Thrust Augmentation Nozzle (TAN) Concept for Rocket Engine Booster Applications
- Paper number
IAC-05-C4.3.03
- Author
Mr. Scott Forde, Aerojet, United States
- Coauthor
Mr. Todd Neill, Aerojet, United States
- Year
2005
- Abstract
A unique means of increasing sea level thrust in a liquid rocket booster engine is possible using Aerojet’s patented Thrust Augmented Nozzle (TAN) concept. Aerojet has used its knowledge gained from hypersonic scramjet research to inject and burn propellants into the diverging region of the rocket engine nozzle that increases the nozzle pressures and therefore significantly increasing the sea level thrust without seriously impacting the engine’s specific impulse. The TAN concept is scalable over a wide range of thrust class engines, engine cycle schemes, propellant combinations and can also provide differential injection into the circumference of the divergent nozzle and provide thrust vector control capability thereby giving the vehicle designers new options for the liquid propulsion system. The vehicle benefits provide by the TAN technology are wide ranging. These benefits include reducing the number of engines therefore leading to reliability improvements, lower costs and improved vehicle packaging. The increased exit pressure when TAN is activated allows for larger nozzle area ratios for higher vacuum specific impulse. A higher thrust-to-weight of the engine can reduce the engine weight and increase vehicle payload capability. Possibly the most important benefit of TAN is increased engine system reliabilities by operating the engine core at a reduced chamber pressure and making up the required thrust by operating TAN. For vehicles that require throttling for either vehicle acceleration or dynamic pressure limits, turning off TAN simplifies or eliminates the main engine throttling need, resulting in improved TPA efficiencies and a simplified engine system design. TAN can be used to compensate engine thrust in engine-out conditions for increased mission success and safe vehicle returns on multi-engine vehicles. Using TAN for thrust vector control eliminates the weight and complexity of the conventional approach of moving the engine assembly with linear actuators and gimballed propellant lines. Hot fire Proof-of-Concept tests were conducted with single propellant and dual propellant injection into an 9KN (2000 lbf) non-optimized thrust gaseous oxygen / gaseous hydrogen rocket engine. A 28 percent increase in sea level thrust was demonstrated using a 25:1 expansion ratio nozzle with the engine core operating at a chamber pressure of 6.9 MPa (1000 psia). Further development of TAN is underway that will address nozzle/injector integration issues, characterize liquid injection plus nozzle heat flux, thrust augmentation ranges (up to 2-3 times core engine thrust) and conduct engine system and mission optimization trades. Calculations of nozzle performance and wall pressures were made using a commercial computational fluid dynamics program. The results of calculations with and without thrust augmentation flow are presented and compared with test data. There is good agreement between calculated and measured quantities, including augmentation thrust. The paper will describe the TAN concept, the vehicle benefits and status of the TAN technology.
- Abstract document
- Manuscript document
IAC-05-C4.3.03.pdf (🔒 authorized access only).
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