Calculation technology

CadnaR allows you to choose the calculation strategy from a selection of scientific and highly efficient calculation methods. Depending on the selected method, acoustical effects such as the absorption, scattering or transmission on any obstacle are taken into account.

Further performance improvements are based on up-to-date and innovative technologies. This includes a true native 64-Bit version and the possibility to use the processing power from your graphics card in your project.

The particle model

With the particle model, a large number of "sound particles" are emitted randomly from each source location into all room directions. This method is applicable to any room shape and any shape of obstacles inside the room. The acoustic properties (absorption, specular and diffuse scattering) of room surface and obstacles determine the course and the energy of each individual particle. Emitting thousands or millions of particles and knowing the position and energy of any particle at any point in time allows to deduce sound pressure levels and other acoustic properties like reverberation time and STI at any receiver position. Additionally, diffraction at obstacles and transmission through obstacles is supported within the particle model.

The image source model

With this method, reflections occurring at the room surfaces and at obstacles (also at reflecting sources) are modeled by rays. Each ray path is tracked individually considering reflections from obstacles and the room surfaces up to the specified order of reflection. The image source model takes into account absorption properties and diffraction, but has limitations in handling scattering (only specular reflections), does not support transmission and cannot handle complex objects like the polymesh.

Additional calculation methods*

Besides the main methods described above, CadnaR also features additional calculation methods used for specific applications:

  • VDI 3760: the procedure described in the guideline VDI 3760 is based on the image source method with diffraction and damping according to Kuttruff and Jovicic.
  • Statistical Method: this calculation method calculates the sound pressure level according to the statistical theory of the reverberation in rooms by Sabine.

* Option CALC required

Faster calculations supported by your graphics card

Fast calculation times are essential for any simulation software. CadnaR supports the NVIDIA’s CUDA API* to dramatically speed up the calculation when the particle model is used. This way, Graphic Processing Units (GPUs) replace CPU´s to compute calculation intensive applications a parallelized and very efficient way.

*Option ORG and a computer equipped with a NVIDIA GPU required