http://www.k-wave.org/forum/topic/acoustic-impedance-as-back-matching-layer Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 23:10:30 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/acoustic-impedance-as-back-matching-layer#post-6910 Tue, 25 Jun 2019 06:34:26 +0000 Bradley Treeby 6910@http://www.k-wave.org/forum/ <p>HI binpersonal.</p> <p>Are these the values you used for the simulation? If so, the density should be in units of kg/m^3. </p> <p>When using the transducer class, the sound speed is the one used to calculate the beam forming delays.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/acoustic-impedance-as-back-matching-layer#post-6880 Tue, 11 Jun 2019 17:45:48 +0000 binpersonal 6880@http://www.k-wave.org/forum/ <p>Hi, Brad,</p> <p>I also want to ask is there a way to simulate several different thickness of matching layers? </p> <p>I tried a few times with impedance and density of several matching layers as following, there are long ringing in the waveform and it is very difficult to converge even after I use very small time step and grid. </p> <p>And which sound speed should I use for transducer at grid row 1 ? the speed of piezoelectric material or the speed for beam-forming (c0)? </p> <p>%Matching Layer 1<br /> sound_speed_map(2:4,:,:) = 3900;<br /> density_map(2:4,:,:) = 2.02;</p> <p>%Matching Layer 2<br /> sound_speed_map(5:6,:,:) = 2608;<br /> density_map(5:6,:,:) = 1.173;</p> <p>%Lens<br /> sound_speed_map(7:25,:,:) = 1050;<br /> density_map(8:25,:,:) = 1.335;</p> <p>% properties used to derive the beamforming delays<br /> transducer.sound_speed = c0; % sound speed [m/s]</p> <p>Thank you very much! </p> http://www.k-wave.org/forum/topic/acoustic-impedance-as-back-matching-layer#post-5808 Wed, 04 Jan 2017 14:46:25 +0000 Bradley Treeby 5808@http://www.k-wave.org/forum/ <p>Hi hang,</p> <p>What do you mean by k-Wave crashed? Did you receive an error message?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/acoustic-impedance-as-back-matching-layer#post-5786 Sun, 11 Dec 2016 09:23:00 +0000 hang 5786@http://www.k-wave.org/forum/ <p>Hi, </p> <p>I'm trying to simulate a transducer with matching layer at front &amp; at back. When I increase the impedance to 1.8MRayls, k-wave crashed when using 20MHz frequency at 1300 m/s medium.</p> <p>Anybody has the similar experience?</p> <p>Many thanks!</p> <p>Best, </p>