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Development of a Compact Liquid Fueled Pulsed Detonation Engine with Pre-detonator

AcknowledgementsAcknowledgements: : This study is made possible by funding fromMechanical and Aerospace Engineering Department, UT ArlingtonandThe National Science Council, Taiwan, ROC

•Philip K. Panicker

Aerodynamic Research Center, University of Texas at Arlington, Arlington, Texas, 76019

•Jiun-Ming (Jimmy) LiInstitute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan, 701, Republic of China

•Frank K. Lu•Donald R. Wilson

ARC, MAE Department, UT Arlington, Arlington, Texas, 76019

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AgendaPast PDE research at ARCPast PDE research at ARCObjectives of present PDE designObjectives of present PDE designPrePre--detonatordetonator3030˚̊ Smooth Area Change NozzleSmooth Area Change NozzleMain CombustorMain CombustorFuel and Gas Injection ValvesFuel and Gas Injection ValvesLiquid FuelLiquid Fuel--Air Mixing ChamberAir Mixing ChamberDiagnosticsDiagnosticsComplete ApparatusComplete ApparatusTest ProgramTest Program

ConclusionConclusion

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Past Detonation and PDE studies at ARCPast Detonation and PDE studies at ARCStanley, Steven Bradley, "Experimental Investigation of Factors Influencing the Evolution of a Detonation Wave," Master's Thesis, Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, Arlington, TX, 1995.Burge, Karl Ramon, "Pulse Detonation - Detonation Continuance in Fuel-Air Regions," Master Thesis, Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, Arlington, TX, 1995.Munipalli, R., Shankar, V., Wilson, D.R., Kim, H., Lu, F.K., and Hagseth P.E. "A pulse detonation based mulitmode engine concept,"AIAA Paper 2001–1786, 10th AIAA/NAL/NASDA/ISAS International Space Planes and Hypersonic Systems and Technologies Conference, Kyoto, Japan, April 24–27, 2001Wilson, D.R., Lu, F.K., Kim, H., and Munipalli, R., "Analysis of a pulsed normal detonation wave engine concept," AIAA Paper 2001–1784, 10th AIAA/NAL/NASDA/ISAS International Space Planes and Hypersonic Systems and Technologies Conference, Kyoto, Japan, April 24–27, 2001Meyers, J. M., "Performance Enhancements on a Pulsed Detonation Rocket," Master's Thesis, Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, Arlington, TX, 2002.

Presently there are Computational and Experimental studies on Pulse Detonation Engines and Applications at the ARC.

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20002000--20032003

Lu, F.K., Meyers, J.M. and Wilson, D.R., “Experimental study of propane-

fueled pulsed detonation rocket,”

AIAA Paper 2003–

6974, 12th AIAA International Space Planes and Hypersonic Systems and Technologies, December 15–18, 2003, Norfolk, Virginia

•Propane + O2 mixture

•5 to 20 Hz detonation cycles

•Shchelkin spiral

•High energy arc ignition

•Rotary valve system

•CJ detonation achieved briefly at low frequencies but not at the higher frequencies. This was attributed to improper mixing at higher frequencies.

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High Energy Arc Ignition to Initiate DetonationHigh Energy Arc Ignition to Initiate DetonationRequires bulky electrical circuit components.Requires bulky electrical circuit components.Transformers, capacitor banks are heavy and Transformers, capacitor banks are heavy and impractical for flight weight model.impractical for flight weight model.Power generation to initiate arcs will deplete enginePower generation to initiate arcs will deplete engine’’s s available power output.available power output.Most of the power is wasted electrically when arc Most of the power is wasted electrically when arc current flows to ground.current flows to ground.Ignition plugs sustain heavy damage and have Ignition plugs sustain heavy damage and have reduced life.reduced life.The Arc is a big source of ElectroThe Arc is a big source of Electro--Magnetic noise that Magnetic noise that will drown out signals from transducers.will drown out signals from transducers.

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•Motor driven. (Motor is source of EMI and vibrations.)

•Belts slip and valves lose synchronicity.

•Need a sensor (magnetic pick up or optical transducer) to sense valve position.

•Very difficult to time ignition.

•Rotary valves leak and higher pressures are not possible.

•Therefore, stoichiometric mix or proper equivalence ratio not possible.

•Higher frequency not possible.

20032003--20042004

Propane + Oxygen

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20042004--20052005

• Blockage Ratio of 50 to 55% most effective for DDT.

• Without water cooling, tube deforms, pre-ignition.

• Run time 10 seconds to 1 minute.

• Spirals break up in high pressure + temperature environment.

• Propane + Oxygen

• Rotary Valve

•

Automotive Ignition with Tungsten rod spark plugs

•

Tested various Shchelkin spiral lengths, pitch, blockage ratio.

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LateLate 20052005

Propane + Oxygen

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2006: Application of PDE for Electric Power Generation 2006: Application of PDE for Electric Power Generation

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Objectives of the New PDE DesignObjectives of the New PDE DesignBuild a PDE platform to perform various structured Build a PDE platform to perform various structured studiesstudiesGaseous and Liquid Fuels, variable equivalence ratio, fill Gaseous and Liquid Fuels, variable equivalence ratio, fill rates, etc.rates, etc.Long Duration Run Times (30 min. to 1 hour)Long Duration Run Times (30 min. to 1 hour)High cycle frequency (0 to 100 Hz)High cycle frequency (0 to 100 Hz)Modular design, configurable easily for different test Modular design, configurable easily for different test casescasesLow energy ignitionLow energy ignitionElectrical solenoid valve injectionElectrical solenoid valve injectionFully controllable via computer and monitor in real timeFully controllable via computer and monitor in real time

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Compact Liquid Fueled PDE with PreCompact Liquid Fueled PDE with Pre--detonatordetonator

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PrePre--detonatordetonatorFuelFuel--Air mixtures have high DDT run up distance Air mixtures have high DDT run up distance and initiation energy. Preand initiation energy. Pre--detonator can shorten detonator can shorten the run up distance and provide the energy the run up distance and provide the energy required to drive the pressure wave to required to drive the pressure wave to detonation.detonation.Thus, a low energy ignition source is sufficient.Thus, a low energy ignition source is sufficient.If spirals and DDT enhancing obstacles can be If spirals and DDT enhancing obstacles can be avoided, thrust is not lost due to drag.avoided, thrust is not lost due to drag.

Small quantities of highly detonable mixtures are Small quantities of highly detonable mixtures are used to generate DDT within the main used to generate DDT within the main combustor.combustor.Smaller sized preSmaller sized pre--detonators require less Odetonators require less O22and fuel, as opposed to preand fuel, as opposed to pre--detonator and main detonator and main combustor having same area of crosscombustor having same area of cross--section.section.In hybrid PDEIn hybrid PDE--CompressorCompressor--Turbine engines, the Turbine engines, the prepre--detonator can get the engine started from detonator can get the engine started from full stop. Once the engine builds up speed, the full stop. Once the engine builds up speed, the prepre--detonator may be cut off.detonator may be cut off.

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Why Propane?Why Propane?Propane is friendlyPropane is friendly‘‘coz we are from Texas, coz we are from Texas, yaya’’allallAlready tested in prior studies, Already tested in prior studies, plenty of data availableplenty of data availableMajor component of Natural gasMajor component of Natural gasEasy availability of propane in Easy availability of propane in various containers. Viable as a various containers. Viable as a fuel for commercial hybrid PDEsfuel for commercial hybrid PDEsCell sizes very similar to many Cell sizes very similar to many liquid fuels, such as JPliquid fuels, such as JP--10, with 10, with air.air.

www.usepropane.comCopyright ©

2005 by the Propane Education & Research Council.

www.propane-generators.com/

www.buckandryan.co.uk

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Propane + OxygenPropane + OxygenLow energy ignitionLow energy ignitionRedundant spark plugRedundant spark plugTangential gas injectionTangential gas injectionFlanged Shchelkin spiralFlanged Shchelkin spiralCan be run as a stand alone Can be run as a stand alone detonation tube, with the addition of detonation tube, with the addition of an existing combustion chamber with an existing combustion chamber with pressure transducer portspressure transducer ports

PrePre--detonator (contd.)detonator (contd.)

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dc = 13λ for area abrupt area changedc = 26λ for D/DCJ →1.3 over-driven detonations1

dc = 8.3 mm for propane/oxygen mixture2

DDT was achieved in distances ranging from 5 to 25 cm for 1 in. diameter tube using propane-oxygen mixtures with varying equivalence ratio (1.6 to 0.85)3

1 in. i.d. (1 in. i.d. (25.4 mm/1.7 mm≈15), length = 10 in.

PrePre--detonator (contd. 2)detonator (contd. 2)

[1] Desbordes, D., Lannoy, A., “Effects of a Negative Step of Fuel Concentration on Critical Diameter of Diffraction of a Detonation,”

Progress in Astronautics and Aeronautics, Vol. 133, 1991, pp. 170-186.[2] Schultz, E., “Detonation Diffraction through an abrupt area expansion,”

PHD Thesis, California Institute of Technology,2000.[3] Li, J., Lai, W.H., Chung, K., “Tube Diameter Effect on Deflagration to Detonation Transition of

Propane-OxygenMixtures”, Shock Waves, Vol. 16, No. 2, December 2006, pp. 109-117.

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Main CombustorMain Combustor

Designed to be a stand alone detonation tube Designed to be a stand alone detonation tube with the addition of an igniterwith the addition of an igniterThe end flange allows extension of length or The end flange allows extension of length or addition of other devices, e.g. a turbine.addition of other devices, e.g. a turbine.

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Main Combustor Inlet Block (contd.)Main Combustor Inlet Block (contd.)

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Solenoid Valves and Electronic Fuel Solenoid Valves and Electronic Fuel Injectors (1)Injectors (1)

Solenoid ValvesSolenoid Valves••12 Vdc, 8A peak, 2A hold.12 Vdc, 8A peak, 2A hold.••Fast acting (2ms reaction time). Up to 35Hz tested Fast acting (2ms reaction time). Up to 35Hz tested successfully. 50Hz max.successfully. 50Hz max.••Easy and precise control possible using TTL Easy and precise control possible using TTL signals from a remote computer.signals from a remote computer.••Max pressure 550 kPa (90psig)Max pressure 550 kPa (90psig)

AFS-Gs60-05-5c series Fuel Valves

Alternate Fuel Systems (2004) Inc. Calgary, Canada

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Solenoid Valves and Electronic Fuel Injectors (2)Solenoid Valves and Electronic Fuel Injectors (2)

Gasoline Direct Injectors

Pressure rating of 14 MPa

(2000 psi)

Particle size of about 50 μm. DENSO CORPORATION Japan

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Denso Driver CircuitDenso Driver Circuit

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Denso Injector Water TestDenso Injector Water TestWater at 10 MPa.

Measurement of Sauter’s

Mean Diameter (SMD) usingMalvern Insitec Ensemble Particle Concentration and Size (EPCS) meter

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Digital (TTL) Control of Valves and Ignition:Digital (TTL) Control of Valves and Ignition: Control Duty Cycle and FrequencyControl Duty Cycle and Frequency

Vol

ts

Time (s)

Vol

tsV

olts

Purge AirValveCycle

Fuel, OxygenValvesCycle

IgnitionControlCycle

50%

40%

5%

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Liquid FuelLiquid Fuel--Air Mixing ChamberAir Mixing Chamber

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Liquid FuelLiquid Fuel--Air Mixing Chamber (contd.)Air Mixing Chamber (contd.)

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Liquid Fuel PumpLiquid Fuel Pump

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150 mJ max energy per spark Inductive Ignition System

A transistor control circuit built in house enables the interfacing of the ignition system to the DAQ PC and allows ignition to be controlled remotely.

Ignition System

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Schematic of the complete PDESchematic of the complete PDE

DiagnosticsDiagnostics. Dynamic pressure transducers (PCB 111A24 model, 1000 psi maximum, 450 kHz resonant frequency) with water cooling adapters (064A01 recessed sensor and 064B02 flush sensor models)•Load cells: piezo-electric PCB 201B03 (500 lbf) and201B05 (5000 lbf)

•Photo-diode based optical sensors

•National Instruments DAQ consisting of a 1042Q chassis with two 8 channel 2.5 MS/s S-series PXI-6133 cards. •The DAQ is connected to a remote PC via fiber optic cable which ensures smooth, EMI free signal transmission. •PXI-6624 8 channel counter installed in the DAQ chassis that provides 8 configurable counters, enabling up to 8 devices to be precisely timed using the DAQ. •LabVIEW is used to build all user interfaces.

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Optical SensorOptical SensorHamamatsu photodiodes part number 1226-18BU), 1.1 mm square window sensitive to light between 190 and 1000 nm wavelengths

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New PDE smellNew PDE smell

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Test ProgramTest ProgramTest frequency is set: 0 to 100 HzTest frequency is set: 0 to 100 HzPropane and Oxygen are injected simultaneously: Propane and Oxygen are injected simultaneously: varying equivalence ratio, fill volumevarying equivalence ratio, fill volumeLiquid fuel is mixed with air and injected: varying Liquid fuel is mixed with air and injected: varying equivalence ratio, fill volumeequivalence ratio, fill volumeIgnition spark is fired, blow downIgnition spark is fired, blow downFollowed by purgeFollowed by purgeDiagnostics can only be done for short periods, as long Diagnostics can only be done for short periods, as long duration tests can damage sensors.duration tests can damage sensors.Longer duration tests > 2 minutes, will be done with no Longer duration tests > 2 minutes, will be done with no PTs and only externally located sensors.PTs and only externally located sensors.Liquid Fuels: Jet A, Kerosene, JPLiquid Fuels: Jet A, Kerosene, JP--10, JP10, JP--4,etc.4,etc.Also: propaneAlso: propane--oxygen+ propaneoxygen+ propane--airair

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Future StudiesFuture StudiesPDE with liquid fuel + air testPDE with liquid fuel + air test1 minute to 30 minute duration1 minute to 30 minute durationEffect of interface location and area Effect of interface location and area change on detonation wavechange on detonation wave

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ConclusionConclusionA PDE platform capable of using liquid fuel with air, A PDE platform capable of using liquid fuel with air, using a preusing a pre--detonator has been built. detonator has been built. Cycle frequency, Equivalence ratios and Fill Rates can Cycle frequency, Equivalence ratios and Fill Rates can be controlled via solenoid valve timing and control of be controlled via solenoid valve timing and control of feed line pressure.feed line pressure.Has integrated water cooling, expecting Long Duration Has integrated water cooling, expecting Long Duration Run Times (30 min. to 1 hour)Run Times (30 min. to 1 hour)High cycle frequency possible (0 to 100 Hz)High cycle frequency possible (0 to 100 Hz)Modular design, configurable easily for different test Modular design, configurable easily for different test cases, addition of tube extensions, turbine, etc.cases, addition of tube extensions, turbine, etc.Low energy ignitionLow energy ignitionCan be fully controlled and monitored in real time via Can be fully controlled and monitored in real time via computer.computer.