Characteristics of acoustic response from simulated impulsive lightning current discharge

Abstract

Acoustic observation of laboratory simulated lightning discharge can greatly avoid the observation difficulties under natural thunderstorm environment. An acoustic observation experiment based on the impulsive current generation system and a microphone array was carried out and illustrated in this study. A quantitative study on characteristics of response sound pressure initiated from simulated lightning current was performed. The first arrived acoustic N-waves measured at different distances initiated from different discharge amplitudes were compared and analysed. The acoustic amplitude, rise time and duration time defined for N-waves and peak frequencies were found to have an obvious correlation with the discharging amplitudes of simulated lightning currents and the observing distances. The linear change of acoustic amplitude is more obvious than that of the other parameters with the changed discharging amplitude or observing distance. A certain degree of shape change of the simulated lightning current except for the amplitude may not significantly affect the response acoustic characteristics when comparing the first acoustic N-waves from 8/20 μs lightning current and another kind of impulsive current which has a wider shape and two subsequent peaks. The subsequent current peaks in short time delays were proved to successively generate acoustic N-waves independently without overlapping, which meanwhile, indicated a consistent linear relationship of amplitude and time delay between electrical and acoustic pulses.

Developing Novel Gas Discharge Emitters of Acoustic Waves in Air for Nondestructive Testing of Materials

“…With a higher pulse power and longer inter-electrode gaps, the efficiency decreases. The same result was also obtained on a laboratory lightning simulator [ 17 ]. Some drawbacks of air-coupled devices were highlighted in [ 14 , 15 , 16 , 17 ], namely, the poor directivity of generated acoustic waves and the influence of environmental factors, such as air humidity and the ionization of gas in the inter-electrode space, on the magnitude of amplitude and phase jitter.…”

“…The resonance frequencies of the emitter depend on the size and properties of the membrane; however, the discharge itself appears broadband [ 14 , 15 , 16 , 17 ]. Therefore, the development of a membrane model simulating the vibrational characteristics of objects seems to be appropriate in order to minimize the size of experiments and correct some object properties, such as the mass/size ratio and rigidity and/or damping.…”

Differences between triggered lightning striking to ground and distribution line inferred from measured currents and electromagnetic fields

“…Current is a crucial lightning parameter and is important for lightning protection [5]. For instance, it can be used to estimate the charge carried by the leader [6].…”

Signal Processing of Acoustic Data for Condition Monitoring of an Aircraft Ignition System

“…A study by [28] investigated the directional characteristics of sparks, and found that the angular position of the microphone affects the widths and peak sound pressures of the received pulses. The authors in [29] observed the acoustic characteristics of lighting current discharge as a function of peak values of discharge currents. Spark characteristics have also been studied for enabling their utilization in studying acoustic phenomena on scale models [7].…”