US4800716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Efficiency arcjet thruster with controlled arc startup and steady state attachment
Assignee: Aerojet Rocketdyne Inc
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Filing: 1986-07-23
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Granted: 1989-01-31
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Expires: 2006-07-23
Abstract
Abstract An improved efficiency arcjet thruster has a constrictor and electrically-conductive nozzle anode defining an arc chamber, and an electrically-conductive rod having a tip spaced upstream from the constrictor and defining a cathode spaced from the anode by a gap generally coextensive with the arc chamber. An electrical potential is applied to the anode and cathode to generate an electrical arc in the arc chamber from the cathode to anode. Catalytically decomposed hydrazine is supplied to the arc chamber with generation of the arc so as to produce thermal heating and expansion thereof through the nozzle. The constrictor can have a electrically insulative portion disposed between the cathode tip and the nozzle anode, and an electrically-conductive anode extension disposed along the insulative portion so as to define an auxiliary gap with the cathode tip substantially smaller than the gap defined between the cathode and nozzle anode for facilitating startup of arc generation. The constrictor can also include an electrically-conductive electrode with a variable electrical potential to vary the shape of the arc generated in the arc chamber. Also, the cathode is mounted for axial movement such that the gap between its tip and the nozzle anode can be varied to facilitate a generally nonerosive generation of the electrical arc at startup and reliable steady state operation. Further, the arc chamber can have a nonparallel subsonic-to-supersonic transition configuration, or alternatively solely a nonparallel supersonic configuration, for improved arc attachment.
Inventors
- 👤 William W. Smith
- 👤 Steven C. Knowles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:51
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/40; B64G1/411; B64G1/415
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode, said constrictor including a generally annular-shaped portion formed of electrically insulative material disposed in the subsonic zone between said cathode tip and said nozzle anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; and (d) means for supplying preheated constituent gases of a catalytically decomposed monopropellant to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said gases in said chamber and expansion thereof through said nozzle.
Claim 2
Dependent Claim
169 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode, said constrictor including a generally annular-shaped portion formed of electrically insulative material disposed in the subsonic zone between said cathode tip and said nozzle anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; and (d) means for supplying preheated constituent gases of a catalytically decomposed monopropellant to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said gases in said chamber and expansion thereof through said nozzle.
Claim 3
Dependent Claim
85 words
The arcjet thruster as recited in claim 1, wherein said constrictor includes: (e) means defining an electrically-conductive extension of said nozzle anode disposed in a fixed position along said insulative material of said constrictor, exposed to said arc chamber and axially extending between said cathode tip and nozzle anode so as to define an auxiliary gap with said cathode tip substantially smaller than said gap defined between said cathode and nozzle anode for facilitating startup of said arc generated from said cathode to said anode.
Claim 4
Dependent Claim
174 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said are chamber form said cathode to said anode; (d) means for supplying preheated constituent gases of a catalytically decomposed monopropellant to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said gases in said chamber and expansion thereof through said nozzle; and (e) an electrically-conductive electrode disposed therein; and means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
Claim 5
Dependent Claim
174 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said are chamber form said cathode to said anode; (d) means for supplying preheated constituent gases of a catalytically decomposed monopropellant to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said gases in said chamber and expansion thereof through said nozzle; and (e) an electrically-conductive electrode disposed therein; and means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
Claim 6
Dependent Claim
237 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; and (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; (e) said constrictor including (i) a generally annular-shaped portion formed of electrically insulative material disposed between said cathode tip and said nozzle anode, and (ii) means defining an electrically-conductive extension of said nozzle anode disposed in a fixed position along said insulative material of said constrictor, exposed to said arc chamber and axially extending between said cathode tip and nozzle anode so as to define an auxiliary gap with said cathode tip substantially smaller than said gap defined between said cathode and nozzle anode for facilitating startup of said arc generated from said cathode to said anode.
Claim 7
Dependent Claim
237 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; and (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; (e) said constrictor including (i) a generally annular-shaped portion formed of electrically insulative material disposed between said cathode tip and said nozzle anode, and (ii) means defining an electrically-conductive extension of said nozzle anode disposed in a fixed position along said insulative material of said constrictor, exposed to said arc chamber and axially extending between said cathode tip and nozzle anode so as to define an auxiliary gap with said cathode tip substantially smaller than said gap defined between said cathode and nozzle anode for facilitating startup of said arc generated from said cathode to said anode.
Claim 8
Dependent Claim
270 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define and anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; and (e) said constrictor including: (i) a generally annular-shaped portion formed of electrically insulative material disposed between said cathode tip and said nozzle anode, and (ii) means defining an electrically-conductive extension of said nozzle anode disposed in a fixed position along said insulative material of said constrictor, exposed to said arc chamber and axially extending between said cathode tip and nozzle anode so as to define an auxiliary gap with said cathode tip substantially smaller than said gap defined between said cathode and nozzle anode for facilitating startup of said arc generated form said cathode to said anode, and (iii) means defining an electrically-conductive electrode disposed therein; and means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
Claim 9
Dependent Claim
270 words
In an arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define and anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; and (e) said constrictor including: (i) a generally annular-shaped portion formed of electrically insulative material disposed between said cathode tip and said nozzle anode, and (ii) means defining an electrically-conductive extension of said nozzle anode disposed in a fixed position along said insulative material of said constrictor, exposed to said arc chamber and axially extending between said cathode tip and nozzle anode so as to define an auxiliary gap with said cathode tip substantially smaller than said gap defined between said cathode and nozzle anode for facilitating startup of said arc generated form said cathode to said anode, and (iii) means defining an electrically-conductive electrode disposed therein; and means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
Claim 10
Dependent Claim
173 words
In a arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; (e) said constrictor including an electrically-conductive electrode disposed therein; and (f) means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
Claim 11
Dependent Claim
173 words
In a arcjet thruster, the combination comprising: (a) means forming a tandemly-arranged constrictor and nozzle which together define an arc chamber, at least said nozzle being electrically conductive to define an anode; (b) an elongated member having a tip disposed adjacent to and spaced upstream from said constrictor, said member being electrically conductive to define a cathode spaced from said anode by a gap generally coextensive with said arc chamber; (c) means for applying an electrical potential to said anode and cathode so as to generate an electrical arc in said arc chamber from said cathode to said anode; (d) means for supplying a flowing gas to said arc chamber via said constrictor concurrently with the generation of said arc so as to produce thermal heating of said flowing gas in said chamber and expansion thereof through said nozzle; (e) said constrictor including an electrically-conductive electrode disposed therein; and (f) means for varying the electrical potential of said electrode so as to vary the shape of said arc generated in said arc chamber.
References Cited (Backward Citations)
US2850662A
Cited
FR1368255A
Cited
US3359734A
Cited
US3353060A
Cited
US3425223A
Cited
US3651644A
Cited
US3692431A
Cited
US4370539A
Cited
US4577461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |