Abstract:To compare the ignition performance of electric spark and laser induced spark ignition, experiments are carried out by using a modulated electric spark plug and a laser. The evolution of initial flame-kernel, ignition limits and flame propagation speed of these two different ignition modes are compared and analyzed under the same flow condition. The results show different shapes of the two initial flame kernels. The initial flame kernel of spark ignition is arc-shaped while laser ignition is petal shaped. Laser ignition has wider lean ignition limit than spark ignition within the same ignition energy. Flame propagation of laser ignition behind ignition position is faster than that of spark ignition under the same flow condition. Meanwhile, the differences of flame propagation speed between these two ignition patterns are much larger around stoichiometric ratio and at the flow velocity of 2.14 m/s.