# Application Gallery

The Application Gallery features COMSOL Multiphysics tutorial and demo app files pertinent to the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use tutorial models and demo apps with step-by-step instructions for how to create them yourself. The examples in the gallery serve as a great starting point for your own simulation work.

Use the Quick Search to find tutorials and apps relevant to your area of expertise. Log in or create a COMSOL Access account that is associated with a valid COMSOL license to download the MPH-files.

### Automotive Muffler

This model simulates the pressure wave propagation in a muffler for a combustion engine. It uses a general approach for analysis of damping of the propagation of harmonic pressure waves. The model is solved in the frequency domain and provides efficient damping in a frequency range of 100-1000 Hz.

### The Blasius Boundary Layer

The incompressible boundary layer on a flat plate in the absence of a pressure gradient is usually referred to as the Blasius boundary layer. The steady, laminar boundary layer developing downstream of the leading edge eventually becomes unstable to Tollmien-Schlichting waves and finally transitions to a fully turbulent boundary layer. Due to its fundamental importance, this type of flow has ...

### Laser Heating of a Silicon Wafer with Ablation

When modeling a manufacturing process, such as the heating of an object, it is possible for irreversible damage to occur due to a change in temperature. This may even be a desired step in the process. With the *Previous Solution* operator, we can model such damage in COMSOL Multiphysics. Here, we will look at the “baking off” of a thin coating on a wafer heated by a laser.

### Pacemaker Electrode

This model illustrates the use of COMSOL Multiphysics for modeling of ionic current distribution problems in electrolytes, in this case in human tissue. The problem is exemplified on a pacemaker electrode, but it can be applied in electrochemical cells like fuel cells, batteries, corrosion protection, or any other process where ionic conduction takes place in the absence of concentration ...

### Tubular Reactor with Nonisothermal Cooling Jacket

Chemical engineering students can model a nonideal tubular reactor, including radial and axial variations in temperature and composition, and investigate the impact of different operating conditions with this easy-to-use app. The process described by the Tubular Reactor with Nonisothermal Cooling Jacket app is the exothermic reaction of propylene oxide with water to form propylene glycol, ...

### Free Tetrahedral Meshing of a Piston Geometry

This is a tutorial model that demonstrates how to use mesh parameters such as Minimum element size Resolution of curvature Resolution of narrow regions Maximum element growth rate The instructions also detail how to access the mesh statistics and how to create a mesh plot.

### The KdV Equation and Solitons

The Korteweg-de Vries (KdV) equation models water waves. It contrasts sharply to the Burgers equation, because it introduces no dissipation and the waves travel seemingly forever. Solitons have their primary practical application in optical fibers. Specifically, a fiber’s linear dispersion properties level out a wave while the nonlinear properties give a focusing effect. The result is a very ...

### Transmission Line Parameter Calculator

Transmission line theory is a cornerstone in the teaching of RF and microwave engineering. Transmission lines are used to guide waves of electromagnetic fields at radio frequencies. They exist in a variety of forms, many of which are adapted for easy fabrication and employment in printed circuit board (PCB) designs. Often, they are used to carry information, with minimal loss and distortion, ...

### The Shallow Water Equations

The Shallow Water equations are frequently used for modeling both oceanographic and atmospheric fluid flow. Models of such systems lead to the prediction of areas eventually affected by pollution, coast erosion and polar ice-cap melting. Comprehensive modeling of such phenomena using physical descriptions such as the Navier-Stokes equations can often be problematic, due to the scale of the ...