Backcoupling of acoustic streaming on the temperature field inside high-intensity discharge lamps

TL;DR

This paper develops a 3D multiphysics model to analyze how acoustic streaming affects the temperature distribution inside high-intensity discharge lamps, predicting conditions leading to flicker and instability.

Contribution

It introduces a novel 3D multiphysics simulation approach to study the impact of acoustic streaming on lamp stability and temperature fields, linking acoustic resonances to flicker phenomena.

Findings

Model accurately predicts flicker onset

Acoustic streaming significantly influences temperature distribution

Experimental results validate the simulation predictions

Abstract

Operating high-intensity discharge lamps in the high frequency range (20-300 kHz) provides energy-saving and cost reduction potentials. However, commercially available lamp drivers do not make use of this operating strategy because light intensity fluctuations and even lamp destruction are possible. The reason for the fluctuating discharge arc are acoustic resonances in this frequency range that are excited in the arc tube. The acoustic resonances in turn generate a fluid flow that is caused by the acoustic streaming effect. Here, we present a 3D multiphysics model to determine the influence of acoustic streaming on the temperature field in the vicinity of an acoustic eigenfrequency. In that case a transition from stable to instable behavior occurs. The model is able to predict when light flicker can be expected. The results are in very good accordance with accompanying experiments.