This model considers a square inductor that is used for LC bandpass filters in MEMS systems. The simulation calculates the self-inductance. The first step in the modeling is to compute the currents in the inductor. These currents are the source for the magnetic flux computations, carried out in a second step.
This model solves the Testing Electromagnetic Analysis Methods (TEAM) problem 7, “Asymmetrical Conductor with a Hole”—a benchmark problem concerning the calculation of eddy currents and magnetic fields produced when an aluminum conductor is placed asymmetrically above a multi-turn coil carrying a sinusoidally varying current. The simulation results at specified positions in space are ...
This model shows how to combine an electric circuit simulation with a finite element simulation. The finite element model is an inductor with a nonlinear magnetic core and 1000 turns, where the number of turns is modeled using a distributed current technique. The circuit is imported into COMSOL Multiphysics as a SPICE netlist, which merges the inductor model and the circuit elements as ODEs.
This is a tutorial how to set up electric machinery in 3D using a combination of the magnetic fields and magnetic fields no currents interfaces.
A transient model of a capacitor is solved in combination with an external electrical circuit. The finite element model of the capacitor is combined with a circuit model of a voltage source and a resistor. A step change in voltage is applied, and the transient current through the capacitor is computed and compared to the analytic result.
Particle Tracing is used in conjunction with magnetic fields and pressure-driven microfluidic flow to calculate the separation of red blood cells from blood plasma using magnetophoresis. An array of soft iron rectangles on either side of a microfluidics channel modifies the magnetic field induced by a pair of neodymium permanent magnets. The resulting strong gradients in the magnetic field ...
A capacitor with an applied sinusoidally time-varying voltage difference is modeled. A wide frequency range is considered and the impedance of the device is computed. Solver accuracy is addressed. The relationship between the frequency domain impedance and the steady-state capacitance and resistance of the device is discussed.
Magnetostrictive material exhibits free strain under the influence of magnetic field. It also exhibits a stress-induced change in magnetization in the presence of a bias magnetic field. In this tutorial we model a quasi-static transducer which has a steel housing enclosing a drive coil. A magnetostrictive material is placed in the core. Magnetic and structural interactions between the ...
An AC coil surrounding a metal cylinder induces eddy currents in the cylinder. The driving current in the coil can be specified in two ways: either as an external current density or as equivalent surface currents. In the first case, the skin effect can be studied by giving the coil a non-zero conductivity.
The induced currents in a copper cylinder produce heat that in turn change the electrical conductivity. This means that the field propagation has to be solved simultaneously with the heat transfer through the cylinder and surrounding system. This model shows this coupling between eddy currents and heat transfer as a tutorial example.