http://www.k-wave.org/forum/topic/plane-wave-propagation-in-a-layered-medium-with-different-material-properties Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 03:48:36 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/plane-wave-propagation-in-a-layered-medium-with-different-material-properties#post-4303 Sat, 08 Feb 2014 09:48:27 +0000 Bradley Treeby 4303@http://www.k-wave.org/forum/ <p>Hi Chiara,</p> <p>The best way to get started with k-Wave is to open the documentation in the MATLAB help browser, and work through the "Initial Value Problems" and "Time Varying Source Problems" examples one by one. You might also find Chapter 3 of the <a href="http://www.k-wave.org/documentation.php">k-Wave manual</a> helpful. After that, you should find creating the example you mention fairly straightforward.</p> <p>Good luck with your simulations,</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/plane-wave-propagation-in-a-layered-medium-with-different-material-properties#post-4300 Thu, 06 Feb 2014 10:43:14 +0000 meu06146 4300@http://www.k-wave.org/forum/ <p>I want to run a model allowing me to create a source in one layer with a specific frequency. I want to create sensors allowing me to model the change in peak particle velocity and frequency content of the signal as it propagates through the layers using sensors.</p> <p>Can you advise best how to do this using k-wave toolbox?</p> <p>Many thanks</p> <p>Chiara</p> <p>I have had a play around with the following example:</p> <p>clear all;</p> <p>% =========================================================================<br /> % SIMULATION<br /> % =========================================================================</p> <p>% create the computational grid<br /> Nx = 128; % number of grid points in the x (row) direction<br /> Ny = 128; % number of grid points in the y (column) direction<br /> dx = 0.1e-3; % grid point spacing in the x direction [m]<br /> dy = 0.1e-3; % grid point spacing in the y direction [m]<br /> kgrid = makeGrid(Nx, dx, Ny, dy);</p> <p>% define the properties of the propagation medium<br /> medium.sound_speed = 1500*ones(Nx, Ny); % [m/s]<br /> medium.sound_speed(1:Nx/2, :) = 1800; % [m/s]<br /> medium.density = 1000*ones(Nx, Ny); % [kg/m^3]<br /> medium.density(:, Ny/4:end) = 1200; % [kg/m^3]</p> <p>% create initial pressure distribution using makeDisc<br /> disc_magnitude = 5; % [Pa]<br /> disc_x_pos = 50; % [grid points]<br /> disc_y_pos = 50; % [grid points]<br /> disc_radius = 8; % [grid points]<br /> disc_1 = disc_magnitude*makeDisc(Nx, Ny, disc_x_pos, disc_y_pos, disc_radius);</p> <p>disc_magnitude = 3; % [Pa]<br /> disc_x_pos = 80; % [grid points]<br /> disc_y_pos = 60; % [grid points]<br /> disc_radius = 5; % [grid points]<br /> disc_2 = disc_magnitude*makeDisc(Nx, Ny, disc_x_pos, disc_y_pos, disc_radius);</p> <p>source.p0 = disc_1 + disc_2;</p> <p>% define a centered circular sensor<br /> sensor_radius = 4e-3; % [m]<br /> num_sensor_points = 50;<br /> sensor.mask = makeCartCircle(sensor_radius, num_sensor_points);</p> <p>% run the simulation<br /> sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor);</p> <p>% =========================================================================<br /> % VISUALISATION<br /> % =========================================================================</p> <p>% plot the initial pressure and sensor distribution<br /> figure;<br /> imagesc(kgrid.y_vec*1e3, kgrid.x_vec*1e3, source.p0 + cart2grid(kgrid, sensor.mask), [-1 1]);<br /> colormap(getColorMap);<br /> ylabel('x-position [mm]');<br /> xlabel('y-position [mm]');<br /> axis image;</p> <p>% plot the simulated sensor data<br /> figure;<br /> imagesc(sensor_data, [-1, 1]);<br /> colormap(getColorMap);<br /> ylabel('Sensor Position');<br /> xlabel('Time Step');<br /> colorbar; </p>