Collision Induced Loads in Pro-Injectors of ADDA Rocket Motors

Abstract:

The major improvement introduced by ADDA in space propulsion is the new Compound Rocket Motor concept (CRM), where, in contrast to the inefficient hybrid motors, the completion of combustion is very high. This new motor construction is also remarkable through its new injector type called pro-injector, currently under examination for patenting, with the capability of cutting out the dangerous reversed flow of the liquid component in a definitely short amount of time. The pro-injector device, quite critical when instable, high energy compounds like nitrous oxide are sprayed into the CRM combustion chamber, was designed, tested and successfully applied within the NERVA-ORVEAL project coordinated by the ADDA research team in cooperation with the AEROFINA partner. The results of the research regarding the pro-injector behavior are described. It was observed that unexpectedly high dynamic loads appear upon the seat of the pro-injector due to the collision-type motion when a shock wave in the combustion chamber develops. It is shown that such occurrence impedes application of fragile materials in the construction of the injector seat which otherwise would better serve the construction. Numerical simulations are presented as performed under rational assumptions regarding the mechanical behavior of mobile parts, in order to secure a smooth work of the device at the fast response required to downwind gas pressure shocks. The pro-injector proved being an innovative device currently submitted for patenting

• Periodical: Applied Mechanics and Materials (Volume 841)
• Pages: 292-297
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.841.292
• Online since: June 2016
• Authors: Radu Dan Rugescu
• Keywords: Injection Dynamics, Rocket Engines, Rocket Injectors, Space Propulsion

References

[1] K. Lohner, J. Dyer, E. Doran, Z. Dunn, B. Krieger, V. Decker, E. Wooley, A. Sadhwany, B. Cantwell, Th. Kenny, Design and Development of a Sub-scale N2O Monopropellant Gas Generator, 43rd AIAA, ASME, SAE, ASEE Joint Prop. Conf. &Exhibit, 8-11 July 2007, Cincinnati, OH.

DOI: 10.2514/6.2007-5463

[2] J. Dyer, E. Doran, Z. Dunn, K. Lohner, C. Bayart, A. Sadhwany, Design and Development of a 100 km Nitrous Oxide/Paraffin Hybrid Rocket Vehicle, 43rd AIAA, ASME, SAE, ASEE Joint Propulsion Conference and Exhibit, 8-11 July 2007, Cincinnati, OH.

DOI: 10.2514/6.2007-5362

[3] Galfetti, L., L.T. DeLuca, F. Severini, G. Colombo, L. Meda, G. Marra, Pre and post-burning analysis of nano-aluminized solid rocket propellants, European Conference for Aerospace Sciences (EUCASS), Session 5. 3, (2005).

DOI: 10.1016/j.ast.2006.08.005

[4] K. Lohner, J. Dyer, E. Doran, Z. Dunn, Fuel Regression Rate Characterization Using a Laboratory Scale Nitrous Oxide Hybrid Propulsion System, 42nd AIAA, ASME, SAE, ASEE Joint Propulsion Conference and Exhibit, 9 - 12 July 2006, Sacramento, California.

DOI: 10.2514/6.2006-4671

[5] Bruno Berger, Is nitrous oxide safe? Swiss Space Propulsion Laboratory, October (2007).

[6] ** Scaled Composites Accident Investigation Report, Inspection Nr. 310821103, Report ID 0950625, CA, Division of Industrial Relations, Occupational Safety and Health, Fresno, CA, (2008).

[7] Autodiverse Bi-propellant N2O rocket motor System for motive use, Knight Arrows, (2010).

[8] M. Sarian, D. Boiangiu, E. Caragheorghe, N. Enescu, St. Staicu, Eliza Haseganu, D. Rugescu, D. Coman, Problems in Mechanics for Engineers, Ed. Didactica si Pedagogica, Bucuresti, (1975).

[9] Rugescu, R., Retro-injector for instable liquids and manufacturing process, Patent Application 322/2014, Bulletin of Intellectual Property, Patent Section, no. 11/2014, Bucharest, Romania EU.