Three-dimensional modeling of a direct current operated Hg-Ar lamp

Understanding and modelling plasma–electrode interaction in high-pressure arc discharges: a review

“…Values of the maximum gas velocity in HID lamps calculated by most authors are of the order 0.1-0.2 m s −1 (e.g. [9][10][11][12][13][14]), although substantially higher calculated values of 6-8 m s −1 have also been reported [15,16]. Since the gas velocity in the immediate vicinity of the electrode is smaller than the maximum gas velocity in the lamp, one can set v = 0.1 m s −1 .…”

“…Then the nearcathode voltage drop U should be treated as a function of time to be determined. In other words, problem (13), (14) should be solved jointly with equation (15) for the functions T (r, t) and U(t) (here r denotes the space vector). The situation becomes simpler in the particular case of steadystate current transfer: problem (13), (14) can be solved for a given value of U independently of equation (15), after which a value of I corresponding to this U may be found by means of equation (15); repeating this step with various U, one can obtain a complete description of the current-voltage characteristic (CVC) of the desired mode of current transfer.…”

Contrast the Effect of the Mass of Mercury Between the Vertical and Horizontal Mercury Discharge Lamps

“…In addition, these lamps are characterized by high luminous efficiency and a very good color rendering index and are used today in a wide variety.Most studies have been devoted to the study of lamps placed in vertical positions [3]- [9]. For example, Charrada et al [10]- [12] and Beks et al [13] have studied the phenomenon of convection in a vertical high-pressure mercury lamp, supplied with a dc.…”

“…Currently, very few 3-D models have been developed for these systems [3], [15], [16]. Therefore, we thought that it is appropriate to develop a 3-D numerical code based on solving equations "fluid" governing the plasma in the local thermodynamic equilibrium (LTE) state.…”

Contrast between the vertical and horizontal mercury discharge lamps

“…1,2 We can find, in the literature, several modeling works for high-pressure discharge lamps and particularly the high-pressure mercury lamp. [3][4][5][6][7] Charrada et al [8][9][10] have studied the phenomenon of convection in a vertical high-pressure mercury lamp, supplied with a direct current. Similar investigations were carried out by Beks.…”