Noise / Acoustics

Acoustic/Sound/Noise waves undergo reflection, refraction and diffraction in the real world when they come across medium of varying properties. Such properties must be addressed for accurate sound wave propagation. One of the applications is reduction of noise, which is an unwanted sound that disrupts human activities.

Some examples where Flow Analysis’ Wave Confinement (WC) methodologies can assist are:
  1. Aero-acoustics – solving for the noise generated due to interaction between turbulent fluid and structure such as noise generation from body-wake interaction (i.e., wind mill, helicopter, fan, etc.)

  2. Room acoustics – solving for the behavior of sound in closed space, which helps the designers to better engineer the acoustics in a room.

  3. Architectural acoustics – solving for noise suppression in building design that can accurately predict the noise levels, which can further assist designers to better engineer noise suppression.
Acoustic waves interact with structures such as walls of a closed room to produce echoes, which have to be reduced for a better acoustic room. These echoes (reflected waves) interfere with incident waves causing high pressure zones, which create inconvenience to the human ear. Keeping this in mind, a lot of measures have been taken to reduce the noise levels. It is difficult and expensive to test these measures in real-time and the need to use Computational Fluid Dynamics (CFD) methods arises. Many conventional higher order CFD schemes have been used to solve the classical wave equation that governs the acoustic wave propagation. Sound waves being very thin compared to the computational domain (an entire room or a building or an urban layout or an entire city) are difficult to be captured with higher order methods due to their inability to completely overcome numerical diffusion. On the other hand, the WC method derived from Vorticity Confinement can simulate sound wave propagation in any complex topographical layout with no numerical dissipation. It accomplishes all this with no need for adaptive grid schemes. More information on WC is provided here.