Details

Numerical simulations were conducted to understand the effect of obstacle shape on flame acceleration and deflagration-to-detonation transition (DDT) through an array of obstacles in a channel. The multidimensional, fully compressible reactive Navier-Stokes equations, coupled to a calibrated chemicaldiffusive model for combustion of a stoichiometric hydrogen-air mixture, were solved using a high-order algorithm with adaptive mesh refinement (AMR). While maintaining the same blockage ratio, the influence of obstacle shape on DDT was examined with circular, square, and triangular obstacles. The simulations show that the shape of the obstacle plays an important role in flame acceleration and detonation initiation. Squares create spaces between obstacles and walls, and these spaces provide a path that leads to the fastest flame acceleration and shortest detonation initiation time compared to circular and triangle obstacles. The presence of sharp angles on the triangular obstacles is favorable for flame stretching and convolution, and this facilitates flame acceleration and transition to detonation. The round, circular obstacles have the least effect on promoting flame acceleration and DDT. Although there are differences in flame acceleration and DDT among differently shaped obstacles, the basic mechanism for detonation initiation is similar in all of the cases studied and involves shock interactions with flame front.

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>.