Title: Effects of obstacle BR on premixed hydrogen flame propagation behaviours in obstructed duct

Authors: Guanbing Cheng; Yaolin Li; Wentao Zhen; Fangyu Liu

Addresses: College of Aeronautical Engineering, Civil Aviation University of China, Tianjin, China ' College of Aeronautical Engineering, Civil Aviation University of China, Tianjin, China ' College of Aeronautical Engineering, Civil Aviation University of China, Tianjin, China ' College of Aeronautical Engineering, Civil Aviation University of China, Tianjin, China

Abstract: Because of energy shortage and fossil fuel pollution issues, hydrogen is considered as a promising alternative fuel. Effects of three Blockage Ratio (BR) obstacles were examined on premixed hydrogen flame propagation characteristics in duct. Physical and calculated models of a shock duct were established by ANSYS Fluent. Turbulent and combustion models were provided. Flame velocity, pressure and shape changes were examined. Hydrogen flame undergoes slow, fast deflagration, DDT and steady detonation process. High BR obstacle increases flame velocity and pressure, and also shortens flame characteristic parameters. The calculated detonation parameters agree with experimental ones. The sphere, finger and tooth flame are observed. Both flame surface area increase and interaction between flame and vortex accelerate the flame propagation in slow deflagration. Interaction between flame and shock wave is main physical mechanism in fast deflagration and deflagration detonation transition. The high BR obstacle raises oscillations of flame velocity and the wave pressure, but also produces more energy loss.

Keywords: hydrogen; shock duct; flame propagation; obstacle blockage ratio; velocity and pressure; numerical schlieren.

DOI: 10.1504/IJWMC.2025.147621

International Journal of Wireless and Mobile Computing, 2025 Vol.29 No.1, pp.93 - 101

Received: 06 May 2024
Accepted: 12 Aug 2024
Published online: 24 Jul 2025 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article