Numerical simulation of detonation flame and combustion efficiency in pulse detonation combustor with different fuels

Abstract

The objectives of the present simulation to investigate the detonation flame propagation and pollutant emitted from pulse detonation combustor (PDC) at exhaust of detonation tube. The pilot gaseous hydrocarbon fuel such as n-pentane (C ₅ H ₁₂ ) and hexane (C ₆ H ₁₄ ) are injected to the cycle process of pulse detonation combustor with stoichiometric ( ϕ  = 1) fuel-air mixture. The k - ϵ turbulence model is used to simulate the unsteady reacting fuel-air mixture in fluent platform. The one step irreversible chemical kinetics model analyzed the details exothermic chemical reaction mechanism inside the combustor. The post processing result shows that at high flame temperature combustion wave propagates with supersonic flame propagation speed and increase the combustor pressure. From the simulation results it is found that the detonation wave speed reached to 2,220 m/s for n-pentane-air mixture combustion which is comparatively stronger than hexane-air mixture combustion. The minimum pollutant number of 0.00223 is obtained from n-pentane-air mixture, this magnitude is lesser compared to hexane-air combustion. Furthermore, the maximum combustion efficiency of 65 % is obtained from n-pentane-air mixture from detonation combustion process, which is comparatively higher than hexane-air mixture combustion.