Ignition of ADN-based monopropellants – Results of the european project RHEFORM

Paper number

IAC-17,C4,1,8,x39624

Author

Mr. Christian Hendrich, DLR (German Aerospace Center), Germany

Coauthor

Dr. Michele Negri, DLR (German Aerospace Center), Germany

Coauthor

Mr. Marius Wilhelm, Germany

Coauthor

Mr. Niklas Wingborg, Sweden

Coauthor

Mr. Linus Gediminas, Sweden

Coauthor

Mr. Leif Adelöw, Sweden

Coauthor

Mr. Corentin Maleix, CNRS, France

Coauthor

Mr. Pierre Chabernaud, France

Coauthor

Mr. Rachid Brahmi, France

Coauthor

Dr. Romain Beauchet, UNiversité de Poitiers, France

Coauthor

Dr. Yann Batonneau, France

Coauthor

Prof. Charles Kappenstein, France

Coauthor

Dr. Robert-Jan Koopmans, Austria

Coauthor

Mr. Sebastian Schuh, Austria

Coauthor

Mr. Tobias Bartok, Austria

Coauthor

Dr. Carsten Scharlemann, University of Applied Science Wiener Neustadt, Austria

Coauthor

Mr. K.S. Anflo, SSC, Sweden

Coauthor

Mr. Mathias Persson, Sweden

Coauthor

Mr. Wilhelm Dingertz, ECAPS AB, Sweden

Coauthor

Mr. Ulrich Gotzig, Airbus Safran Launchers, Germany

Coauthor

Dr. Martin Schwentenwein, Austria

Year

2017

Abstract

The proposed paper will give an overview of the project RHEFORM. RHEFORM is a European project in which 7 universities, research centers, and industries develop new technologies for replacing hydrazine with monopropellants based on ammonium dinitramide (ADN). 

The paper will be focused on one of the goals of RHEFORM: the development of igniters which require less power and allow a more prompt ignition compared to the pre-heated catalysts currently used. 
Currently ECAPS uses pre-heated catalysts on the 1 N thrusters for the ignition of the ADN-based propellant LMP-103S. The drawback of the current technology is that the power required for larger thrusters increases strongly; therefore for such applications an improved igniter would be beneficial. In the project two types of igniter are considered: improved catalyst igniters and thermal igniters.

Two catalyst supports are considered: granulates and monoliths. The support material should have an excellent resistance to thermal shocks and extreme temperatures, as well as a large specific surface area. To fulfill these requirements different types of silicon-doped aluminas and hexaaluminates have been synthetized and shaped in granulated form. The granules have been impregnated with different active phase and a preliminary selection was conducted in a batch reactor.
Monolithic supports have been 3D printed using the technology called Lithography-based Ceramic Manufacturing (LCM) developed from Lithoz, one of the project partners. Different designs of the monoliths have been considered. The monoliths have been coated with washcoat layers to increase the surface area. Procedures to deposit different kinds of washcoats have been developed. The active phases were deposited on the washcoats. A demonstrator has been developed to conduct a preliminary selection of the catalysts.

Different types of thermal igniters were considered in the project. Preliminary studies were conducted on laser and resistive ignition. No clear ignition was observed with these methods. Subsequently tests have been conducted with a demonstrator using a H2/O2 torch igniter. This igniter provides a large amount of power and allows multiple re-ignitions. In the tests conducted with the torch igniter vaporization of the propellant was observed, but no ignition. In order to achieve thermal ignition, variations of the demonstrator with improved combustion chambers have been designed, and are currently tested.

Abstract document

IAC-17,C4,1,8,x39624.brief.pdf

Manuscript document

IAC-17,C4,1,8,x39624.pdf (🔒 authorized access only).

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