Effect of surrounding air region size on finite element modeling for permanent magnetic solenoids

Magnetostatic finite element modeling of permanent magnetic devices can provide accurate results only if the underlying physics is well captured in the model. A single device surrounded by an air padding region is the focus of this research. In the ideal modeling case, this padding region would be infinite in extent. Since an infinite padding region is impossible to implement, the padding sizes in modeling a permanent magnetic solenoid that can ensure accurate results were analyzed in our study. The relationship between accuracy of the simulation result and the surrounding air padding percentage in terms of the device size is demonstrated in this paper, which shows that physically impossible results can occur for a permanent magnetic solenoid if an insufficient padding percentage is used. Design engineers typically use padding percentages from 40 – 400%, and our results show that the required padding percentage depends on the openness of the magnetic circuit. A permanent magnetic solenoid may have more or...