HMagn5: Induction pump

In induction pump the travelling electromagnetic field induces eddy currents in the liquid metal, and interaction between the field and currents generate the force which moves the metal. The eddy currents value depends on the metal conductivity, which depends on temperature. Calculate the pump force and pressure as functions of temperature.

Problem Type:
An axisymmetric problem of nonlinear AC magnetics.

Geometry:
Due to the axial symmetry only the upper half is presented in the model.
Inductive pump In inductive pump the alternating magnetic field induces eddy currents in the liquid metal, and interaction between the magnetic field and the currents generate the force which moves the metal through the pipe. 212 mm Ø60 mm Non-magnetic pipe Ferromagnetic core A+ C- B+ A- C+ B-

Given:
Magnetic permeability of the steel core μ = 200;
Conductivity of the liquid metal σ - depends on temperature, as shown on the plot below;
Winding current density j = 6 A/mm2;
Frequency f = 50 Hz.

Problem:
Calculate the pump force and pressure as functions of temperature.

Solution:
As the induced current rapidly fades outside the inductor it is possible to limit the model z-length by 400 mm.
Conductivity vs. temperature dependency was specified for the 'liquid metal' block.
The series of problems was solved for temperature range 600-900°C. The mechanical force acting on the liquid metal was calculated at each step.

Results:

Temperature, °C Force, H Pressure, Pa
100 41 14 500
200 30 10 500
600 23 8 100
900 18 6 500

See the HMagn5.pbm problem in the Examples folder.