000ppt atk thiokol propulsion a collaborative effort for manufacturing and testing of gem rocket...

000ppt

ATK ThiokolPropulsion

A Collaborative Effort for Manufacturing and Testing of GEM Rocket Propellant

A Collaborative Effort for Manufacturing and Testing of GEM Rocket Propellant

Mike Rose, Connie Murphy and Rich Muscato

Presented by:

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ATK Thiokol Propulsion

Outline Program objectives NSWC-IH Accomplishments Process transition Computer modeling Inert processing Live processing Ballistic differences Motor Firings Conclusions

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Program Objectives NSWC-IH

Develop a continuous manufacturing process for TPE based rocket propellant using a twin screw extruder (TSE)

Manufacture TPE based rocket propellant in the 40mm TSE and test Establish baseline ballistic data (strands) based on specific ballistic targets

for burn rate and slope Provide propellant for high pressure motor firings Transfer process technology to ATK Thiokol for scale-up work

ATK Thiokol Scale-up continuous manufacturing process established at NSWC-IH to

58mm TSE Manufacture TPE based rocket propellant in the 58mm and test Compare ballistic data to NSWC-IH baseline targeting burn rate and slope Recover, recycle, re-use (R3) Test high pressure motors using propellant manufactured at NSWC-IH and

ATK Thiokol

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NSWC-IH Accomplishments Developed a continuous manufacturing process for TPE based

rocket propellant using a twin screw extruder (TSE) Characterized raw material feed streams

Flow rates and location Optimized extrusion process parameters for the 40mm TSE

Temperature profile, screw configuration and screw speed

Successfully and safely manufactured TPE based rocket propellant in the 40mm TSE and established ballistic baseline data Specific targets for burn rate and slope

Demonstrated consistent propellant properties from run to run Physical (density) and ballistic (burn rate and slope) properties

Provided propellant for high pressure motor firings Transferred process technology to ATK Thiokol for scale-up to

58mm TSE

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58mm TSE Inert Processing

58mm TSE Inert Processing

Extrusion Protocol for GEM Rocket Propellant

Safety Characterization

of Energetic Materials

Safety Characterization

of Energetic Materials

Rheological Characterization

Performed by NSWC-IH

Rheological Characterization

Performed by NSWC-IH

40mm TSE Parameters Used for Comparison

40mm TSE Parameters Used for Comparison

Technology Transfer from

NSWC-IH

Technology Transfer from

NSWC-IH Rheology

Characterization

Rheology Characterization

Computer Modeling

Computer Modeling

58mm TSE Energetic

Processing

58mm TSE Energetic

Processing

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TSE Computer Modeling Program Developed by the University of Akron

Modeling program uses finite element analysis to predict one-dimensional fluid flow behavior in a TSE

Program inputs Barrel and screw configuration Temperature profile of the extruder barrel Feed stream flow rates and locations Screw speed (rpm) Material properties (physical and rheological)

Program outputs Profiles along the barrel for:

Pressure, temperature, torque, fill factor, and melt Specific energy

Model benefits Quickly assesses relationships and effects of process parameters

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Modeling Effort Objectives for computer modeling

Validate model based on actual extrusion data generated by NSWC-IH for the 40mm TSE

Determine comparable process parameters for the 58mm TSE based on 40mm experience Screw configuration, screw speed, temperature profile and feed

stream flow rates

Modeling results Generated a computer model for the 40mm TSE process that predicted:

Pressure, temperature, fill-factor, and melt profiles along the barrel Specific energy

Used 40mm data (modeled and actual) to establish a similar model for the 58mm TSE

Established initial process parameters for the 58mm TSE

The computer model did not predict any major concerns

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Inert Evaluation

Inert runs were used to identify critical issues regarding the entire process and to solidify processing parameters for live efforts Initial inert run used a substitute for TPE No unusual temperature excursions were experienced during

operation Torque values were higher than expected

Modified screw configuration to reduce power consumption

Post extrusion examination of the initial inert run identified foiling of the aluminum near the feed inlet of the extruder NSWC-IH experienced foiling in the solid feeder

Feed screws were changed solving the problem Cause for the foiling has been attributed to frictional heating

TPE substitute did not coat aluminum quickly enough

Subsequent runs using actual TPE showed no foiling

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Foiling Phenomenon

Foiling on Screw Element

Foiling Buildup in the Barrel


Foiling Removed from the Barrel


Aluminum Flakes in the Material

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Initial Live Extrusion

Initial live extrusion runs on the 58mm TSE provided valuable information Process parameters modified slightly

Screw speed and feed stream flow rates lowered

Identified inherent concerns for the system

Higher than usual humidity caused AP to hang-up in the feed funnel altering the formulation

Provided extrudate for evaluation

Established baseline ballistic properties for 58mm TSE material

Comparison of ballistic properties from extrudate generated from the 40mm and 58mm TSE showed distinct differences in burn rates

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Ballistic Comparison

1

10

100.0 1000.0 10000.0 100000.0

Pressure (psi)

Bu

rn R

ate

(ip

s)

40mm Baseline - IH94000ELGRM8008658mm Initial Run - M214-00-04358mm Second Run - M214-01-003

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Evaluation of Burn Rate Differences Several factors potentially contributed to ballistic differences of

the propellant Raw materials

The same raw materials used in the 40mm TSE Porosity

Pressed densities generally approached the theoretical maximum density (TMD) of the formulation

Re-processed extrudate in batch mixer and measured burn rates Formulation differences

Compositional differences could not be determined due to analysis variability

Detailed feed stream analysis performed to minimize variability Scale-up idiosyncrasies

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Ballistic Comparison

1

10

100.0 1000.0 10000.0 100000.0

Pressure (psi)

Bu

rn R

ate

(ip

s)

40mm Baseline - IH94000ELGRM8008658mm Initial Run - M214-00-04358mm Second Run - M214-01-00358mm Third Run- M214-01-006Re-processed M214-01-006 in Batch Mixer

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Evaluation of Burn Rate Differences Several factors potentially contributed to the ballistic difference

Raw materials The same raw materials used in the 40mm TSE

Porosity Pressed densities generally approached the theoretical maximum

density (TMD) of the formulation Re-processed extrudate in batch mixer and measured burn rates

Formulation differences Compositional differences could not be determined due to

analysis variability Detailed feed stream analysis performed to minimize variability

Scale-up idiosyncrasies

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Feeder Calibration - AP

34.00

36.00

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50.00

52.00

54.00

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Sample Number

Fee

d R

ate

(lb

s/h

r)

Calculated Feedrate (lbs/hr) Target Feedrate (lbs/hr) Statistical Average Feedrate (lbs/hr)

StatisticsStd. Dev. = 1.08Coef. Var. = 0.02

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Feeder Calibration - Al

5.00

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7.00

8.00

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15.00

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Sample Number

Fee

d R

ate

(lb

s/h

r)



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ATK Thiokol PropulsionFeeder Calibration – TPEInitial ParametersBAMO-AMMO Calibration Plot

Test 1

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23.00

25.00

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Sample Number

Fee

dra

te (

lbs/

hr)



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ATK Thiokol PropulsionFeeder Data – TPEAdjusted ParametersBAMO-AMMO Calibration Plot

Test 3

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7.00

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11.00

13.00

15.00

17.00

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21.00

23.00

25.00

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Sample Number

Fee

dra

te (

lbs/

hr)



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ATK Thiokol PropulsionBallistic Comparison

1

10

100.0 1000.0 10000.0 100000.0

Pressure (psi)

Bu

rn R

ate

(ip

s)

40mm Baseline - IH94000ELGRM8008658mm Initial Run - M214-00-04358mm Second Run - M214-01-00358mm Third Run- M214-01-006Re-processed M214-01-006 in Batch Mixer58mm Fourth Run - M214-01-007

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Process Scale-up Conclusions Minor material differences (ballistic properties) indicate subtle

scale factors exist for the 40mm and 58mm TSE’s Shear environment Heat transfer Process section differences

Modular barrel vs. monolithic barrel Exact feed port location

Confident that with additional work material properties could be duplicated

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High Pressure Motor Firing

Time (sec)

Pre

ss

ure

(p

sia

)

Predicted Performance

Measured Data

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Final Program Conclusions NSWC-IH successfully transferred process technology to ATK

Thiokol Two different extruders, size and configuration, can produce similar

material Modeling played a key role towards reducing experimental iterations Inert runs provide invaluable process information but should be

interpreted carefully

Other program objectives are nearing completion Results suggest that successful scale-up can be accomplished

000ppt atk thiokol propulsion a collaborative effort for manufacturing and testing of gem rocket...

Documents

tse slide

atk thiokol slide

tse parameters

tse computer modeling

ppt atk thiokol propulsion

tse temperature profile

nswcih baseline

tse energetic processing