A pulse combustor system , comprising: a pulse combustor , comprising: a combustion chamber defining an internal space , a conduit having a first central longitudinal; axis , and the conduit having a first end in fluid communication with the internal space and a second end in fluid communication with an environment outside of the pulse combustor, and a fuel injector configured to inject fuel into the internal space of the combustion chamber; and a duct that forms an augmenter having a second central longitudinal axis , the duct having a diameter greater than the diameter of the conduit and defining: a first opening disposed at a first end of the second central longitudinal axis, and a second opening disposed at a second end of the second central longitudinal axis opposite the first end, wherein the pulse combustor system has an average operating frequency, indicating an average number of combustion events per second during operation of the pulse combustor system; and wherein the second central axis of the duct is substantially aligned with the first central axis of the conduit, and the first opening of the duct is disposed adjacent to the second end of the conduit, wherein the duct has a length that is about one quarter of a wavelength in length along the second central longitudinal axis, wherein the wavelength corresponds to the average operating frequency. a pulse combustor , comprising: a combustion chamber defining an internal space , a conduit having a first central longitudinal; axis , and the conduit having a first end in fluid communication with the internal space and a second end in fluid communication with an environment outside of the pulse combustor, and a fuel injector configured to inject fuel into the internal space of the combustion chamber; and a combustion chamber defining an internal space , a conduit having a first central longitudinal; axis , and the conduit having a first end in fluid communication with the internal space and a second end in fluid communication with an environment outside of the pulse combustor, and a fuel injector configured to inject fuel into the internal space of the combustion chamber; and a duct that forms an augmenter having a second central longitudinal axis , the duct having a diameter greater than the diameter of the conduit and defining: a first opening disposed at a first end of the second central longitudinal axis, and a second opening disposed at a second end of the second central longitudinal axis opposite the first end, wherein the pulse combustor system has an average operating frequency, indicating an average number of combustion events per second during operation of the pulse combustor system; and wherein the second central axis of the duct is substantially aligned with the first central axis of the conduit, and the first opening of the duct is disposed adjacent to the second end of the conduit, wherein the duct has a length that is about one quarter of a wavelength in length along the second central longitudinal axis, wherein the wavelength corresponds to the average operating frequency. a first opening disposed at a first end of the second central longitudinal axis, and a second opening disposed at a second end of the second central longitudinal axis opposite the first end, wherein the pulse combustor system has an average operating frequency, indicating an average number of combustion events per second during operation of the pulse combustor system; and wherein the second central axis of the duct is substantially aligned with the first central axis of the conduit, and the first opening of the duct is disposed adjacent to the second end of the conduit, wherein the duct has a length that is about one quarter of a wavelength in length along the second central longitudinal axis, wherein the wavelength corresponds to the average operating frequency. <EOS>