Pipe Flow Module Updates

For users of the Pipe Flow Module, COMSOL Multiphysics® version 5.5 brings a new physics interface to perform stress analysis in pipe systems, a new multiphysics coupling to couple pressure acoustics to pipe acoustics, and an automatic search for T- and Y-junctions in a pipe system. Read more about these features below.

Mechanical Analysis of Pipes

The new Pipe Mechanics interface provides functionality for performing stress analysis of pipe systems. In addition to external mechanical loads, you can account for internal pressure, axial drag forces, and temperature gradients through the pipe wall. The fluid loads can be taken directly from the Pipe Flow interface, and the temperatures can be taken from the Heat Transfer in Pipes interface. You can see this new interface in the Coupled Analysis of Flow and Stress in a Pipe model.

Three modeling results for a piping system showing pressure and velocity as arrows and blue-white gradient, temperature as a red-yellow gradient, and stress as rainbow coloring.
Results from a coupled flow, heat transfer, and mechanical analysis in a piping system: pressure and velocity (left,) temperature (middle), and stress with exaggerated deformation (right).

Acoustic-Pipe Acoustic Connection Multiphysics Coupling

With the new Acoustic-Pipe Acoustic Connection multiphysics coupling, you can couple the pressure acoustics interfaces to the pipe acoustics interfaces in both frequency and time domain simulations. The coupling is defined between a point in the pipe interface and a boundary in the pressure acoustics interface. You can see this functionality used in the Probe Tube Microphone and Acoustics of a Pipe System with 3D Bend and Junction models.

The COMSOL Multiphysics UI with the Settings window open for the Acoustic-Pipe Acoustic Connection multiphysics coupling and a pipe system model in the Graphics window.
Use of the new Acoustic-Pipe Acoustic Connection multiphysics coupling in the Acoustics of a Pipe System with 3D Bend and Junction tutorial model.

Automatic Selection of T-Junctions and Y-Junctions

The software can now automatically add T- and Y-junctions in your pipe system to the selection, based on the angles between the branches in a junction. This significantly simplifies the modeling of large pipe networks, as you do not need to select the points manually. The default is still a manual selection, but you can uncheck a new Manual control of selections box, and the software will add the appropriate points to the selection. You can also check the Enable physics symbols box in the Pipe Flow interface node to view the symbols in the Graphics window.

The Settings window for a T-junction is shown with the Manual control of selections box unchecked and a sprinkler system model in the Graphics window.
By unchecking the Manual control of selections box in the Selection Settings section, T-junctions will automatically be added to the selection.

A model of a sprinkler system visualizing pressure and fluid velocity with arrows and a blue gradient.
Pressure and fluid velocity within a sprinkler system.

New Tutorial Models

Version 5.5 brings three new tutorial models.