The default Name (for the first physics interface in the model) is cdbem.

When the Infinite void is selected the boundary element formulation includes infinity. Use the settings of the Infinity Condition section to set the boundary condition for the potential at infinity.

Note: The default domain selection of the interface is All domains and voids which includes the Infinite void. The domain number of the infinite void is 0. Another way to add the Infinite void to the selection is to click Paste Selection and type in 0.

Use the applicable combo boxes to activate a symmetry plane in 3D space dimension and a symmetry line in 2D space dimension and specify the location (x, y, z) of the plane/line using the Plane position/Line position parameter.

The BEM problem is solved with Use far field approximation checkbox enabled and using an iterative solver by default. The far field approximation in combination with an iterative solver may in many cases lead to a significantly lower computational load.

The settings are only active if the Infinite Void is included in the selection.

To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog.

Select the Thin gap handling checkbox to increase the accuracy of the quadrature between almost-touching mesh element pairs (that is, pairs that are extremely close with respect to element size). The value in the Threshold distance (relative to mesh size) controls the distance at which elements are considered as almost touching (default value: 0.1). A larger value should provide more accurate results but at an increased computational cost. Under Integration order, the Integration order, very close elements (thin gap) option becomes active, making it possible to set a higher-order rule for such elements. In 3D, an additional variable transformation is applied to improve the accuracy even further.

The settings under Integration order are by default set to Automatic. This means that the quadrature integration order values will follow the element order selection in the Discretization section. Higher element orders automatically generate higher values for the quadrature integration orders.

The quadrature integration order settings determine the level of accuracy of the computation of double integrals over the singular integral kernels that need to be evaluated for solving the BEM integral equations. For contributions from overlapping mesh element pairs (identical elements, elements sharing common edge, or elements with common vertex), specialized regularization transformations are applied before proceeding with numerical integration. For evaluation of contributions from nonoverlapping mesh element pairs, standard numerical integration is used. Due to the presence of singularities in the double integrals, higher integration order is needed for close mesh element pairs than for distant mesh element pairs. The following integration order settings are available when you select Manual:

The selection from the Current Distribution Type list governs how electrode reactions are modeled on interfaces between electrodes and electrolytes.

The Physics vs. Materials Reference Electrode Potential setting on the physics interface node can be used to combine material library data for current densities and equilibrium potentials with an arbitrary reference electrode scale in the physics. The setting affects the electrode potentials used for model input into the materials node, as well as all equilibrium potential values output from the materials node.

Note that the setting will only impact how potentials are interpreted in communication between the physics and the Materials node. If the From Materials option is not in use for equilibrium potentials or electrode kinetics, the setting has no impact.