Atomizing jets and dense sprays of practical interest to liquid-fed combustion systems have yielded few quantitative
measurements due to their optical opacity. This work focuses on the measurement of the intact-liquid-core length of
jets issuing from shear-coaxial-type rocket engine injectors. Real-time x-ray radiography, capable of imaging
through the dense two-phase region surrounding the liquid core, is used to make the measurements. The intact-liquid-core length data have been obtained and interpreted to illustrate the effects of chamber pressure (gas density), injected gas and liquid velocities, and cavitation. The results clearly show that the effect of cavitation must be considered at low chamber pressures since it can be the dominant breakup mechanism. A correlation of intact-core length in terms of gas-to-liquid density ratio, liquid jet Reynolds number, and Weber number is suggested for the regime where cavitation is not a factor.