Numerical study of the effect of carbon oxide addition on dimethyl ether-air flames

Numerical simulation has shown that the effect of CO addition in small quantities to rich dimethyl ether mixtures is due only to the physical contribution to the normal flame speed. There is no chemical contribution. Therefore, extrapolation of linear regions of the dependences of rich flammability limits to zero concentrations of nitrogen, CO$_2$, and CO gives the same value of the dimethyl ether concentration. The relationship between the chemical and physical contributions of the effect of a fixed CO additive was obtained over the entire range of dimethyl ether concentration in the mixture with air. The addition of CO affects the occurrence of superadiabatic temperatures in the dimethyl ether flame in the same ways as the addition of inert CO$_2$ and N$_2$.