Field Problems in Magnetic Devices

Abstract

Field problems as handled by the analyst are mathematical or computational abstractions of reality. The real physical world’s rich complexity of detail precludes taking account of any but a few selected features of a device in the process of analysis, so it becomes the responsibility of the design engineer to decide what aspects to include, which to ignore, and which to represent in an approximate fashion. Although there are many good computer programs to perform every mathematical step of the analysis itself, no computer can undertake to select which features of a device are important, and which results are desirable. The art of magnetic design in the brave new world of CAD bears some resemblance to the craft of the graphic artist in a world endowed with photography. Compared to an earlier age, there is less need for detailed mastery of the trade secrets and craft tricks of algebraic manipulation and calculation—the machines can handle much of that—and an ever increasing need for sensitive perception in selection, abstraction, and interpretation. Accordingly, the formulation of problems, rather than their solution, comes to occupy a primary role, as this chapter seeks to illustrate.