CDW Continuious Detonation Wave Engine

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Continuous Detonation Wave Engine

F. [email protected]

RTO / AVT / VKI Lecture SeriesAdvances on Propulsion Technology for High-Speed Aircraft

March 12-15, 2007

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Summary

• Interest of CDW process

• Basic experiments

• System study and engine sizing

• Key technology points & experimental evaluation

- Thrust vectoring

- Heat fluxes and cooling system

- Operation in space environment

• Numerical simulation

• Engine demo

• Conclusion

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• What is a CDWE ?• Annular combustion chamber

with a center body

and injection wall

• Engine where the combustion

is achieved by transverse

detonation waves

Injection

Detonationwave

Expansion ofdetonation products

Interest of the CDW process

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• Why trying to use a detonation ?• Comparison of H2+O2 stoichiometric mixture constant-pressure

combustion and detonation

• So it is possible for a given injection pressure to gain some specific impulse, or to decrease the injection pressure

Initial state Final state

5 MPa300 K

5 MPa3635 K

1515 m.s-1

107 MPa4497 K

1667 m.s-1

5 MPa3866 K

1575 m.s-1

0.26 MPa300 K

Final state

Detonation

Detonation

Constant pressure

Speed of sound+ 10 %


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• Interest of a CDWE• Detonation instead of deflagration

• Continuous flow

• High mass flow rate (up to1500 kg.m-2.s-1 testedin LIH combustion chamber)

• Flow structure• 2D unsteady flow

• Axial (Z) and transverse (X) velocity

• Transition from subsonic tosupersonic in the combustionchamber (NLM)

Reference : TD Wave axis !


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PDE : CDWE :Pulse Detonation Engine Continuous Detonation

Wave Engine Injection

Detonationwave

Expansion ofdetonation products

DCJProduits dedétonation Gaz frais

DWE Concepts under consideration at MBDA (1/2)

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PDESimple airbreathing engine for low cost subsonic vehicles (small missiles, UAVs…) particularly for very demanding mission in terms of thrust range

CDWELiquid Rocket Enginecompact, aerospike, lower feeding pressure, thrust vectoring

Simplified Ramjet Enginewith short ramcombustor & operating from Mach 0+

TurbojetImproved performance (iso-volume / iso-pressure cycle)simplified system by reducing compression system

DWE Concepts under consideration at MBDA (2/2)

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PDEBasic studies performed with LCD in Poitiersand Russian Institutes

Ejector PDE Detonation ignition enhancementRadicals seeding (electric discharge)Atoms vibrational levels exitation by laser

PDE demonstratorDeveloped by MBDA in cooperation with DSO SingaporePossible flight test program within a few yearsusing a UAV like vehicle

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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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Initial validation of CDWE principle

• Experiments performed in CC with innerdiameter of 50 mm, 100 mm and 280 mm

• Homogeneous (gas / gas) and heterogeneous (liquid / gas) mixtures studied

• Detonation regime obtained in 100 mm diameter CC with GH2/LOx

• Detonation regime obtained in 330 mm diameter CC with kerosene/air

• High thrust density achieved in small CC(275 daN for a 50 mm inner diameter

kerosene/GO2 engine)

Basic experiments (cooperation with Lavrentiev Institute)

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• Key design parameters• D : TDW velocity• l : distance between two detonation waves

• Height of the fresh mixture function of the detonation cell size• Experimentally, it was found that the CC length

should be longer than 0.8 l (for a transition fromsubsonic to supersonic inside the CC)

• If the CC length is shorter than 0.8, thedetonation phenomenon could be unstable

• The frequency of the engine is D/l, typically several kHz• It was found experimentally that 4~5 detonation waves could exist in a

100 mm ID combustion chamber using GH2-GO2 mixture (l < 80 mm)• The minimum CC length for GH2-GO2 mixture is near 70 mm

Basic experiments (cooperation with Lavrentiev Institute)

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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Example of LRE • Due to the annular combustion

chamber, an aerospike or plugnozzle is the more convenientsolution,

• The volume of the nozzle couldbe used for the engine equipments bay,

• The engine very high operating frequency is best suited to space launchers than a PDE,

• Anticipated specific impulse with a stoichiometric H2-O2 mixture,

0.022

0.034

0.101

ΔJ/J*

137

127

98

J*, (kN)

140

131

108

J, (kN)

415

383

296

I*, sec

4241.620.007338.52.15

3961.490.039910.11.1

3261.100.63371.330.4

I, secvn/vzpn/pSn/S1dn (m)

System study and engine sizing

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• Due to the annular combustion chamber, an aerospike or plugnozzle is the more convenient solution

• The volume of the nozzle can be used for the engine equipments bay or tank

• The engine very high operating frequency is best suited to space launchers than a PDE

• The feeding system can be very simple

with reduced pressure

• Such engine would be perfectly

integrated in a NEO vehicle taking

fully advantage of the airbreathing

engine nozzle while being very simple

to open and close

System study and engine sizing

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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Thrust vectoring capability• To gain some advantages of the

flow heterogeneity inside the CC

• If we increase locally the mass flowrate, we will increase the local pressure

• Local mass flow rate andequivalence ratio effect havebeen investigated in a 100 mmdiameter CC

• It is possible to increase the localpressure by as much as 30 % insuch a small CC, larger increasecould be possible in bigger CC

• Additional investigations (on nozzle effect) still to be done

0°

90°

180°

270°

Mass flow = 1 Mass flow = 2

Key technology points & experimental evaluation

p1

p2

p3

p4

p5

p6

p7

0,6

0,8

1

1,2

1,4

0 1 2 3 4 5 6 7 8

Probe numberRe

lativ

e pr

essu

re

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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Heat load• The heat fluxes in a CDWE

are higher than in a PDE

• For a small-scale, metallicengine the wall temperaturereached 1000 K in lessthan 0.3 s

• The heat fluxes are locatednear the injection wall

• With metallic structures

(wall temp limited to 800 K)

the mean measured heat flux is roughly 15 – 17 MW.m-2

• Interest of composite structures (C/SiC) able to sustain up to 1800 K


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• Composite materials compatibility• Metallic structures cooling

is very challenging• Proven solution used in

LRE (like film cooling), arenot expected to work easilyin CDWE due to shock / boundary layer interaction

• 2 composite C/SiC parts manufactured and successfully tested in LIH 100 mm chamberduring a series of short duration (0,5 s) test

• Further works to be done to taking into account more severe test conditions


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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Operation in space environment• LIH 100 mm chamber

• 0.5 m3 vacuum tank initial pressure 6.000 Pa

• Blasting copper wires for initiating the detonation

• GH2 (2.5 to 0.16 MPa) and LO2 (1.1 to 0.5 MPa) corresponding with 57 to 21 kg/s/m² of specific mass flow (10 times less than previously)

• Less than 1 J energy needed to start a TDW in a wide range of equivalence ratio (0.5 to 1.7)


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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Preliminary simulations with FLUCEPA code• 9 steps kinetic model for H2/O2 combustion

• Single detonation wave with forced ignition

• Code robustness ensured against large pressure and velocity gradients

Numerical simulation

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• 2D Euler simulation from ICARE Lab• 2D Euler simulation

• H2/O2 chemistry model using 6 species and 7 reactions

• Periodicity conditions along the vertical boundaries

• ~ 600.000 cells grid


100 mm

60 m

m

40 m

m

Con

stan

t wid

th

20 m

m

expa

nsio

n

x

y

periodicity periodicity

injection

exit

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• 2D Euler simulation from ICARE Lab - results


Circumferential speed

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• 2D Euler simulation from ICARE Lab - results


Axial speed

Axial Mach number

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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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Ground Demonstration Engine

1 2

3

Modular engine that couldbe used for thrust andspecific impulsemeasurement• (1) Injection wall

• (2) Actively cooled external jacket

• (3) Variable lengthinner cylinder corewith aerospike nozzle

• Additional bell nozzle will be used for thrust optimization

• Designed to allow the testing of composite (C/SiC) engine parts

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• Combustion chamber outer diameter : 350 mm

• Inner diameter : 280 mm

• Combustion chamber height : 35 mm

• Feed pressure : between 1.5 MPa and 2.5 MPa

• Combustion chamber mean pressure : near 0.5 MPa

• Mixture used : - GH2 + LO2 (1 sec test, performance measurement, transient conditions)

- GH2 + GO2 (10 sec test, performance measurement, static conditions)

- GH2 + air (several minutes test, material endurance testing)

- LHC + air

• Mass flow rate :- Hydrogen : 1.5 kg.s-1

- Oxygen : 12 – 14 kg.s-1


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Thermal behaviour cooled structure

Generated vibration environment

Successive detonation waves self-ignition process

Thrust vector & associatedmoments

Injection and mixing

Mechanical behaviour of cooled structure(high frequency shocks)

Stability Domain

Generated acousticenvironment

Skin friction forces Jet direction and

swirl effect

non-symmetric feeding propagation (chamber & nozzle)

Thermal behaviour cooled structure

Generated vibration environment

Successive detonation waves self-ignition process

Thrust vector & associatedmoments

Injection and mixing

Mechanical behaviour of cooled structure(high frequency shocks)

Stability Domain

Generated acousticenvironment

Skin friction forces Jet direction and

swirl effect

non-symmetric feeding propagation (chamber & nozzle)


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Summary





- Thrust vectoring




• Engine demo

• Conclusion

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• Conclusion• Since a few years, MBDA France is leading a R&T program on CDWE in

cooperation with Lavrentyev Institute of Hydrodynamics of Novosibirsk

• Experiments were performed by the LIH with CC of 50 mm, 100 mm and 280 mm inner diameter

• Homogeneous (gas / gas) and heterogeneous (liquid / gas) mixture were studied

• Those experiments were focused on key technology points needed to evaluate the global concept of a CDWE

• First test series was successfully performed with composite material (C/SiC) engine parts

• Further development could be the development of a large scale engine demo

Design of a CDW Engine for space Application

Documents

CDW Continuious Detonation Wave Engine