Numerical Simulation on Premixed Adiabatic Micro-Combustion of Hydrogen-Air Mixture

Understanding of micro-scale combustion mechanism is very essential to the development of combustionbased micro-power devices, which may supply much higher energy density than the batteries used nowadays. In the present study, a numerical simulation on hydrogen–air premixed combustion in adiabatic micro-combustors was investigated by solving the two dimensional governing equations. A series of combustor with various dimensions from 0.2 millimeter down to 0.05 millimeter but the same aspect ratio was studied and the effects of combustor size and slip-wall boundary condition on the flame temperature were investigated. The simulation results show that for combustion chamber with 0.05 millimeter diameter, Knudsen number is about 0.016, therefore the effects of slip-wall boundary is studied and temperature rise less than 10 Kelvin is observed. Moreover, it is shown that in a combustor with 0.1millimeter diameter, as the inlet velocity increases, output temperature increases as well.

Keywords:

Numerical simulation , Micro-combustion , Hydrogen-Air , Chemical reaction