Supporting Undergraduate Courses on Electromagnetism by Field Simulation Exercises IGTE, Graz, September 20th, 2010 Herbert De Gersem, Bart Vandewoestyne, Toon Roggen, Eef Temmerman, Bart Van Damme, Koen Vandenbussche, Hans Pottel The projects ''Physics experiments as starting point for interactive learning: from demonstration to exploration'' and ''Multidisciplinary learning environments for mechanics in biomedical, engineering and science education using biomechanical examples'' are financially supported by the OI- and OOF-funds for educational innovation of the K.U. Leuven and its association. The authors thank the CST AG for the classroom license of the CST Studio Suite.

Problem Statement course on electromagnetism: vectorial field lectures : show field plots (but passive) exercises : basically integrals, fields hidden (analytical field solutions → specialised courses) lab sessions : only global parameters (voltage, resistance) ? how to teach the electromagnetic-field concept ? simulation tasks visualisation possibilities cooking-book booby trap perception remains „virtual“, „artificial“

Integrated Laboratory Session simple and relevant example → single-phase transformer integrated exercise → analytical calculation, field simulation, measurements (exercises) (simulations) (lab experiments) requirements 1st year bachelor course heterogeneous student groups (eng,phys,math,chem) limited time (5 hours) minimise teaching load (increasing student population) challenges topic : electrical engineering is no part of the course simulation : 3D, nonlinear iron, eddy currents, forces, noise experiments : lab precautions

Preparation introductory text (to be read on beforehand) working principle (reminder) technical aspects (no part of the course!) analytical model (no part of the course!) AC circuit solving (preceeding exercises) http://www.kuleuven-kortrijk.be/~u0005424/labtrf_english.pdf

Approach + coil without core coil with core gradually built up δ no-load short-circuit + coil without core coil with core gradually built up coil with core and air gap transformer, no-load test transformer, short-circuit test

Approach + analytical experimental numerical δ no-load short-circuit + 3 tasks in parallel (student team) → all result tables have 3 columns student A student C student B analytical measured numerical k R1 Ω

Approach + analytical experimental numerical δ no-load short-circuit + compare and discuss results → get insight in modelling assumptions ← requires attention of teaching staff student A student C student B

Approach + analytical experimental numerical δ student A student C no-load short-circuit + student A student C student B detect (and cure) calculation and measurement errors yourself !

Tasks + analytical experimental numerical δ student A student C no-load short-circuit + student A student C student B

Tasks + analytical experimental numerical δ student A student C no-load short-circuit + student A student C student B

Tasks + analytical experimental numerical δ student A student C no-load short-circuit + student A student C student B define geometry & mesh

Tasks + analytical experimental numerical simulate magnetic field δ no-load short-circuit + student A student C student B are flux lines as expected ? link field plots to operation modes ! CST EM STUDIO (www.cst.com)

Tasks + analytical experimental numerical beyond analytical formulae δ no-load short-circuit + e.g. eddy currents → iron loss resistance student A student C student B

Results analytical measured numerical k 4.00 3.58 3.72 R1 Ω 11.2 11.6 5.0 4.8 RFe 750 910 Lh mH 35.7 32.2 33.3 Lσ1 1.3 2.4 1.7 Lσ2’ 2.1 results achieved at April 23th, 2009 by Ward Snoeck, Pieter Snauwaert and Hanne Deprez.

Conclusions for students process of simplification (reality → model) visualisation and interpretation of field plots (!) simulation and experiment next to each other comparison and discussion of results (differences!) analytical task boring, but necessary for checking for teaching staff teaching load: increased in 2008 & 2009, decreased since 2010 introductory text should be of high quality persuade the students to compare and discuss the results

http://www.kuleuven-kortrijk.be/~u0005424/labtrf_english.pdf