This contribution presents experimental and numerical investigations of the concept jet propulsion augmentation using bubble injection.A half-3D (D-shaped cylindrical configuration to enable optimal visualizations) divergent-convergent nozzle was designed,built,and used for extensive experiments under different air injection conditions and thrust measurement schemes.The design,optimization,and analysis were conducted using numerical simulations.The more advanced model was based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of the injected bubbles using our Surface Averaged Pressure (SAP) model.The numerical resultscompare very favorably with nozzle experiments and both experiments and simulations validation the thrust augmentation concept.For a properly designed nozzle and air injection system,air injection produces net thrust augmentation,which increases with the rate of bubble injection.Doubling of thrust was measured for a 50％ air injection rate.This beneficial effect remains at 50％ after account for liquid pump additional work to overcome increased pressure by air injection.