Laser ignition of a cryogenic thruster using a miniaturised Nd:YAG laser

Chiara Manfletti; Gerhard Kroupa

doi:10.1364/OE.21.0A1126

Optics Express
Vol. 21,
Issue S6,
pp. A1126-A1139
(2013)
•https://doi.org/10.1364/OE.21.0A1126

Laser ignition of a cryogenic thruster using a miniaturised Nd:YAG laser

Chiara Manfletti and Gerhard Kroupa

Open Access

Get PDF
Email
Share
Get Citation
Copy Citation Text
Chiara Manfletti and Gerhard Kroupa, "Laser ignition of a cryogenic thruster using a miniaturised Nd:YAG laser," Opt. Express 21, A1126-A1139 (2013)

Export Citation
- BibTex
- Endnote (RIS)
- HTML
- Plain Text
Citation alert
Save article

Abstract

An experimental study has been conducted to assess the feasibility of implementing laser ignition in cryogenic reaction and control and orbital manouvering thrusters. A experimental thruster with a single-coaxial injector element combustion chamber for testing with liquid oxygen/gaseous hydrogen and liquid oxygen/gaseous methane was designed for this purpose. Mapping tests conducted using a standard table top laser revealed that the minimum incident energies required for 100% reliable laser plasma and laser ablation ignition of liquid oxygen/gaseous hydrogen are 72 mJ and 14.5 mJ respectively. In addition, the miniaturised HIPoLas^® laser was mounted directly on the thruster and used as ignition system. This paper reports locations of energy deposition, levels of delivered energy and associated ignition probabilities obtained. The results indicate the feasibility of using a laser system for the direct ignition of reaction and control and orbital manouvering thrusters and highlight further investigations and developments necessary for the implementation of miniaturised laser systems for vacuum igntion of cryogenic propellants.

Full Article | PDF Article

More Like This

Laser ignited engines: progress, challenges and prospects

Geoff Dearden and Tom Shenton
Opt. Express 21(S6) A1113-A1125 (2013)

Ignition of an automobile engine by high-peak power Nd:YAG/Cr⁴⁺:YAG laser-spark devices

Nicolaie Pavel, Traian Dascalu, Gabriela Salamu, Mihai Dinca, Niculae Boicea, and Adrian Birtas
Opt. Express 23(26) 33028-33037 (2015)

Laser induced spark ignition of coaxial methane/oxygen/nitrogen diffusion flames

Xiaohui Li, Yang Yu, Xin Yu, Chang Liu, Rongwei Fan, and Deying Chen
Opt. Express 22(3) 3447-3457 (2014)

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.

Fig. 1 Experimental thruster geometry.

Download Full Size | PDF

Fig. 2 Optical path: table-top laser to experimental thruster.

Download Full Size | PDF

Fig. 3 Left: laser chamber; right: laser with protective housing.

Download Full Size | PDF

Fig. 4 Experimental thruster equipped with the HiPoLas^® laser.

Download Full Size | PDF

Fig. 5 Optical diagnotic set-up.

Download Full Size | PDF

Fig. 6 Spray image LOx/GH2 prior to ignition.

Download Full Size | PDF

Fig. 7 Combustion chamber flow field with HiPoLas^® laser plasma ignition regions for LOx/GH2.

Download Full Size | PDF

Fig. 8 Metal target location, laser beam focusing for ablation testing and plasma propagation for low energies delivered.

Download Full Size | PDF

Tables (5)

Table 1 Engine cycle numbers depending on application

View Table | View all tables in this article

Table 2 Experimental thruster geometry

View Table | View all tables in this article

Table 3 Laser system characteristics

View Table | View all tables in this article

Table 4 Propellant feed conditions and combustion chamber pressure levels during testing

View Table | View all tables in this article

Table 5 Oxygen-hydrogen energy deposition and ignition probabilities

View Table | View all tables in this article

Application	Engine Thrust	Cycles
Launcher RCS, Ariane 5	400 N	≈ 6000
Automatic Transfer Vehicle RCS	220 N	≈ 160000
Satellite apogee OMS	400 N	≈ 100
Herschel/Planck satellites OMS	20 N	93130

Combustion Chamber Geometry		Injector Geometry
Contraction ratio, ε_c	5.1	LOx post innter diameter, d₀	2.4 mm
Chamber diameter, d_c	60 mm	LOx post outer diameter, d₁	3.2 mm
Throat diameter, d_t	26.6 mm	H2 outer diameter, d₂	6.0 mm
Chamber length, l_c	138 mm	CH4 outer diameter, d₂	5.0 mm
Chamber length (cylindrical), l_cc	78 mm	Fuel sonic nozzles diameter, d_snl	2.0 mm

	Quantel YG981 E10	HiPoLas^®
Testing purpose	mapping	technology readiness assessment
Wavelength, λ	1064 nm, 532 nm	1064 nm
Pumping	flashlamp	diode pumped
Pulse length	6.5 ns	2.5 ns
Beam width	8 mm	2.5 mm
Energy	10–180 mJ ± 5 mJ	30 mJ ± 3 mJ
Pulse rate	10 Hz	40 Hz
Burst rate	-	100 Hz (max. 5 pulses)
Focusing lens	60 mm, 80 mm	36 mm
Focal spot size (calculated)	≈ 80 μm	≈ 50 μm
Lens material	Borosilicate (BK7)	Sapphire

Feed/Chamber Condition	Average Value
Oxygen feed pressure, p_fox	2.5 bar
Oxygen feed temperature, T_fox	90 K
Hydrogen feed pressure, p_GH2	12 bar
Hydrogen feed temperature, T_GH2	224 K
Liquid oxygen injection velocity v_ox	8 m/s
Gaseous hydrogen Mach number, M_GH2	2.8
Gaseous hydrogen flow speed at M_GH2 = 2.8, v_GH2	3206 m/s
Velocity ratio (fuel/oxidiser), v_R	407
Gaseous hydrogen flow sonic speed, v_GH2s	1145 m/s
Chamber pressure prior to priming, p_cc1	approx. 20–75 mbar
Chamber pressure prior to ignition - LOx/GH2, p_cc2	450 mbar
Steady state combustion pressure p_cc3	1.5–1.7 bar

Region	Laser	Position, (x, y)	Incident Energy	Ignition Probability	Sample Size
Region B₂	HiPoLas^®	(11–15 mm, 4–7 mm)	30 ± 3 mJ	17%	30
Region B₂	table-top	(12–16 mm, 5–8 mm)	72 mJ ± 5 mJ 54 mJ ± 5 mJ	100% 50%	53
Region C	HiPoLas^®	(32–34 mm, 8 mm)	30 ± 3 mJ	33%	9
Region C	table-top	(57–60 mm, 10–17 mm)	66 mJ ± 5 mJ	100%	7

Abstract

Cited By

Figures (8)

Tables (5)

Optics Express