The discussion focuses on the assumptions and approximations made in 2D electrostatic modules within COMSOL, particularly regarding the treatment of the third dimension and the implications for solving the 2D Poisson's equation with point sources.
Participants express some agreement on the notion that 2D models represent a slice of a 3D geometry, but there is no consensus on the specifics of the assumptions regarding potential solutions or the implications of these approximations.
The discussion highlights the limitations of 2D modeling, particularly the assumption of uniformity along the z-axis and the mathematical treatment of boundaries in relation to the third dimension.
Is there anywhere I can find the documentation about this?DrClaude said:It is my understanding that the calculation represents a 2D slice of a uniform model in the z direction, as if it ws extending to infinity.
The following is a guide through some of the common approximations made for 2D problems. Remember that modeling in 2D usually represents some 3D geometry under the assumption that nothing changes in the third dimension.
Cartesian Coordinates
In this case you view a cross section in the xy-plane of the actual 3D geometry. The geometry is mathematically extended to infinity in both directions along the z-axis, assuming no variation along that axis. All the total flows in and out of boundaries are per unit length along the z-axis.