System Level Overview of the Hypergolic Gelled Propellant ...GPL Overview 2 Oxidizer workstation...
Transcript of System Level Overview of the Hypergolic Gelled Propellant ...GPL Overview 2 Oxidizer workstation...
System Level Overview of the Hypergolic Gelled
Propellant Lab (GPL)
Purdue University
Maurice J. Zucrow Laboratories
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Dr. Timothée L. Pourpoint
Dr. Steve Heister
Dr. William Anderson
Dr. Robert Lucht
Dr. Steven Son
GPL Overview
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Oxidizer workstation
Fuel workstation
General use fume hood
Data acquisition system
Ventilation system
Workbenches
Test stand
LASER
• Dedicated laboratory space for NTO-based and hydrazine-based propellant studies
• Dedicated ventilation system (0.02" H2O P between laboratory and control room)
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Capillary Rheometer
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Droplet Burning/Vaporization
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• Gelled MMH Droplet Combustion
• Objective:
• Improve fundamental understanding of the burning behavior of gelled
MMH droplets
• System Capabilities
• Variable chamber conditions
• Inert or oxidizing environment
• Max pressure: ~10 atm
• Max temperature: ~450 K
• Optical access from multiple angles
Droplet Burning/Vaporization
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1) MMH evaporates from the
droplet surface during
combustion
2) A semi-rigid shell of HPC is
formed
3) The HPC layer blocks diffusion
of the fuel vapor
4) A bubble of MMH vapor is
formed under the HPC layer
(Fig 1-3 )
5) The pressure of the bubble
ruptures the outer layer (Fig 4)
6) A jet of MMH vapor is expelled
from the ruptured area (Fig 4-6)
t = 0ms t = 32ms t = 34ms
t = 35ms t = 38ms t = 39ms
1) 2) 3)
6) 5) 4)
• Results:
Droplet is approximately 2 mm in diameter
MMH Droplet Combustion in a N2O4 Environment
Droplet Burning/Vaporization
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• Droplets of MMH with 3 wt.% HPC show
dependency between mass burning rate and
droplet surface area.
• Disturbances to the combustion process
caused by accumulation of the solid HPC
layer diminish during the combustion
process.
• Droplets with a liquid layer exhibit the
opposite behavior with increasing
disturbances as combustion progresses.
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0.5
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1.5
0 0.2 0.4 0.6 0.8 1R
ed
uced
Vo
lum
e V
/Vi
Reduced Time t/tb
MMH with 3% HPC
MMH with 3%
Tetraglyme
R² = 0.9122
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2 4 6 8 10 12
Mass
bu
rn
ing
rate
m
g /
s
Di2 mm2
Droplet Burning/Vaporization
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• High Repetition Rate Laser Diagnostics
• Objective
• Obtain insight into dynamics of MMH droplet combustion, flame
structure and provide data needed for chemical kinetics modeling
• System Capabilities
• Variable chamber conditions
• Planar Laser Induced
Fluorescence (PLIF) imaging at
up to 5 kHz to observe short
duration combustion phenomena
• Tunable laser wavelength to
excite the OH radical
• High frequency 3-D imaging with
rotating mirror
Droplet Burning/Vaporization
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2mm
2mm
Pc = 103.4 kPa Pc = 413.7 kPa
Impingement point
2mm
• Results
• OH PLIF images of liquid MMH
droplets burning in air
• OH PLIF images of impinging jet
test of H2O2 – Tetraglyme/NaBH4
Droplet Burning/Vaporization
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• Hypergolic Droplet Contact Experiment
• Objective
• Explore fundamental combustion phenomena for contacting hypergolic
propellant droplets in a controlled environment
• System Capabilities
• Controlled environment
– Pressure
– Temperature
– Ambient gas composition and velocity
• Impact velocities
– Up to 10 m/s
• Optically accessible
– PLIF, thin filament pyrometry, absorption spectroscopy, etc.
Droplet Burning/Vaporization
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• Results
• Quantified pre-ignition explosion due
to rapid gas production with
MMH/RFNA
• Examined less toxic hypergolic
propellants
• DMAZ, TMEDA, TMEDA/DMAZ,
BMIMDCA, etc.
• Future Research
• Explore pre-ignition explosion at
higher impact velocities
• Shift toward less toxic hypergolic
propellants
MMH contacting RFNA
• Rheological Characterization of non-Newtonian Propellants
• Objective
• Investigate and quantify non-Newtonian fluid behavior at conditions
experienced by propellants during all stages of operation from low shear
storage up to high shear injection
Non-Newtonian Propellant Characterization
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• System Capabilities
• Low-intermediate shear rotational rheology
• Propellant yield stress, storage/loss
modulus, etc.
• High shear capillary rheology
• Safe testing of toxic propellants
• Controllable shear rate up to 106 1/s
• Remote operation at driving pressures
up to 3000 psia
Non-Newtonian Propellant Characterization
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Fuel Side of
Rheometer Cabinet Loading
Tube
Linear
Encoder
Piston
Rod
Waste
Collection Water Flush
Tank
Capillary Assembly
Capillary
Tube Pressure
Transducers
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Dashed lines represent viscosities
of liquid MMH and RP-1
Non-Newtonian Propellant Characterization
• Results are very similar for MMH and RP-1 gel
• Silica properties dominate rheological behavior
• Viscosity of the gel at high shear is much higher than that of the base fluid
• Direct impact on modeling efforts for gelled propellants
• Results
Spray Ignition/Combustion
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• Hypergolic Propellant Spray Ignition/Combustion
• Objective:
• Characterize and gain an understanding of the ignition and combustion
characteristics of hypergolic propellant sprays
• System Capabilities
• 60°Included Angle
• 360°Optically Accessible Chamber
• Variable chamber pressure and temperature
• Variable O/F, Rm, injection duration
• Highly repeatable injection conditions
• ~3 ms to steady state injection
• Pulsed operation
Spray Ignition/Combustion
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• Results:
• MMH/RFNA
• Less Toxic Hypergolic Propellants
• H2O2 – Triglyme/NaBH4
Pulse 1 Pulse 2 Pulsed Actuator Response
5 mm
5 mm 5 mm