“…On the other hand, a higher ozone concentration of up to 7000 ppm is typically used in the fundamental research of laminar flames [28][29][30][31]. For example, when ozone is added to the fuel mixture, improvements in the ignition of methane (CH4) [32][33][34] as well as the flammability limits for methane and propane (C3H8) [35] are reported. Apart from that, the laminar burning velocity is also enhanced [29, 31 32, 36].…”