LES Modeling of Premixed Deflagrating Flames in a Small-Scale Vented Explosion Chamber with a Series of Solid Obstructions

Abstract

In this study, simulations of propagating turbulent premixed deflagrating flames past built in solid obstructions in a laboratory scale explosion chamber has been carried out with the Large Eddy Simulation (LES) technique. The design of the chamber allows for up to three baffle plates to be positioned in the path of propagating flame, rendering different configurations, hence generating turbulence and modifying the structure of the reaction zone. Five important configurations are studied to understand the feedback mechanism between the flame-flow interactions and the burning rate. In LES, the sub-grid scale (SGS) reaction rate should be accounted for by an appropriate model that can essentially capture the physics. The present work has been carried by using the flame surface density (FSD) model for sub-grid scale reaction rate. The influence of the flow on turbulence and flame propagation as a result of the in-built solid obstructions is also examined. The impact of the number and the position of such baffle plates on the generated overpressure, flame speed and structure are studied. Results from the simulations are compared with experimental data for five configurations and they show good agreement.

Keywords:

• Deflagrating flames
• Explosion
• LES modeling