Effect of Obstruction Aspect Ratio in a Suddenly Expanded Micro-combustor

In the present paper, the energy conversion efficiency of premixed H2–air combustion in the form of outer wall temperature is explored for a 2-D axi-symmetric micro-combustor having a backward-facing step and a triangular obstruction. Numerical investigations are conducted by varying inlet velocity (4–48 m/s) and obstruction length-to-height ratio (defined as aspect ratio AR = d/b ratio = 1, 2 and 3). The outer wall temperature was found to be significantly influenced by inlet velocity and the presence of obstruction but the aspect ratio only slightly effected the temperature distribution of outer wall.