Insert Gas Dilution and Temperature Effects on Laminar Burning Velocity of DME plus Air Mixtures

The influence of blending the mixture of dimethyl ether and air using inert gases and initial temperature on laminar burning velocity (LBV) was investigated experimentally at ambient pressure. In the present work, premixed planar (flat/ 1D) flames of laminar nature at various temperatures were achieved using an increasing aspect-ratio channel by placing an electric heater externally beneath the channel made of quartz material. These tests were performed for a wide range of mixture compositions with equivalence ratio varying (0.8 <= Phi <= 1.3) and temperature ranging from 330 to 570 K. Comparison between the obtained burning velocities with the numerical prediction and detailed flame structure using the Zhao mechanism for dimethyl ether + air mixtures was also made, which was validated against the experiments very well. The results show the burning velocity to decrease monotonously with the increase in percentage dilution for both inert gas dilutions, while the peak burning velocity obtained is for a somewhat rich mixture for all dilution cases. In addition to this, the trend of power-law temperature exponent alpha (from curve fitting) with the diluted mixture equivalence ratio (Phi) is also reported. The addition of CO2 has more deterring influence mutually on LBV as well as on a compared with N-2 addition.