Propellants, in particular for the propulsion of vehicles such a

Details Propellants, in particular for the propulsion of vehicles such a Propellants, in particular for the propulsion of vehicles such a

1995-10-06

1998-11-17

Miller, Edward A.

Explosive and thermic compositions or charges

Structure or arrangement of component or product

Solid particles dispersed in solid solution or matrix

149 194, 149 1992, 149 89, C06B 4510

Patent

active

058379304

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to propellants, in particular for the propulsion of vehicles such as, for example, rockets, of the type comprising at least an oxidizer, a fuel and an energetic binder.
Requirements for high performance propellants or mixtures of propellants exist generally in many industrial fields, in particular in the aerospace field, where these mixtures must be capable not only of being durably stored, for example in a space vehicle, in order to be employed at any time to modify its trajectory, but also to be used to launch it.
Hitherto, extensive use has been made of cryogenic mixtures based on liquid oxygen and hydrogen, which are found to be highly effective for feeding rocket engines which, in particular, place telecommunication satellites and other space vehicles in orbit.
However, these cryogenic mixtures are difficult to keep stored and their handling is hazardous and frequently a source of accidents.
To overcome these disadvantages it is known to replace these cryogenic mixtures with mixtures of propellants consisting at least of an oxidizing agent and of a fuel agent, which can be stored easily and durably without requiring special safety conditions, but these mixtures generally offer performances which are greatly inferior to those offered by cryogenic mixtures.
To make a comparison by considering one of the parameters which characterizes these mixtures, namely the specific impulse (which will be defined later), this impulse is higher than 4000 m/s in the case of cryogenic mixtures whereas, it is only approximately 3000 m/s in the case of a mixture of propellants consisting of nitrogen tetroxide (N.sub.2 O.sub.4) and monomethylhydrazine (N.sub.2 H.sub.3 CH.sub.3), for example.
Under these conditions, if a velocity of 2000 m/s is necessary to put a space vehicle into orbit or to modify its trajectory, half the mass of the space vehicle must be dedicated to a propellant agent capable of producing a specific impulse of 2943 m/s. On the other hand, with a specific impulse of 4415 m/s, the mass of the propellant agent would be reduced to 37.5%, thus offering a mass saving of approximately 12.5%, which could be advantageously employed, for example, for launching telecommunication satellites. In other words, by increasing the specific impulse it is possible to reduce the mass of the propellant agent and to increase the payload carried onboard the space vehicle. To give an example, in the case of a 2000 kg space vehicle, the payload increase is of the order of 250 kg.
Given that only cryogenic mixtures made it possible to obtain specific impulses higher than 4000 m/s, attempts have been made to increase the energetic power of mixtures of propellants and thus to preserve the advantages which they offer where their storage is concerned.
U.S. Pat. No. 4,938,814, in the name of the Applicant Company discloses a heterogeneous mixture of propellants comprising at least a solid oxidizer consisting of hydrazinium nitroformate, a fuel consisting of di- or pentaborane, and an energetic binder consisting of polyglycidyl azide (C.sub.3 H.sub.5 N.sub.3 O).sub.n or of poly-3,3-bis(azidomethyl)oxetane (C.sub.4 H.sub.5 N.sub.6 O).sub.n.
In addition U.S. Pat. No. 4,950,341, also in the name of the Applicant Company discloses a solid mixture of propellants comprising at least an oxidizer chosen from the group which comprises hydrazinium nitroformate, nitronium perchlorate and ammonium perchlorate, a fuel chosen from the group which comprises boron, aluminum and aluminum hydride, and an energetic binder chosen from the group which comprises polyglycidyl aside and poly-3,3-bis(azidomethyl)oxetane.
The mixtures according to U.S. Pat. No. 4,938,814 and U.S. Pat. No. 4,950,341 provide propellants agents which have performances close to those of cryogenic mixtures. Kyokaishi 27(3), p.169-173 (1966)! to employ, in the case of composite fuels, a polymeric binder consisting of a fuel resin synthesized by addition polymerization of glycol and of glycidyl nitrate in the presence of a Friedel and Crafts catalyst to

REFERENCES:
patent: 3657028 (1972-04-01), Pannell
patent: 3658608 (1972-04-01), Low
patent: 3708359 (1973-01-01), Low
patent: 3844855 (1974-10-01), Plomer et al.
patent: 3870578 (1975-03-01), Nichols
patent: 4707540 (1987-11-01), Manger et al.
patent: 4938814 (1990-07-01), Schoyer et al.
patent: 4950341 (1990-08-01), Schoyer et al.

Affiliated with

Also associated with

Rating

Propellants, in particular for the propulsion of vehicles such a does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Propellants, in particular for the propulsion of vehicles such a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Propellants, in particular for the propulsion of vehicles such a will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-886248