2 Replies Latest reply on Nov 30, 2012 10:06 AM by Eelco Brun

    Using a heat radiation source to model sound propagation

    Eelco Brun

      I have a rather simple situation in which there is a sound source in a chamber with 2 openings.

      And I would like to see how adaptations to the chamber size effect the sound coming out.

       

      To my surprise flow simulations does not have a sound function..

       

      SO I was wondering if it might not be possible to adapt a heat radiation source model, to model the effects of sound.

      As heat reacts quite similar to sound (travels in waves, reflects/absorps)

      I could perhaps, adapt the environment and materials to fit this situation in an external analysis?

       

      As it pertains only to heat, I could easily create new materials which mirror the reflectivity/absorption rates of the materials from heat to sound.

       

      I am however having trouble with adjusting the environment (gas-air) to reflect the decay rate of sound propagation of 0,159 dB/m.

       

      Can anyone help me troubleshoot this? or give their 2-cents about if and how this is going to work?

       

      (I am aware that I will not be able to factor in all the effects of sound, diffraction should translate to heat, I think..

      Interference (constructive of destructive) will propably not be calculated, or am I wrong to assume that?.)

       

      The situation is mainly about air born sound waves, contact sound will be more/too difficult to simulate.)

        • Re: Using a heat radiation source to model sound propagation
          Bill McEachern

          Sim Flow uses a ray tracing algorithim to model the progation of gray body radiation to compute view factors to enable the computation of the radiant heat transfer. I am not a sound guy so not sure if this approach can lead to a sensible approximation or not however no wave modeling is done so that part is out so any wave interactions will not be modeled - just reflection in my estimation and even then you only get to set one emssivity value (0 to 1). Effects that could be approximated by rays might have a chance such as bulk energy (1/R^3 decay). It all seems a stretch though at first blush. Also the fluid volumes are non absobing so decay due to medium damping won't be modeled either. In the HVAC module you can get spectral sensitivities and absorption in solid materials but it still seems a stretch. You should consult the tecnical reference to see if the details of the energy handling will provide any kind of sensible approximation.

            • Re: Using a heat radiation source to model sound propagation
              Eelco Brun

              First of all, thank you for your reaction.

               

              The ray tracing model should be sufficient for my/most modelling, as the soundsource creates a composite soundwave, and not a pattern with a clearly distinguishable major frequency/wavelength.

              Wave interaction is not (yet) my main problem (though I am curious to see if there are options for this for later on)

               

              Setting an energy decay rate at the source might work, had not thought about that, wil give that a try and get back if this works.