A Polar Coordinate Integration Scheme with a Hierarchical Correction Procedure to Improve Numerical Accuracy

Numerical accuracy in the boundary element method (BEM) depends on the errors appearing from approximation of geometry, interpolation of functions and the integration scheme. Among them, the integration scheme represents a large share and it may significantly deteriorate the numerical accuracy in an ordinary boundary element formulation because integration includes a singular kernel. It is known that direct application of numerical quadratures fails to predict the value of an unknown function near the integration points.