A scramjet includes a converging inlet, a combustor configured to introduce a fuel stream into an air stream in a combustion chamber and to combust the fuel air mixture stream to create an exhaust stream, and a diverging exit nozzle configured to accelerate the exhaust stream. The combustor includes a fuel injection system including at least one arcjet. A method of creating thrust for an aircraft includes compressing a supersonic incoming air stream in a converging inlet, injecting a fuel stream into the air stream in a combustion chamber to create a fuel air mixture stream, igniting the fuel air mixture stream to create an exhaust stream, and exhausting the exhaust stream from a diverging exit nozzle. The injecting the fuel stream into the air stream includes injecting the fuel stream at a fuel speed sufficient to create shear between the fuel stream and the air stream.