# Galeria de Modelos

A Galeria de Modelos possui arquivos do COMSOL Multiphysics de várias áreas de aplicação incluindo elétrica, mecânica, escoamento e química. Você pode baixar modelos prontos e também tutoriais passo-a-passo para montar seu modelo, e usá-lo como ponto de partida para o seu próprio modelo. Use a função de busca "Quick Search" para encontrar modelos na sua área de interesse e faça o login ou o seu cadastro no COMSOL Access, cadastrando a sua licença do COMSOL, para poder baixar os arquivos.

### Effective Diffusivity in Porous Materials - new

Transport through porous structures is usually treated using simplified homogeneous models with effective transport properties. This is in most cases a necessity, since the typical dimensions of the pores and particles making up the porous structure are several orders of magnitude smaller than the size of the domain that is to be modeled. This model introduces the concept of effective ...

### Implementing a Point Source using Poisson's Equation - new

This model solves the Poisson equation on a unit disk with a point source in the origin. The easiest way to describe a point source in COMSOL Multiphysics is by using an extra weak term. To obtain the weak formulation of the general Poisson equation, we multiply it with a test function u_test and integrate over the domain. The mesh density is dense, close to the origin, so as to resolve the ...

### Rock Fracture Flow - new

A potential flow model of fluid flow in a rock fracture uses the so-called Reynolds equation. It shows how to use experimental data interpolated to a function used in the equation.

### Acoustics of a Muffler - new

This is a model of the pressure wave propagation in a muffler for a combustion engine. The approach is general for analysis of damping of propagation of harmonic pressure waves. The model shows how 3D acoustics can be modeled in fairly complex geometries. It also shows COMSOL Multiphysics' coupling variable feature between different boundaries. The problem is solved in the frequency domain and ...

### Electric Sensor - new

This is a model from electric impedance tomography, a method of imaging the interior permittivity distribution of a body by measuring current and voltage at the surface. This model demonstrates how the shape and placement of figures with different material properties inside a closed box can be determined with this non-invasive technique. Applying a potential difference on the boundaries of ...

### Diffraction Patterns - new

This example resembles the well-known 2-slit interference experiment often demonstrated in schools with water waves or sound. This model mimics the plane-wave excitation with two thin waveguides leading to slits in a screen, and it computes the diffraction pattern on the screen’s other side. This diffraction pattern is clearly visible. The main effect of quantization is that the numerical ...

### Flow Between Parallel Plates

This example models the developing flow between two parallel plates. The purpose is to study the inlet effects in laminar flow at fairly moderate Reynolds numbers, in this case around 40. The problem might seem of academical nature but it is actually fairly common in catalytic reactors, heat exchangers, micro reactors etc. Symmetry along the thickness of the domain helps to reduce the ...

### Eigenmodes of a Room - new

When designing a concert hall it’s extremely important to take the resonances into account. For a clear and neutral sound, the eigenfrequencies should be evenly spread through the registers. For the home stereo owner, who can’t actually change the shape of his living room, another question is more relevant: where should the speakers be put for best sound? To illustrate the effects we are ...

### Joule Heating in a MEMS Device

This model exemplifies the use of the Material Library in the modeling of Joule heating in MEMS devices. The purpose of this analysis is to estimate the temperature of a conductor given an applied electrical potential difference. Both the thermal and electrical conductivities are temperature dependent. The influence of the temperature on the electrical conductivity results in a nonlinear ...

### Solution of the Schrödinger Equation for the Hydrogen Atom

This example shows how to compute energy levels and electron orbits for the hydrogen atom. It models the atom as a 1-particle system using the stationary Schrödinger equation. Before solving this problem in COMSOL Multiphysics, the dimension of the problem is firstly reduced from three to two by using cylindrical coordinates (rho, phi, z). The model is then set up using the PDE Coefficient ...