTF that is over 20kHz.
At such high frequency range, conventional BEM could not be available as the DOFs become huge. On the other hand, WAON can deal with such a high frequency range efficiently using FMBEM solver.
(The DOFs of the analysis model: 200,000, The CPU Time: about 1 hour)

Case 4. Acoustic analysis inside Car Cabin

DOFs of analysis model 48,586
Analysis frequency 1KHz
CPU Time 1.4 Hour

This is a application for room acoustic.
As the sound source, loudspeaker was modeled. Actually, vibration was defined on the panel at the position of loudspealer.
Using conventional BEM, it was difficult to calculate audible frequency range because the DOFs of the analysis model is huge. In this examples, as the DOFs is 48,586, conventional BEM needs about 36GB memory to solve the problem. On the other hand, using WAON, you can calculate the same problem with about 1.1 GB memory. It is very reasonable.

BEM Type Required Memory Required specification of PC
Conventional BEM 36.0GB Not available on 32bit/2GB PC
FMBEM (WAON) 1.1GB Available on 32bit/2GB PC

Case 5. Acoustic-structural coupled analysis

Acoustic-structural coupled analysis enables acoustic analysis in a wide variety of applications, including speaker diaphragms, for which acoustic analysis is required to have a highly precise model of the acoustic-structural interaction, and automobile intake manifolds or compressors that require transmitted noise issues to be addressed.

Prior to acoustic-structural coupled analysis, it is necessary to separately perform structural eigenvalue analysis using general structural analysis software. With WAON, the results of analysis may be read via a unique interface to generate a structural model for coupled analysis.

The chart is the example of analysis of the acoustic-structural interaction on the speaker diaphragm. By taking into consideration both acoustic resonance and the resonance of the diaphragm, analysis with higher precision is achieved.
(Red: coupled; Pale blue: uncoupled)

WAON User Interview

Yamaha Corporation

"Without WAON, the software enabling large-scale model analysis, and without our technology for feeding back the WAON analysis results into product development, this development would not have been possible."
-WAON large-scale acoustic analysis was instrumental in development of an audio system based on the world's first HRTF with full 24kHz coverage-