http://www.k-wave.org/forum/topic/parametric-acoustic-array Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:32:14 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-8555 Fri, 17 Jun 2022 15:08:24 +0000 bencox 8555@http://www.k-wave.org/forum/ <p>Hi songrock,</p> <p>When you say the sound pressure field is not correct, what are you comparing to?</p> <p>Best wishes<br /> Ben </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-8546 Sat, 04 Jun 2022 03:17:08 +0000 songrock 8546@http://www.k-wave.org/forum/ <p>Hi Felipe, </p> <p>I'm also working on the parametric acoustic array design, simulating 2D using this toolbox.<br /> Now the difference frequency can be got, but the sound pressure field from the difference frequency is not correct.Could you please share some advice about how to get the difference frequncy from the simulation calculation.<br /> Thanks so much. </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-7335 Mon, 30 Mar 2020 14:16:15 +0000 btj 7335@http://www.k-wave.org/forum/ <p>hello,<br /> can the current version of tool simulate acoustic parametric arrays? </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-6349 Sat, 17 Mar 2018 10:49:58 +0000 ffarias 6349@http://www.k-wave.org/forum/ <p>Hi Bradley,<br /> I took some time to reply as my code runs for some hours (or days!). After a few adjustments, by decreasing the time step, the sensors seem to record all data.<br /> Thank you for your help!</p> <p>Felipe. </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-6339 Sat, 10 Mar 2018 20:11:09 +0000 Bradley Treeby 6339@http://www.k-wave.org/forum/ <p>Hi Felipe,</p> <p>NaNs normally point to an instability. Have you tried decreasing the size of the time step?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-6334 Fri, 09 Mar 2018 03:49:25 +0000 ffarias 6334@http://www.k-wave.org/forum/ <p>Hi Bradley, thanks for your prompt reply.<br /> I had a look at the arrays and it actually shows results up to a certain grid point.</p> <p>Looking at 2 cases where this happens, results are shown up to 4704 (out of 10000) in one case, and 3314 for the other case, after those points is all NaNs. Correspondingly, the output h5 file size is half for the first case, and a third for the second one, when compared to the file which has the full data.<br /> Regards</p> <p>Felipe. </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-6333 Thu, 08 Mar 2018 12:18:00 +0000 Bradley Treeby 6333@http://www.k-wave.org/forum/ <p>Hi Felipe,</p> <p>Hard to say without seeing the complete code. When you say it doesn't record any pressure, do you mean the sensor data is all zero, or nans, or something else?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/parametric-acoustic-array#post-6331 Thu, 08 Mar 2018 10:34:25 +0000 ffarias 6331@http://www.k-wave.org/forum/ <p>Hi,<br /> I am simulating the parametric acoustic array in air using the C++ code. My source is a modulated sinusoid, the code runs well but it does not record any pressure, depending on the modulation I use.<br /> For example, if I use double side band modulation, everything is ok, but if I use quadrature amplitude modulation, no results are found in the pressure array. This is the code for generating quadrature amplitude modulation:</p> <p>Sc1=A*sin(2*pi*fc*t);%Carrier Signal 1<br /> Sc2=A*cos(2*pi*fc*t); %Carrier signal 2</p> <p>%% QAM<br /> g1=(1+mi*g); %envelope 1 DSBAM<br /> g2= sqrt(1-(mi.^(2)*g.^(2))); %envelope 2 </p> <p>Sfm=(g1.*Sc1) + (g2.*Sc2);%QAM</p> <p>For double side band modulation only the first term is used (g1.*Sc1). I tested both sources in a very small grid and it does work, so I don't know what happens in a bigger grid. In both cases the signal Sfm is multiplied by 5.</p> <p>When I decrease to 1/5 of the amplitude of the source the problem seems to be solved (pressure is found in the array), but as I need to generate some nonlinear effects, the expected harmonics are gone, so it is not useful for me.</p> <p>Do you have any idea what can be the problem?<br /> Regards</p> <p>Felipe. </p>