AcouS PROPA® Software

AcouS PROPA® software is a simple and adaptable tool that allows you through its applications to cover all areas of engineering acoustics :

  • Industry
  • Environment
  • Room acoustics

and can perform projected sound propagation calculations in confined spaces or outdoors.

Therefore this software allows you to access all three following types of forecast calculations :

  • Sound propagation calculations taking into account the transmission through the walls (results presented in the form of noise maps)
  • Calculations of spatial decay
  • Sound decay time calculations.

AcouS PROPA® is a modular tool that meets the specific needs of each user. If your needs change, it is possible to add additional modules at any time.

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Presentation of AcouS PROPA®

Software for modeling acoustic propagation in premises and outside

AcouS PROPA® software is a simple and adaptable tool that allows you through its applications to cover all areas of engineering acoustics :

  • Industry
  • Environment
  • Room acoustics

and can perform projected sound propagation calculations in confined spaces or outdoors.

Therefore this software allows you to access all three following types of forecast calculations :

  • Sound propagation calculations taking into account the transmission through the walls (results presented in the form of noise maps)
  • Calculations of spatial decay
  • Sound decay time calculations.
Sound propagation simulation - Workplace

Sound propagation simulation - Workplace

AcouS PROPA Modules

AcouS PROPA® acoustic software is articulated in different modules. All software features are thus related to each other. It is therefore possible to install additional modules at any time.

Details of the various modules available to you :

  • Commun core : Basic module for modeling 3D geometry, the creation of noise sources and the definition of calculation parameters.
  • Transparency walls : Calculated transmission through the walls, from the calculation of the power incident on the walls and their sound reduction index.
  • Spatial Noise Decay : Calculated spatial sound decay from reference sound sources, comparing measurements and calculations, calculating the slope between 3 and 24 meters.
  • Noise maps : Calculated noise map in color, in any plane or along a complex topography, with smoothing for a neat appearance.
  • Room acoustics : Calculations Tr Echogram, C80, D50, EDT, RASTI, STI calculations comparison measures.
  • Meteorological conditions influence : Calculations taking into account weather conditions in favorable and unfavorable conditions for propagation, by taking into account the state of the atmosphere (wind speed and wind direction, temperature gradient...)
Calculation model

AcouS PROPA® simulates sound propagation due to one more sources of noise in open or closed 3D environments.

AcouS PROPA® screenshot

AcouS PROPA® screenshot

Diffuse reflectance model

This software is based on the assumption of acoustic diffuse reflection in a wall according to Lambert's law and assumes that the intensity at any point in the space consists of the superposition of a direct component, i.e. the intensity emitted directly by the source component and a reverberant. The first term, easily ascertainable, is a free-field propagation of spherical waves whose theoretical model is well known. On the other hand the second term is more difficult to quantify. It requires the assimilation of the walls of the premises in triangular surface elements behaving as point sources of well-defined directionality.

In addition, this model takes into account the geometry of the room, material characteristics and positions of the source and receiver.

This method chooses the descriptive variables as power densities (homogeneous intensity) present on the walls. The mathematical process that governs their determination is a process called "Markovian" which asserts that the state of a physical phenomenon depends only on its previous statements directly. Thus, in our case, the power density present on a dS' wall element at a t instant depends only on those present on all other e dS' elements forming the space at t instants diminished by their travel time respectively.

The dS wall element behaves like a point source at its centroid. Its radiation is spherical and that in the upper half-space. Its directivity is of the form : Q (Ɵ) = 4 cos Ɵ

Before any acoustic simulation, a factor known as "shape" is computed and translated in the form of a matrix, the visibility between each sample of sides, or sources, or points of reception. This coefficient depends only on the number of samples and therefore the number of wall and surface samples.

Then from the characteristics of the noise source (power per band, directivity, position), the algorithm performs a complete energy balance between the samples and determines the power density received by each of them compared to others and the direct wave. This calculation obviously takes into account the absorption of the walls of the premises.

The intensity received at the receiving point then has two components. The first corresponds to the intensity direct from the source whose propagation is in free field and the second comes from the different surface elements dS involved in the process of diffuse reflection.

AcouS PROPA® acoustic software was developed on this model of diffuse reflection over the past twenty years and has been compared to measurements on several occasions with convincing results.

Model taking into account the diffraction

Taking into account the phenomenon of diffraction is a key element and not negligible, especially in open spaces. The algorithm is based on the theory of Maekawa.

Before any calculation af attenuation for a given source and receiver, the algorithm fills in the form factor of all possible paths between each source element, each "free" edge of the premises and each receiving element. The calculated routes are considered the shortest between each of these elements. For a given receiver, the algorithm then calculates the total attenuation provided by each of these routes. This attenuation is then subtracted at direct pressure to get the "diffracted" level received.

Examples

Industrial environment

AcouS PROPA® is unique acoustic software, with which it is possible to implement any type of calculation in a single model (room acoustics, premises acoustics, environmental acoustics), while fully retaining its data sources, geometries.

Industrial building mapping

Industrial building mapping

Spatial decay calculations, noise maps, signal to noise relationship, radiation through the walls, AcouS PROPA® has always had all the functions needed for this field of acoustic engineering.

In the environment

AcouS PROPA® is unique acoustic software with which it is possible to implement any type of calculation in a single model (room acoustics, premises acoustics, environmental acoustics), while fully retaining its data sources, geometries.

Whether an industrial project, a wind farm, an auditorium,...AcouS PROPA® calculates acoustic noise maps for outdoors and incorporates a unique optional calculation module in favorable and unfavorable conditions for propagation, taking into account wind speed and direction, atmospheric conditions (day and night,...)

Windturbines field propagation model

Windturbines field propagation model

Acous Propa : Indoor and outdoor acoustic model

Acous Propa : Indoor and outdoor acoustic model

Room acoustics

AcouS PROPA® is unique software with which it is possible ti implement any type of calculation in a single model (room acoustics, premises acoustics, environmental acoustics), while fully retaining its data sources, geometries

This module offers the user the ability to calculate key criteria such as C80, D50, EDT, Tr and echogram, with a temporal resolution of 1 ms. The comparison calculation-measures are facilitated by the import of measured decay time and pasted into a spreadsheet.

Room acoustic propagation model

Room acoustic propagation model

Indoor acoustic propagation model

Indoor acoustic propagation model

Example of decay calculation at 125Hz

Example of decay calculation at 125Hz

Webcast

1. Presentation AcouS PROPA English


AcouS PROPA® Training

Next training : to be determined


Training Objectives :

Provide participants with basix knowledge of the phenomenon of acoustic propagation and its modeling.

People concerned : :

Engineers and technicians working in the field of noise control at work or environmental noise.

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Maintenance & updates

Related services

  • A maintenance contract

This maintenance contract provides among other things : the maintenance of the software and the dongle, the delivery of software updates for free for holders of the maintenance contract, phone support, special discounts on other software....

  • Updates

Each year a new version containing additions or changes in the software is available.

  • Training and seminars

We regularly organize inter-company and intra-company training courses on the use of the software.

  • Day of information and exchange

Each year and each software program, at least one day of information and discussion is held with the users of such software.

  • Calculations on demand service

We can do calculations of acoustic simulations on request with the use of our software.

You can avail of these services free or at very favorable terms for an annual fee.

FAQ

You will find answers below to some questions you ask and which we hope give you the information you seek .

  • What is the meaning of "the assumption of diffuse reflection by walls" implementation in AcouS PROPA ?

    This is how the reflection on the walls (soil, buidings,...) is considered. Reflection is called "specular" when the wave is reflected with an angle equal to the angle of incidence (that is, for example, optics in a mirror). Our model takes into account a diffuse reflection, i.e. the energy reflected from a wall is re-emitted in all directions, via a coefficient of directivity angle-dependent re-emission. This is a hypothesis that best represents reality, particularly in the external environment, where all the important parameters with respect to reflection tend to generate a diffuse reflection (different materials, many kinks and bumps, uneven surfaces...).

  • Does the module "Calculation long-distance" take into account the compass ?

    Yes, this module known as "weather" is integrated in AcouS PROPA® and it calculates the influence of the wind rose through the inclusion of meteorological information attached to the calculation, such as the direction, wind speed, temperature, etc...

    The module "weather" affects the propagation of sound waves by bending them upwards (if the wind direction is opposite to the direction of sound propagation) or by pushing them down (if the wind and propagation of sound waves follow the same direction).

  • Is it possible to make calculations for wind turbines, industries and buildings ?

    Yes, AcouS PROPA® is capable of making calculations, whatever the nature of the site, open or closed (industrial, building or wind). The calculation of propagation is governed mainly by the strength and direction of sound sources, the direction and nature (absorption coefficient) of the walls and floor. You can make long distance calculations for a wind farm taking into account the influence of weather on the site.

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