Modeling of Bi-Polar Leader Inception and Propagation from Flying Aircraft Prior to a Lightning Strike

Abstract

Lightning is one of the major environmental threats to aircraft. The lightning strikes during flying are mostly attributed to aircraft-triggered lightning. The first step toward designing suitable protective measures against lightning is identifying the attachment locations. For this purpose, oversimplified approaches are currently employed, which do not represent the associated discharge phenomena. Therefore, in this work, a suitable model is developed for simulating the inception and propagation of bi-polar leader discharge from the aircraft. Modeling of leader discharges requires field computation around the aircraft, which is carried out employing the Surface Charge Simulation Method (SCSM) combined with sub-modeling, which ensures the best accuracy of field computations near nosecone, wingtips, etc. A DC10 aircraft model is considered for the simulation. Simulations are performed for different pairs of leader inception points on aircraft using the developed model. Subsequently, corresponding ambient fields required for stable bi-polar discharge from aircraft are determined. These values are in the range of measured ambient fields reported in the literature. In summary, the present work has come up with a suitable model for simulating the bi-polar leader inception and propagation from the flying aircraft. Using the same, a detailed quantitative description of the discharge phenomena from the aircraft is provided.

Possibility of Lightning Strike to Surface-Mounted Antennas on Aircraft

“…Hence, in the present work an attempt has been made to quantify this vulnerability using a model for airplane-initiated bipolar leader discharges. [8] investigation. The exterior skin of the airplane model is segregated into 11,000 surface elements which are triangular in shape through the use of Mesh Lab software.…”

“…Earlier investigations [8,11,12] have demonstrated that in the mode of lightning incepted by airplane, the potential initial attachment points are primarily limited to the extreme ends of the airplane, including the vertical fins, nose cone, wingtips, and similar areas. Apart from these, other extremities formed by the surface-mounted antennas are also present on the airplane.…”

“…Research in the field of bipolar discharge from floating objects within laboratory gaps is well-documented in the literature. In 1995, Rizk proposed an analytical model [4] to investigate the flashover of extended gaps in dedicated high voltage laboratories [5,8] involving a conductor which is electrically floating subjected to a switching surge. Subsequently, Castellani et al reported empirical data on discharges from an object which is electrically floating positioned in a plane-plane gap which is around 10-11m long [5,6].…”

“…Nevertheless, owing to the intricacies involved in the physics behind the inception and propagation of the discharge, there is a scarcity of literature on the simulation of such discharges from airplane. Das et.al has developed a model [8] which is capable of simulating bipolar leader discharges. The modeling of airplane-incepted leader discharges entails simulating both positive and negative leader discharges.…”

“…To achieve this, appropriate models for simulating these discharges from the airplane have been adopted from existing literature on laboratory experiments. For precise field computation, the Surface Charge Simulation Method (SCSM) has been utilized in [8], along with sub-modeling, which employs the Charge Simulation Method (CSM).…”