Rotating Machinery, Nonisothermal Flow, Laminar Flow Interface
The Laminar Flow version of the Rotating Machinery, Nonisothermal Flow multiphysics interface (), found under the Fluid Flow > Nonisothermal Flow > Rotating Machinery, Nonisothermal Flow branch () when adding a physics interface, is used to simulate laminar flow and heat transfer in equipment containing one or more rotating parts.
This physics interface combines the capabilities of the Rotating Machinery, Laminar Flow interface and the Heat Transfer in Fluids interface, and can be used to simulate fluid flows where the fluid properties depend on the temperature. Furthermore it is also possible to include heat transfer in solids, stationary and rotating, as well as surface-to-surface radiation and radiation in participating media. The physics interface is available in 2D and 3D and supports low Mach number (typically less than 0.3) flows, as well as non-Newtonian fluids.
Four study types are available for this physics interface. Using the Time Dependent study type, the rotation is achieved through moving mesh functionality, also known as sliding mesh. Using the Frozen Rotor study, the rotating parts are kept frozen in position, and the rotation is accounted for by the inclusion of centrifugal and Coriolis forces. The Time Dependent, One-Way NITF and Frozen Rotor, One-Way NITF study are used for frozen rotor and time dependent nonisothermal flow computations where the temperature variations are so small that they do not affect the flow.
When adding the multiphysics interface, the Laminar Flow and Heat Transfer in Fluids interfaces are added to the Model Builder. A Moving Mesh interface with a Rotating Domain node is added automatically in the Model Builder under the Definitions node. In addition, the Multiphysics node is added, which automatically includes the multiphysics coupling feature Nonisothermal Flow. The following default nodes are also added in the Model Builder under Laminar Flow — Fluid Properties, Wall, and Initial Values; and under Heat Transfer in Fluids — Fluid, Thermal Insulation, and Initial Values.
In earlier versions of COMSOL Multiphysics (prior to version 5.4), a specific physics interface called Rotating Machinery, Nonisothermal Flow (rmnitf) was added to the Model Builder. Now, a predefined multiphysics coupling approach is used, improving the flexibility and design options for your modeling. For specific details, see The Multiphysics Branch and Multiphysics Modeling Workflow in the COMSOL Multiphysics Reference Manual.
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Domain, Boundary, Edge, Point, and Pair Nodes for the Rotating Machinery, Nonisothermal Flow Interfaces
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Theory for the Free Surface Features in the Mixer Module User’s Guide
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Modeling Heat Transfer in the CFD Module
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The Nonisothermal Flow and Conjugate Heat Transfer, Laminar Flow, Turbulent Flow and LES Interfaces
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Theory for the Nonisothermal Flow and Conjugate Heat Transfer Interfaces
The Time Dependent, One-Way NITF and Frozen Rotor, One-Way NITF studies are used for frozen rotor and time dependent nonisothermal flow computations where the temperature variations are so small that they do not affect the flow.