Acceleration of Flames in Tube Explosions with Two Obstacles as a Function of the Obstacle Separation Distance: The Influence of Mixture Reactivity

Explosion flame acceleration over obstacles: Effects of separation distance for a range of scales

“…8 lie close to the line with C = 4 in Eq. 6 [33], but the previous results of Na'inna et al with two interacting grid plates with 30% BR [17,18] were closer to C = 2 at the higher u'/SL of this work. ST/SL ratios of 55 to 120 were found for two interacting bar type grid plates with a BR of 20%.…”

“…Also included in Fig. 8 are the previous results of Na'inna et al [17,18] for orifice plate circular hole grid plates of 30% BR with varying separation distance and for different mixture reactivities. Figure 8 also includes the data range from the review of turbulent to laminar burning velocity ratio of Phylaktou et al [32,33], which extends to ST/SL of 120.…”

“…Na'inna et al [18] have also examined the effect of mixture reactivity on the optimum obstacle In furtherance to the study of effects of obstacle separation distance on gas explosions, Na'inna et al The present work studied the interaction of two obstacles having a BR of 20% with the aim of focusing on the effect of the obstacle characteristic scale. To this purpose, flat bar obstacles were used as these had a more easily defined and uniform length scale, compared to circular hole grid plates.…”

The effect of vent size and congestion in large-scale vented natural gas/air explosions

“…Previous studies have shown that reducing the vent size and increasing congestion, in the form of obstacles in the path of the propagating flame front, can affect flame speeds and result in increased overpressures in vented explosions Bauwens et al, 2010;Bimson et al, 1993;Chan et al, 1983;Fakandu et al, 2013;Hall, Masri, Yaroshchyk, & Ibrahim, 2009;Mercx et al, 1993;Na'inna, Phylaktou, & Andrews, 2013a, 2013bPappas, 1983;Park, Lee, & Green, 2008;Phylaktou & Andrews, 1994;Phylaktou, 1993;Pritchard, Hedley, & Webber, 2002;Solberg, Pappas, & Skramstad, 1980;Taylor & Bimson, 1989;van Wingerden, 1984avan Wingerden, , 1984cvan Wingerden, 1989;van Wingerden & Zeeuwen, 1983a, 1983cZalosh, 1980Zalosh, , 2008.…”