Mohamed Bechir Ben Hamida

Three dimensional numerical study of different parameters effect on the external magnetic field applied to center the arc of the horizontal mercury discharge lamp

The aim of this paper is to evaluate the magnitude of the external magnetic field to be applied to a horizontal mercury discharge lamp such that the Lorentz forces counterbalance buoyancy forces and the hot region of the arc remains centered inside the lamp with the variation of six parameters of the lamp such as the external temperature of the lamp, envelope thickness, convective loss, Interelectrodeslength, pressure and current supply pointing to the influence of the parameters to the compensating magnetic field value. To achieve this objective, a commercial numerical software “Comsol Multiphysics” is used to implement the model that solves the equations of mass, energy and momentum for laminar compressible flow combined with the Laplace equation for the plasma in a three dimensional.

Contrasting the Effect of Electric Current Between Vertical and Horizontal High-Pressure Mercury Discharge Lamps

This paper discusses the thermal behavior of a high-pressure mercury lamp in a horizontal position compared to that of a vertical lamp when the supply current varies. The model adopted is 3-D, steady, and dc powered. After the validation of the model, pressure of the lamp is kept at 6 × 105 Pa and the supply current varied from 1 to 10 A. Then, by comparing the case of the lamp in a horizontal position with that in a vertical one, the temperature fields, the flow of heat conduction, the flow of convective heat, and the accumulation of mercury behind the electrodes are analyzed.