Ignition of current-taking Fluorinated ethylene propylene (FEP) insulated wire was investigated in a forced flow field in micro and normal gravities. A bursting jet was firstly observed after FEP insulation pyrolysis, and the induction time was observed before ignition occurred. Experimental and theoretical analysis show that: firstly, FEP insulation melts and decomposes, but with little liquid flow and low air permeability. The accumulated volatile gas inflates, causing jet bursting in both normal gravity and microgravity. Secondly, the forced flow and gravity has little effect on the core heating time and the bursting time, while the pyrolysis time increases slightly with increasing air velocity. Thirdly, the stretch rates in terms of the velocity gradients are higher in microgravity. In this work, the stretch rates are all positive indicating positively stretched flames. Both forced flow and gravity have significant effects on the induction time, which is dependent on the stretch rate and Damkohler numbers. Induction time increases with increasing air velocity, and is higher in microgravity. Finally, the ignition delay time is dominated by the core heating and bursting time, while its bigger value and faster increase in microgravity with increasing air velocity is dominated by the induction time.

International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]: 21-26 April 2019, Saint Petersburg, Russia. Vol. 1 / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 118 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-45.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-45>.