Experiments on the effects of multiple obstacles in vented explosion chambers

Area of Science:

• Combustion science
• Fluid dynamics
• Mechanical engineering

Background:

• Flame propagation is a critical phenomenon in various industrial and safety applications.
• Understanding flame-obstacle interactions is essential for designing safer environments and predicting combustion behavior.

Purpose of the Study:

• To investigate the impact of multiple obstacles on flame propagation and pressure development in chambers of varying length-to-diameter (L/D) ratios.
• To analyze the influence of obstacle shape (square, triangular, circular) and blockage ratio on combustion dynamics.

Main Methods:

• Experimental setup using five rectangular chambers with heights ranging from 200 mm to 1000 mm.
• Introduction of three distinct obstacle types (square, triangular, circular) with blockage ratios of 30% and 43%.
• Measurement and analysis of flame speeds and pressure variations within the chambers.

Main Results:

• Flame speeds and pressures showed minimal variation for L/D ratios of 0.29 and 0.57.
• Chambers with L/D ratios above 0.86 exhibited sensitivity to obstacle type, L/D ratio, and blockage ratio.
• Triangular obstacles resulted in the highest overpressures, whereas cylindrical obstacles yielded the lowest.
• Flame and pressure development were found to be correlated in chambers with L/D ratios between 0.86 and 1.43.

Conclusions:

• Obstacle geometry and chamber L/D ratio significantly influence flame propagation and overpressure generation.
• The findings provide crucial data for mitigating explosion risks and optimizing combustion processes in confined spaces.
• Further research can explore a wider range of obstacle configurations and chamber geometries.