# getDP model of a helicoidal symmetric power cable
This getDP model is an implementation answer of the question _"how to solve a helicoidal symmetric, time-harmonic eddy current boundary value problem (BVP)?"_ In a nutshell: Here, a special coordinate transformation is used to transform a 3D BVP into an equivalent 2D BVP, which is then solved by the finite element method (based on a $\mathbf{H}-\phi$ formulation using proper manipulated cohomology basis fuctions). This is demonstrated for a cable with 13 conductors, carrying each the same total current of $\sqrt{2}/13$ Amperes at frequency $50$ Hz. The resulting magnetic field $\mathbf{H}$ and current density $\mathbf{J}$ are plotted in the _physical_ coordinate system $(x,y,z)$ as well as in the helicoidal coordinate system $(u,v,w)$.
This getDP model is an implementation answer of the question _"how to solve a helicoidal symmetric, time-harmonic eddy current boundary value problem (BVP)?"_ In a nutshell: Here, a special coordinate transformation is used to transform a 3D BVP into an equivalent 2D BVP, which is then solved by the finite element method (based on a **H**-φ formulation using proper manipulated cohomology basis fuctions). This is demonstrated for a cable with 13 conductors, carrying each the same total current of √2/13 Amperes at frequency 50 Hz. The resulting magnetic field **H** and current density **J** are plotted in the _physical_ coordinate system (x,y,z) as well as in the helicoidal coordinate system (u,v,w).
The model had been developed by Julien Dular (University of Liege) and Albert Piwonski (Technische Universität Berlin).
Here you can find further information about the model and ansatz:
