Buoyancy Flow of Free Fluids
This model couples the Navier Stokes equations and the heat transfer equations to examine density driven flow of free fluids. Here the fluid is in a square cavity with a heated wall. The buoyancy force is a Boussinesq term added to the Navier-Stokes equations. The equation is nondimensionalized, so the material coefficients are set up using Rayleigh and Prandtl numbers. The parametric solver ...
Fluid-Structure Interaction in a Network of Blood Vessels
This model refers to a portion of the vascular system of a young child - the upper part of the aorta artery. The blood vessels are embedded in a biological tissue (the cardiac muscle) and, during the flow of blood, pressure is applied to the internal surfaces producing deformation of the vessel walls. The complete analysis consists of two distinct but coupled procedures: a fluid-dynamics ...
Effective Diffusivity in Porous Materials
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 ...
Loudspeaker Driver
This example shows you how to model a loudspeaker of the dynamic cone driver type, common for low and medium frequencies. The model analysis includes the total electric impedance and the on-axis sound pressure level at a nominal driving voltage, as functions of the frequency. The spatial characteristics of the speaker are depicted in a directivity plot. The tutorial model is set up using a ...
Simulating Wireless Power Transfer in Circular Loop Antennas
This model addresses the concept of wireless power transfer by studying the energy coupling between two circular loop antennas tuned for UHF RFID frequency whose size is reduced using chip inductors. The circular loop antenna provides inherent inductive coupling by its shape, and it can be easily miniaturized for low frequency applications. While the orientation of a transmitting antenna is ...
Free Convection in a Light Bulb
This model treats the free convection of argon gas within a light bulb. It shows the coupling of heat transport (conduction, radiation and convection) to momentum transport (non-isothermal flow) induced by density variations caused by temperature. COMSOL Multiphysics model makes it possible to determine the temperature distribution on the outer surface of the bulb, as well as the temperature ...
Cooling and Solidification of Metal
This example is a model of a continuous casting process. Liquid metal is poured into a mold of uniform cross section. The outside of the mold is cooled and the metal solidifies as it flows through. When the metal leaves the mold, it is completely solidified on the outside, but still liquid inside. The metal will continue to cool and eventually solidify completely, at which point it can be cut ...
Axisymmetric Transient Heat Transfer
This is a benchmark model for an axisymmetric transient thermal analysis. The temperature on the boundaries changes from 0 degrees C to 1000 degrees C at the start of the simulation. The temperature at 190 s from the anlysis is compared with a NAFEMS benchmark solution.
Bandgap Analysis of a Photonic Crystal
This model investigates the wave propagation in a photonic crystal that consists of GaAs pillars placed equidistant from each other. The distance between the pillars determines a relationship between the wave number and the frequency of the light, which prevents light of certain wavelengths propagating inside the crystal structure. This frequency range is called the photonic bandgap. There are ...
Forced Air Cooling with Heat Sink
Heat sinks are usually benchmarked with respect to their ability to dissipate heat for a given fan curve. One possible way to carry out this type of experiment is to place the heat sink in a rectangular channel with insulated walls. The temperature and pressure at the channel’s inlet and outlet, as well as the power required to keep the heat sink base at a given temperature, is then measured. ...
