Approximate numerical calculation method for deriving an asymmetrical temperature distribution in a cross‐section of a gas‐blasted arc

Abstract

A new ciilc.iiltition methotlfiir deriving un cisymmetrictil tempercitiire distrihiition in u cross-section of a n SF,-gri.s-blmteil (ire is proposed. Side-on profiles ogradiotion interisities ofJorir S+-ion spectrti observed from two clirectioiis perpenilicdar to euch other rire used us input tl~itci to determine usymmetrical distributions of emission coefficients in the crclss-section. The emission coefficient cli.stribiition ofeach spectrul line is iissumed t(1 be represoited by (I product ofthree expressions: one corre.sponding to CIII elliptic component, the others being two polyioinirils that give degree oj'osymmetq with respect to .r-und .v-rlirection. respectively Unknown coeflicients in two po1vnomial.s tire numericrillv determined b! rin iterrition process. From Bo1t:muiin plot diugrtim with respect to the emission coejjicients ojfi)iir S+-ion spectrril liriesfor each sputial pcisition. the usymmetrical terrrperatrire clistrihrition iJ'SF,-~~ti.s-blii.stetl tirc is estiiniitetl .siic~ces.vfiilly.

Position location of a filamentary arc using a tristimulus chromatic technique

“…Good agreement is found both for r and for θ. Similar agreements were obtained for the lamp filament placed at locations with θ = 0, π and 3 2 π radians, so confirming the validity of the approach. The absolute uncertainties in r and θ coordinates were determined to be ±1 mm and ±2.52 × 10 −2 radians, respectively, from results shown in figure 5.…”

“…The analysis hitherto has assumed a cylindrical symmetrical arc plasma column, although it is recognized that in practice this assumption is not always valid [2,3]. To examine the effect of departures from cylindrical symmetry, calculations have been done using a model, whereby the real arc cross section (major arc) is replaced by four adjacent symmetrical cross sections (minor arcs), one of them having an emission coefficient α times greater than those of the other three.…”

“…Experiments aimed at understanding various physical processes which govern electrical arc behaviour in various devices such as circuit breakers often assume the arc to be located on the central axis of the arc chamber, although there are optical observations indicating that this need not always be so [1][2][3]. In the case of circuit-breaker arcs sustained by a sinusoidal current, this off-axis arc location may cause residual high-temperature gas to exist off the central axis after the current-zero arc extinction and so can affect the current-interruption performance of the circuit breaker.…”

Total voltage drops in electrode fall regions of , argon and air arcs in current range from 10 to 20 000 A

“…The Boltzmann plot diagram [16,17] for the projective radiation intensities of four sulphur ion spectra at the radial distance of zero permitted approximate determination of the arc temperature T at a centre axis of the arc [18][19][20]. For the electrodes with a gap length L of 3 mm, T proved to range from 15 000 to 21 000 K at 1000 A and from 18 000 to 23 000 K at 5000 A.…”