Engineering topics

Boulay, J. L.

Publications and source records attributed to Boulay, J. L..

3 records

NASA NTRS1991

Current wave-form observed during lightning strikes on aircraft

A preliminary validation of a number of mechanisms that can be associated with the various phases encountered during in-flight lightning strikes are provided. It is known that a lightning strike on an aircraft occurs in several phases: a preparation phase, an electric arc attachment phase, a connection phase, and a re-light phase. This analysis is confined to the study of the readings obtained during the electric arc attachment phase and to experiments carried out to validate the scenarios that are currently understood. The objective of the analysis is to explain this attachment phase. A brief review of the experiments that are currently being performed in an attempt to understand the re-light phase is also presented.

Boulay, J. L.↗

NASA NTRS1991

Application of surface electrical discharges to the study of lightning strikes on aircraft

Considered here is the characterization of surface discharges which provide a facility complementary to that of artificially triggered lightning. General characteristics of a simplified surface discharge, including current waveforms and the constitution of a surface discharge are outlined, and the application of this approach to the study of aircraft lightning strikes is considered. Representations of leader-streamer and return-stroke phases are discussed, and the application to the two-dimensional discharge phase is covered. It is noted that the fact that the initiation times of surface discharges could be controlled, and the path followed by the discharge channels could be predetermined, indicates that it is possible to produce a highly dedicated high performance instrumentation system.

Boulay, J. L.↗

NASA NTRS1991

LIDAR studies on microbursts

Preliminary analysis of requirements for future airborne windshear detection systems is presented. The following topics are covered: flight mechanics; microbursts modeling; microburst detection with airborne systems (LIDAR, radar, passive IR sensors); microbursts prediction with ground systems (VHF interferometry). A short overview of these studies is presented and some results are discussed.

Aurenche, Y.↗