TEAM Benchmark 7 - Asymmetrical conductor model with a hole

The TEAM Benchmarks originate from the Argonne National Laboratory (ANL) in 1985 where a series of workshops started in 1986. In short, the goal of the workshops and ensuing benchmarks was [1] to "show the effectiveness of numerical techniques and associated computer codes in solving electromagnetic field problems, and to gain confidence in their predictions. The workshops should also provide cooperation between workers, leading to an interchange of ideas."

The TEAM 7 benchmark was solved using the low frequency eddy current solver in CST EMS. The model shown in Figure 1 was constructed within a few minutes using the powerful solid modelling tools in CST EMS. A block was created from which another rectangular block was subtracted. The coil was created by defining rectangular curve of the cross section and defining a sweep curve for the rectangular shape. Rounding of the rectangular sweep block was facilitated by the blending function in CST EMS.

The conducting plate has a conductivity of 3.526e7 S/m with dimensions 294mm by 294mm by 19mm. The hole is 108mm by 108mm. The coil is placed 30mm above the plate and excited with 2472 Ampere-Turns at 50Hz. The driving current reaches the maximum at a phase of 0 degrees. The normal component of the B field to the plate is recorded on a measurement-line defined by a curve item between the plate and the coil.

Figure 2 shows the tetrahedral mesh in the plate and coils and consists of approx. 327,000 tetrahedrons.

The simulation, involving more than 381,000 unknowns, was simulated to an accuracy of 1e-6 in just over 2 minutes on a Xeon 2.8Ghz, 2GB machine. This demonstrates the excellent performance state-of-the-art solver technology in the low frequency module. Figures 3 and 4 show the vector plots of the eddy current distribution at phases wt=0 and wt=90 respectively.

The graph in Figure 5 shows the normal component of magnetic flux density, B along the predefined curve.

CST EMS can be effectivley applied to simulation of eddy current problems. This TEAM benchmark was constructed rapidly using the powerful modelling tools in CST EMS and solved efficiently using the latest in solver algorithms. The excellent solver performance enables fast parameter studies of models or the simulation of models containing a large number of unkowns.

[1] Larry R. Turner,  "The TEAM Workshops: A Short History" LS Note 153, Argonne National Laboratory, http://www.aps.anl.gov/Facility/Technical_Publications/lsnotes/ls153/ls153.html