Comments on “Modeling of Magnetohydrodynamics in Nozzle Arc: A Mathematically and Numerically Efficient Approach”

In a recent article, Pawar and Sharma (2017) presented a mathematically and numerically efficient methodology based on solution to the magnetic induction equation which was referred to as the A4 approach for simulation of nozzle arcs. Despite the issue of current singularity, they demonstrated that the A4 approach is a fast and accurate strategy for predicting arc characteristics by also comparing with a singularity-free hybrid model also proposed by them. Revisiting the A4 approach, we show that a simple coordinate transformation can mitigate the axial current singularity and also describe a new hybrid approach that offers a consistent, cost-effective, and accurate alternative for magnetohydrodynamic (MHD) simulations of nozzle arcs.