| Autor: |
Salze, Édouard, Vagnon, Éric, Ollivier, Sébastien, El-Khattabi, Mohamed, Zouaghi, Ayyoub, Dragna, Didier, Blanc-Benon, Philippe |
| Předmět: |
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| Zdroj: |
Proceedings of Meetings on Acoustics; 7/4/2022, Vol. 48 Issue 1, p1-11, 11p |
| Abstrakt: |
Thunder initiated from lightnings can be heard up to tens of kilometers, with an acoustic pressure up to several pascals. In real atmospheric conditions, the generation of acoustic waves is conditioned by the electric energy, which is not measurable. The geometry of the strikes, for example their length and curvature, also has a great influence on the acoustic waveforms. Furthermore, the real atmospheric conditions (temperature, wind direction or intensity), cannot be controlled nor measured extensively. In this communication, a laboratory-scale acoustical characterisation of thunder is performed on a 75 centimeters long lightning strike. Every strike is characterised using a microphone array, and a synchronised optical visualisation to obtain the shape of the discharge channel. A synchronised measurement of electrical parameters (discharge current and instantaneous voltage) is also performed to obtain the energy of the discharge. The waveforms are similar to those measured on smaller sparks, with an N-wave structure. However the electric parameters are well controlled and stable, a large waveform variability is observed 6 meters away from the source, with acoustic peak pressure between 200 and 600 pascals, and arrival times between 16.5 and 17 microseconds. This variability is linked to the observed variability of the discharge channel geometry. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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