http://www.k-wave.org/forum/topic/air-water-reflection Support for the k-Wave MATLAB toolbox en-US Tue, 02 Jun 2026 08:03:24 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/air-water-reflection#post-6748 Fri, 08 Feb 2019 13:23:47 +0000 babakkh 6748@http://www.k-wave.org/forum/ <p>Hi,</p> <p>You might also include the pressure release acoustic boundary conditions in the source code.<br /> I have done in this paper:<br /> <a href="https://academic.oup.com/gji/article-abstract/216/1/545/5146453" rel="nofollow">https://academic.oup.com/gji/article-abstract/216/1/545/5146453</a></p> <p>Best regards, </p> <p>Babak </p> http://www.k-wave.org/forum/topic/air-water-reflection#post-6741 Thu, 31 Jan 2019 09:52:40 +0000 Rola 6741@http://www.k-wave.org/forum/ <p>Thank you. </p> http://www.k-wave.org/forum/topic/air-water-reflection#post-6731 Tue, 29 Jan 2019 22:06:31 +0000 Bradley Treeby 6731@http://www.k-wave.org/forum/ <p>Hi Rola,</p> <p>Adding attenuation will preferentially dampen the high frequencies, which in your case dampens the high-frequency oscillations in your simulation. Is the initial pressure distribution smoothed? If not, turning smoothing on could also help. </p> <p>If you want to the wave amplitude to be correct, then I'd suggest trying to be reasonably accurate for the attenuation in water. As the transmission into air is close to zero, I don't think the attenuation value for air matters.</p> <p>In general, modelling water-air interfaces is difficult with k-Wave due to the huge impedance mis-match. I normally recommend artificially increasing the density of air in the simulation to 10 or 100. The reflection coefficient will still be close to -1, but the simulation will converge for much lower points-per-wavelength.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/air-water-reflection#post-6706 Wed, 09 Jan 2019 22:31:26 +0000 Rola 6706@http://www.k-wave.org/forum/ <p>Hi there, </p> <p>I'm running a simple simulation with two media air and water. The air interface is around 1mm and water is around 2.4cm. When I run the simulation (using an initial pressure dx= dy = 100 um) without considering alpha coefficients, the reflection coming from air has spurious oscillations. Introducing a coefficient attenuation for water and air the reflection coming from air does not have oscillations at all. Nevertheless, I have tried with random values for the alpha_coeff. So, if I perform a simulation with an initial pressure do I need to be precise with alpha_coeff? If yes, what is right way to introduce the attenuation coefficient for two media?</p> <p>Best. </p>