Computational Simulation of Sodium Doublet Line Intensities in Multibubble Sonoluminescence
Jin-Fu Liang1,4**, Yu An2, Wei-Zhong Chen3
1School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550025 2Department of Physics, Tsinghua University, Beijing 100084 3Institution of Acoustics, Nanjing University, Nanjing 210093 4Key Laboratory of Radio Astronomy of Guizhou Province, Guiyang 550025
Abstract:We perform a computational simulation of the fluid dynamics of sodium doublet (Na-D) line emissions from one sonoluminescing bubble among the cavitation bubbles in argon-saturated Na hydroxide (NaOH) aqueous solutions. Our simulation includes the distributions of acoustic pressures and the dynamics of cavitation bubbles by numerically solving the cavitation dynamic equation and bubble-pulsation equation. The simulation results demonstrate that when the maximum temperature inside a luminescing bubble is relatively low, two emission peaks from excited Na are prominent within the emission spectra, at wavelengths of 589.0 and 589.6 nm. As the maximum temperature of the bubble increases, the two peaks merge into one peak and the full width at half maximum of this peak increases. These calculations match with the observations of Na-D line emissions from MBSL occurring in aqueous solutions of NaOH under an argon gas.