Numerical Prediction of Levitation Properties of HTS Bulk in High Magnetic Fields

In this paper, high magnetic fields generated by HTS magnet, instead of permanent magnet, was adopted to enhance the levitation property of HTS bulk on the fact that levitation force is positively related to the magnetic field strength. Based on the generally-accepted H-formulation, a validated 2-D axisymmetric finite element model was established to study and predict the levitation performances of HTS bulk in high magnetic fields. The fishtail effect Jc(|B|,T) dependence, which is closer to reality demonstrating unique magnetic dependence of HTS critical current in high magnetic fields, was employed to improve the effectiveness of numerical model. The results indicate that the levitation force could be greatly improved by taking magnetic field close to the peak field of fishtail effect Jc(|B|,T) curve. This work could serve as a vital method to predict the levitation performance of HTS bulk in high magnetic fields and a guide concerning how to choose external field in balance of performance and cost in future applications.