Prediction model for self-similar propagation and blast wave generation of premixed flames. (14th September 2015)

• Record Type: Journal Article
• Authors: Kim, Woo Kyung; Mogi, Toshio; Kuwana, Kazunori; Dobashi, Ritsu
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 34(2015)
• Page Start: 11087
• Page End: 11092
• Publication Date: 2015-09-14
• Subjects: Flame acceleration -- Self-similar propagation -- Expanding spherical flame -- Blast wave -- Explosion; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.06.123
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: This paper presents a simple model to predict the flame speed and the blast pressure during an unconfined gas explosion. The proposed model is a modification to the fractal-based model proposed by Gostintsev et al. In the original model, the flame radius, r, is expressed as a function of time, t, as r / ( κ / ε S L ) = c g [ t / ( κ / ε 2 S L 2 ) ] α, where κ is the thermal diffusivity, ε is the volumetric expansion ratio, S L is the laminar burning velocity, c g is the model constant, and α is the acceleration exponent. The present model expresses model constant c g using the properties of gas mixture. In this study, field experiments of gas explosion are conducted for hydrogen/air, methane/air, and propane/air mixtures confined in a 1- or 27-m 3 regular cubic plastic tent. The experimental results demonstrate the nature of self-similarity in the explosions and the experimental acceleration exponent associated with a fractal dimension is evaluated. The model is developed by using the concept of self-similarity and an acoustic theory. The predicted flame speed and the blast pressure are compared with experimental data of larger-scale hydrogen/air, methane/air and propane/air explosions under a wide range of conditions. The model predictions agree reasonably well with the experimental data, validating the proposed model. Highlights: A simple model to predict the flame speed and the blast pressure during an unconfined gas explosion is developed. The model is developed by using the concept of self-similarity and an acoustic theory. The predicted flame speed and the blast pressure are compared with experimental under a wide range of conditions. The model predictions agree reasonably well with the experimental data.