Overview of the User’s Guide

The CFD Module User’s Guide gets you started with modeling CFD systems using COMSOL Multiphysics. The information in this guide is specific to this module. Instructions on how to use COMSOL in general are included with the COMSOL Multiphysics Reference Manual. For theory relating to the physics interfaces, see the end of each chapter.

	As detailed in the section Where Do I Access the Documentation and Application Libraries? this information can also be searched from the COMSOL Multiphysics software Help menu.

The Quick Start Guide includes some basic modeling strategies to get you started modeling fluid flow in your particular application area. For example, it gives some tips about how to control your material properties and how to set the optimal mesh to make solving the model easier and quicker. It also includes a summary of all the physics interfaces included with the CFD Module.

The CFD Module both extends physics interfaces available with COMSOL Multiphysics and provides additional physics interfaces. As a result, the module contains a wide range of physics interfaces for modeling various types of momentum transport. You can simulate laminar and turbulent flow, Newtonian and non-Newtonian flow, isothermal and nonisothermal flow, multiphase flow, and flow in porous media. The CFD Module also provides interfaces for modeling flows that occur in thin-films or in bounded regions, and in stationary and rotating domains.

On top of this, the CFD Module includes physics interfaces for modeling heat transfer, and transport and reactions of chemical species. These are typical phenomena that occur in fluid flow and are strongly coupled to the flow field.

The Single-Phase Flow Interfaces chapter describes the many physics interfaces available for laminar and turbulent flow. Modeling Single-Phase Flow helps you choose the best Fluid Flow interface for your particular application.

The CFD Module includes physics interfaces for the simulation of heat transfer in fluid flow. As with all other physics models simulated in COMSOL Multiphysics, any description involving heat transfer can be directly coupled to any other physical process. This is particularly relevant for systems with fluid flow and mass transfer. The interfaces also allow you to account for heat sources and sinks, such as energy evolving from chemical reactions.

The Heat Transfer and Nonisothermal Flow Interfaces chapter describes these physics interfaces in greater detail. To help you select which physics interface to use see Modeling Heat Transfer in the CFD Module.

The High Mach Number Flow Interfaces chapter describes three versions of the same predefined multiphysics interface used to model laminar and turbulent compressible flows at high Mach numbers.

The Multiphase Flow Interfaces chapter describes physics interfaces to model flows with more than one phase, for example flows with two fluids or flows with dispersed droplets or particles. To help you select which physics interface to use see Modeling Multiphase Flow.

The Porous Media and Subsurface Flow Interfaces chapter describes the , , and interfaces. To help you select which physics interface to use see Modeling Porous Media and Subsurface Flow.

The Chemical Species Transport Interfaces chapter describes physics interfaces that are used for the simulation of chemical reactions, and mass or material transport through diffusion and convection. Modeling Chemical Species Transport helps you select the best physics interface to use.

The Thin-Film Flow Interfaces chapter describes physics interfaces that model flow in thin regions such as lubrication shells and fluid bearings.

Mathematics, Moving Interface Branch describes the and interfaces found under the branch. In the CFD Module these physics features are integrated into the relevant physics interfaces.