On return stroke currents and remote electromagnetic fields associated with lightning strikes to tall structures: 1. Computational models
Notice bibliographique
Résumé
In this paper, analytical expressions relating far fields and currents associated with lightning strikes to tall towers are derived. The derived equations are general and can be used with any engineering model. It is shown that the far field can be decomposed into three terms, namely (1) contribution of the main return stroke pulse along the lightning channel, (2) contribution of the multiple‐reflection process along the elevated strike object, including the contribution of upward propagating pulses transmitted into the channel, and (3) contribution of the so‐called “turn‐on” terms, associated with the current discontinuity at the return stroke wavefront. This discontinuity is associated with neglecting reflections at the upward moving front. It is also shown that only the first term is model‐dependent and that the far field–current relationship does not significantly depend on the adopted engineering model. It is therefore possible to use the analytical equation relating the current peak and the associated distant electric or magnetic fields, derived by Bermudez et al. (2005) for the transmission line (TL) model, for any engineering model extended to include a tall strike object. It is also shown that the peak amplitude of the electromagnetic field radiated by a lightning strike to a tall structure is relatively insensitive both to the value of the return stroke speed and the top reflection coefficient. These results and findings of this paper emphasize the key differences between return strokes initiated at ground level (or from short strike objects) and those striking tall towers: (1) The electromagnetic field from lightning strikes to tall towers is largely determined by the tower and only to a lesser extent by the channel, (2) electromagnetic fields associated with tall strike objects are less model‐sensitive than those corresponding to a strike to ground; in particular, the early time response of the field is nearly model‐independent, and (3) unlike ground‐initiated strikes, for which the far field peak is strongly dependent on the return stroke speed (proportional according to the TL model), far field peaks associated with strikes to tall strike objects are little sensitive to the return stroke speed. This is a particularly interesting result when lightning currents are measured directly on instrumented towers to calibrate the performance of lightning location systems, since in most practical cases the value of the return stroke speed is unknown. Note that points (2) and (3) can be considered as corollaries of point (1).
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».