COMSOL 6.2 - Frequency-Transient

) study and study step are used to compute temperature changes over time together with the electromagnetic field distribution in the frequency domain.

The study is available, for example, with the following physics interface and module combinations:

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Induction Heating interface, which requires the AC/DC Module,

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Microwave Heating interface, which requires the RF Module,

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Acoustic Streaming with Pressure Acoustics, which requires the Acoustics Module,

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Acoustic Streaming with Thermoviscous Acoustics, which requires the Acoustics Module, or

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Laser Heating interface, which requires the Wave Optics Module.

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Inductively Coupled Plasma interface, which requires the AC/DC Module and the Plasma Module. For this physics interface, the temperature represents the electron temperature.

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Microwave Plasma interface, which requires the RF Module and the Plasma Module. For this physics interface, the temperature represents the electron temperature.

Physics interfaces that support the study and study step compute electromagnetic fields in the frequency domain and temperature (electron temperature for Inductively Coupled Plasma and Microwave Plasma) in the time domain. See Time Dependent for all settings. In addition to electromagnetic heating, the study can also be used to compute other physics field such as force in which time-averaged Lorentz force is computed.

For other interfaces that support the study, like Solid Mechanics, set the equation form to in the main node of the interface when they are solved in a study step.

Only use this study when the power transfer from the fields to any susceptible variables occurs at twice the angular frequency set by the study. In a large number of cases, the thermal time constant of an object of interest is substantially greater than the angular frequency of the electromagnetic radiation. In order to solve the problem in the time domain, tens or hundreds of thousands of RF cycles need to be computed by the solver before the problem evolves to the periodic steady-state solution. By solving for the fields in the frequency domain, the change in the fields over a single RF cycle does not need to be resolved, and the periodic steady state solution is reached much more rapidly. This means that the transient thermal response of an object is computed by this study, but any (small) fluctuations in temperature over any given RF cycle are not.

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With the AC/DC Module, see Inductive Heating of a Copper Cylinder, Application Library path .

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With the Plasma Module (plus AC/DC Module), see 3D ICP Reactor, Argon Chemistry, Application Library path .

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With the RF Module, see RF Heating, Application Library path .