A control volume analysis of a novel dynamic intake system known as the Atlantis Intake System (AIS) used to supply air and fuel to a ramjet engine has been performed. The AIS, being developed by Atlantis Research Labs, is based on the work of Eugene Gluhareff. Since Gluhareff ’s pressure jet design was originally intended for tip propulsion of helicopter rotor blades, it has been modified to work with a ramjet engine. The AIS utilizes three inlet stages where an under-expanded fuel jet is injected to draw in ambient air, producing a high velocity reactive mixture. Deceleration in a supersonic diffuser results in a high stagnation pressure gas mixture entering the combustion chamber. A method for the prediction of downstream mixture properties and resulting engine performance is derived for both static and dynamic operation. Performance is assessed in terms of specific impulse. The prediction models are validated against numerical simulations that replicate flow conditions associated with the AIS. Means of entrainment are studied through an analysis of the numerical simulation results.