The tilt angle and flame trajectory of jet diffusion flames under upslope and downslope wind conditions have not been studied before and no data are available in the literature. This paper presents an experimental investigation on the tilt angle and flame trajectory of a round jet diffusion flame under upslope and downslope wind with attack angles from 0° to ±20° and speeds from 0 to 2.45 m/s for downslope wind flow (-) and from 0 to 2.12 m/s for upslope wind flow (+). The tilt angle and flame trajectory are determined based on the luminous intermittency of the flame images. The results show that, at a given wind attack angle for upslope and downslope wind, the flame tilt angle generally increases with the increase of wind speed up to an asymptotic value. At a given wind speed, the flame tilt angle decreases with the increase of wind attack angles. It is also observed that the orientation of wind flow has different effects on the jet flame: for instance, as the wind attack angle increases, the phenomenon of flame downwash occurs at higher wind speeds than under horizontal flow. The flame trajectory in the jet region shows different evolutionary trends under upslope wind and downslope wind, which can be collapsed by normalizing coordinates with the length scale r2dj. Moreover, two correlations are developed to predict the tilt angle and flame trajectory of the curved jet diffusion flames under upslope and downslope winds, which are valuable for evaluating fire behavior under different wind conditions.

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>.