Piezoelectric devices are widely used as sources to generate sound waves or receivers to detect acoustic signals. In applications such as ultrasound imaging and nondestructive testing, the same transducer can be used as a transmitter to send a source signal and receiver to detect echoes. Modeling these devices often requires transient analyses with time of flight as output. Let’s discuss how to use the COMSOL Multiphysics® software to model a piezoelectric device as both a transmitter and receiver.

In 1880, Alexander Graham Bell wrote a letter to his father, saying: “I have heard articulate speech by sunlight! I have heard a ray of the sun laugh and cough and sing!” He was talking about his latest success, the photophone, which he called his “greatest invention” shortly before his death. The photophone did not revolutionize the field of imaging, but an unintended effect Bell noticed while developing it did…

A thorough analysis of a loudspeaker driver is not limited to a frequency-domain study. Some desirable and undesirable (but nonetheless exciting) effects can only be caught by a nonlinear time-domain study. Here, we will discuss how system nonlinearities affect the generated sound and how to use the COMSOL Multiphysics® software to perform a nonlinear distortion analysis of a loudspeaker driver.

Picture a classroom filled with students. At the front, a teacher discusses room acoustics, including the underlying theories and acoustics phenomena involved. To help students visualize these concepts, the teacher has created a simulation app. This app, which is accessible through a web browser, enables students to dynamically alter parameters and see the results, creating a vivid learning experience. At the Technical University of Munich (TUM), several such apps are already being used, providing benefits to teachers and students alike…

The boundary element method (BEM) is included in the Acoustics Module as a physics interface. This interface, available as of version 5.3a of the COMSOL Multiphysics® software, can be seamlessly combined with interfaces based on the finite element method (FEM) to model, for example, acoustic-structure interaction problems. This functionality expands the range of problems that can be solved with the Acoustics Module. Here, we look into the BEM functionality, examples, and BEM-specific postprocessing.

When modeling acoustic devices, it’s often enough to account for linear propagation alone, even though nonlinearities are always present. However, when the signaling amplitude reaches high levels in a design, nonlinear effects become important. Engineers can include nonlinear effects in simulations by taking advantage of the Nonlinear Acoustics (Westervelt) feature in the COMSOL Multiphysics® software, as demonstrated by an exponential horn example.

The main design goal for a loudspeaker array is to achieve wider sound coverage than a single speaker could provide. At the same time, the radiation pattern of the array must be indistinguishable from that of a single speaker. One method for producing radially distributed sound for multiple loudspeakers is with a Bessel panel. By analyzing a benchmark model of a Bessel panel system, engineers can optimize the design of loudspeaker arrays and other acoustics systems.

The Doppler effect, or Doppler shift, occurs when the movement of an observer relative to a source (or vice versa) causes a change in wavelength or frequency. Discovered by Austrian physicist Christian Doppler in 1803, this phenomenon is experienced in many different ways, such as when an ambulance passes you by and you hear an audible change in pitch. Using the COMSOL Multiphysics® software, you can model the Doppler effect for acoustics applications.

When a tuning fork is struck, and held against a tabletop, the peak frequency of the emitted sound doubles — a mysterious behavior that has left many people baffled. In this blog post, we explain the tuning fork mystery using simulation and provide some fun facts about tuning forks along the way.

Today, guest blogger René Christensen of GN Hearing discusses including thermoviscous losses in the topology optimization of microacoustic devices. Topology optimization helps engineers design applications in an optimized manner with respect to certain a priori objectives. Mainly used in structural mechanics, topology optimization is also used for thermal, electromagnetics, and acoustics applications. One physics that was missing from this list until last year is microacoustics. This blog post describes a new method for including thermoviscous losses for microacoustics topology optimization.