An error indicator for the calculation of global quantities by the p-adaptive finite element method

While general error indicators based on assessment of the quality of the field have been successfully used in adaptive finite element methods, here an error indicator that chooses elements based on their contribution to a specified global quantity is presented. This Targeted Error Indicator (TEI) can be applied to single or multiple solution problems. The inductance of a coil wrapped around a C shaped core and the input impedance to two coupled coils serve as examples of global quantities for single and multiple solution cases. When compared to a general error indicator, the TEI leads to more accurate and more rapidly converging global values.