Abstract: The invention relates to a pulse detonation engine and a method for initiating detonations in a pulse detonation engine. The pulse detonation engine (1) comprises a combustion chamber (2), an igniting device (3) and a fuel injection device (4) with a plurality of injection valves (5) arranged in the axial direction (20). The injection valves (5) are arranged in the longitudinal direction of the engine for sequence-controlled injection of fuel (6) into the combustion gases (7) remaining from the preceding detonation. This provides a mixture of fuel and free radicals that facilitates the forming of a detonation.