This post is just a small one; I was playing around with acoustic topology optimization, and inspired by the Acoustic Demultiplexor, I had an idea about having two inputs, each of them assigned to each their output, without any explicit 'tubing' being possible for this 2D case. At one input a certain frequency is input, and at the other input another frequency is input. I want the sound to 'cross' the quadratic design domain, from lower input to higher output, and vice versa. First an animation before running the topology optimization:

The colors show the sound pressure, and the arrow indicate the intensity. Note how the sound to a large degree goes out the other input, and not just the two outputs, making the optimization a little more complicated. Nevertheless, the optimization routine can be set up in COMSOL Multiphysics, and the results are show below.

The optimized design does what it is supposed, i.e. sound has found a way to cross across the geometry by means of simply putting some blockage in the design domain. Very fascinating. Do you have other ideas for Acoustic Topology Optimization or other comments? Let me know below or write me an email at info@acculution.com.