DiscThruster Is a Hyper-Efficient Pressure-Thrust Driven Air Breathing and Rocket Propulsion Concept, the Flipside of Conventional Momentum-Thrusters. Testing Shows Potential.

DiscThruster Concept—Hyper Efficient Pressure-Thrust Driven Air Breathing and Rocket Propulsion Historically, propulsion research has focused on maximizing momentum-thrust and minimizing pressure-thrust for optimal engine performance. The DiscThruster™ concept reverses this paradigm by prioritizing pressure-thrust, resulting in conceptual hyper efficient air-breathing and rocket engines. DiscThruster channels low-velocity fluid through a converging-only nozzle, achieving sonic choking at the exit plane that generates pressure-thrust while minimizing momentum-thrust. This approach avoids the large loss of kinetic energy leaving the engine’s control volume in the form of high velocity exhaust gases that cannot perform any additional work. For example, a two-phase mixture of liquid bismuth-tin eutectic and gaseous ethanol at 325℃ (617℉) chokes at just 17.6 m/s (57.7 ft/s) at a pressure of 40 bar (580 psi). The high-density eutectic in a two-phase mixture promotes very low sonic velocities for effective fluid capture and recycling. This concept focuses on producing a 129 kN (29,000 lbf) thrust class DiscThruster engine for commercial narrow body aircraft, powered by a small conventional air breathing turboshaft engine. The rocket engine version uses the same DiscThruster core but substitutes the small turboshaft engine with an electric motor and battery combination to power the space launch vehicle to orbit. Sized at < 1.0 m (< 3.3 ft) in diameter, DiscThruster’s disc is relatively compact to produce required thrust. Experimental hardware testing with air-water mixtures at room temperature and pressures up to 6.9 MPa (1,000 psi) validated the concept’s ability to empirically create and measure two-phase flow sonic choking in a rocket nozzle and demonstrate fluid exiting the nozzle can be captured and recycled using centripetal force by means of high rpm spinning blades. DiscThruster’s closed-form analysis predicts hyper efficient pressure-thrust airbreathing and rocket propulsion concepts will exceed their goals of reducing fuel burn by 50% when benchmarked against modern high bypass turbofan engines, and a 2X or doubling in specific impulse over high performance liquid rocket engines. Since predicted DiscThruster performance exceeded goals, a knock down factor (added margin for uncertainty) was included to match goals.