Integral methods of analysing electric arcs. III. Shape-factor correlation for low radiation and laminar flow

Abstract

For pt.II see ibid., vol.7, p.2232 (1974). The energy equation for the core of axisymmetric electric arcs is de- rived in terms of radial integrals. The formulation includes terms to describe the diffusive heat flux at the core boundary and the work done against viscous stress there. When the shape factors derived in Part I are evaluated for a number of different arc situations from known differential solutions, they correlate well in terms of a non-dimensional form of the heat flux. This result suggests that arc behaviour can be predicted accurately by the overall integral equations of Part I and the core energy equation, together with empirical curves relating shape factors to non-dimensional heat flux, provided that the flow is laminar and there is negligible radiation.