Low room with non-uniform absorption (comparison with experimental data)

Description

Low room (8m x 30m x 3.85m) with non-uniform absorption, with a single source, 7 receivers along a line and a reference receiver.

All elements of this simulation are licensed under Licence Creative Commons Attribution 4.0 International License.

What is tested?

Comparison between SPPS and experimental data from [Ondet, 1989].

[Ondet, 1989] Ondet, A. M. , and Barbry, J. L. (1989). “ Modeling of sound propagation in fitted workshop using ray tracing,” J. Acoust. Soc. Am. 85(2 ), 787–796. doi.org/10.1121/1.397551

CAUTION - The following results present comparisons between numerical simulations carried out with I-Simpa and 'reference' data available in the scientific literature. However, it is difficult to prejudge the concept of 'reference'. The deviation between the simulations and the reference data that can be observed do not necessarily call into question the corresponding simulations but can also be associated with other sources of deviation (modeling assumptions, numerical instabilities, experimental uncertainties, etc.). In addition, some numerical models (like SPPS), based on random methods, may produce small deviations between two distinct simulations.

Results

Normalized sound pressure level

This figure shows the normalized sound level (relative to the source power level) for receivers from 3m to 27m (y-location) to the source (step of 3m) and a reference receiver. The SPPS code shows a very good agreement with the experimental data, with a mean deviation of 0.38 dB and a maximum deviation of 0.90dB, which must be compared with the uncertainties of measures, estimated by the authors at 1dB.

Calculation parameters

ParametersValue
Active calculation of Atmospheric absorptionYES
Active calculation of diffusion by fitting objectsNO
Active calculation of direct field onlyNO
Active calculation of transmissionNO
Calculation methodEnergetic
Limit value of the particle extinction5.0
Number of sound particles per source1 000 000
Number of sound particles per source (display)0
Random initialization number0
Receiver radius0.31
Simulation length (s)1.500
Time step (s)0.005