Calculation of air temperature and pressure history during the operation of a magnetic flux compression generator

Summary form only given. During the explosive operation of a MFCG, the air between the armature and stator is shocked and compressed. The resulting plasma could cause an electrical breakdown either between neighboring helix turns or between helix and armature, even before mechanical contacting occurs. When this happens, magnetic flux is lost and the electrical efficiency of the MFCG decreases. Therefore, the knowledge of gas temperature and pressure during the explosion phase of the MFCG´s operation is vital for the assessment of the severity of energy loss due to electrical breakdown in the MFCG gas-plasma. The area with the highest temperature and pressure is expected to be close to the armature-stator contact. This makes it difficult to measure the gas temperature and pressure in the MFCG. The objective of the work was to calculate the air temperature and pressure history by combining experimental and numerical simulation results. The methodology was to first calibrate the finite element simulation model by matching the deformed armature contour obtained from actual experiments with contours obtained from numerical simulations. Then, the air temperature in a template generator (6061-T6-aluminum armature/stator) was calculated using the pressure history data obtained from numerical simulations assuming adiabatic process conditions and utilizing an ideal gas equation of state.