Missing BEM potentials about freefem-sources HOT 1 OPEN

Hello Caroline :-)

I think there is a slight confusion about the terminology:

• there are two potentials, the single and double layers potentials, convolutions with the green function and its normal derivative respectively
• there are four operators which are the Dirichlet and Neumann traces of the two potentials.

Note that potentials take traces and return functions in the volume, while operators take traces and return traces.

In particular, you can use the transpose double layer operator and the hypersingular operator as follows:

BemKernel TransposedDoubleLayerOperator("TDL",k=k);
BemKernel HyperSingularOperator("HS",k=k);

I guess the comment in the code you showed is a copy paste from the part defining the operators. You can checkout these examples for more details:

• https://github.com/FreeFem/FreeFem-sources/blob/master/examples/mpi/Helmholtz_circle_Dirichlet.edp
• https://github.com/FreeFem/FreeFem-sources/blob/master/examples/mpi/Helmholtz_circle_Neumann.edp

from freefem-sources.