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BULLET/NC-based Propellant

Management and Elimination ofWorkshop Held

Ozone-Depleting Substances

Continuing rheological and physi-cal property problems encounteredin the extrusion of nitrocellulose(NC)-based propellants have led toa broadly based effort to examinethe causative factors involved . Theissues are being addressed by theJANNAF Propellant Developmentand Characterization Subcommittee(PDCS) by sponsoring technicalworkshops dealing with the manufac-ture, processing, and characterizationof NC and NC-based propellants,and the materials used in theirproduction .

The most recent workshop washeld on 15-16 August 1989 at theVirginia Polytechnic Institute andState University (VPI), Blacksburg,Virginia, with G. W. Nauflett, NavalSurface Warfare Center (NSWC),and J. D. Rancourt, VPI, serving ascochairmen . Thirty-eight NC spe-cialists participated in the discus-sions.

Extrusion-related material vari-ables that were discussed include NCmolecular weight distribution, degreeof nitration, fiber length and orienta-tion, and nitrate substitution pattern.Also discussed were the factors af-fecting stability and aging of NC-based propellants, and ingredientanalysis and characterization usingvarious analytical methods includingnuclear magnetic resonance, chroma-tography, and thermal analysis .A summary of the proceedings,

consisting of abstracts and slides, willbe published by CPIA. For furtherinformation, contact Leland B. Piper(CPIA) at (301) 992-7307 .

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Vol. 15, No. 6, October 1989

As part of the U.S . effort toimplement the Montreal Protocol onSubstances that Deplete the OzoneLayer, conservation and controls onthe use of certain chemicals will berequired . These include the chloro-fluorocarbons CFC-11, CFC-12,CFC-113, CFC-114, and CFC-115, aswell as Halon 1211, Halon 1301, andHalon 2402 . The EPA has proposedthe addition of carbon tetrachlorideand methyl chloroform .

The Montreal Protocol is subjectto periodic review, and other chemi-cals may be added to the list . CFCsand Halons are approved by DoDfor fire protection and as solvents/cleaning agents and refrigerants .The DoD issued directive number6050.9 dated 13 February 1989,which establishes policy in five areasimpacted by the Montreal Protocol .These are: management of theinventory of CFCs and Halons ;identification of CFC and Halonapplications and prioritization oftheir use; a tracking system to docu-ment annual requirements ; the lonb

PDCS Meeting To Be Held AtJHU/APL

The 20th JANNAF PropellantDevelopment and CharacterizationSubcommittee (PDCS) Meeting willbe held on 28 Nov-1 Dec 1989 atthe Johns Hopkins University/Applied Physics Laboratory inLaurel, Maryland . Mr. Irwin D.Smith of the NASA Johnson Space-

term process of decreasing DoDdependence on CFCs and Halonsdue to reduced availability and pro-duction limits ; and research anddevelopment programs to develop orevaluate suitable substances for thesechemicals in mission-critical applica-tions.

The general plan is to adoptsuitable substitute chemicals as soonas practical and to develop, andimplement as necessary, new equip-ment and systems that do not useozone-depleting substances . Untilthen, conservation and stockpiling ofadequate reserves are necessary .Implementation of the requirementto reduce and eliminate use of thecontrolled chemicals will also impactsuch functions as procurement, test-ing, training, hazardous waste man-agement, reporting of air emissions,and preparation of specifications .Further information may be obtainedby contacting Dr. Mae Fauth,NSWC, at (301) 743-4857 or AV364-4857.

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craft Center/White Sands TestFacility, the incoming PDCS chair-man, will serve as the meeting chair-man. The overall security classifica-tion of this meeting is Unclassified,but attendance is limited to invitedU.S . citizens .continued on page 2

Recent CPIA Publications PropellantIngredients UpdateReport #2CPA/1989, Interim Issue A, Chemi-

cal Propulsion Abstracts, Sep 1989 .

CPIA/MI, "Rocket Motor Manual(U)," Units 598 (M120 RocketMotor, R. S. Hellfire), 599 (AQM-127A, SLAT), and 600 (AGM-65,Reduced Smoke Maverick), Aug1989 .

CPTR 89-45, "Disposal of SolidRocket Motor Propellants," Jul 1989 .

CPIA Pub. 509, "1989 JANNAFPropulsion Systems Hazards Subcom-mittee Meeting (U)," Vols . I-II, Feb1989 .

CPIA Pub. 511, "Application of CTto the Minuteman Missile System,"NDES Workshop, Mar 1989 .

CPIA Pub. 517, "2nd Navy Indepen-dent Research/Independent Explora-

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Symposium _Wy"Vols . I-II, Jun 1989 .

IS89-01: Electrostatic Propulsion(Partially supersedes LS86-30) ;period covered 1969-1988C; 84citations and abstracts.

IS89-05: Rocket Nozzle Instrumen-tation (Supersedes LS85-O1) ; periodcovered 1969-1988C; 86 citations andabstracts.

PDCS Meetingcontinued from page 1

Forty-two papers and eight panelbusiness meetings are scheduled forthis four-day meeting. Technicalpapers will address liquid propellantcharacterization, solid propellantingredient analysis, solid propellantchemical test methods, propellantdevelopment and processing, particle

IS89-06: Automated Processing ofSolid Propellants (Supersedes LS86-03) ; period covered 1958-1988D ; 59citations and abstracts .

LS89-07: Exhaust Plume FlowFields -- Theoretical and Computa-tional Studies; period covered 1969-198813 ; 318 citations.

LS89-08: Exhaust Plume FlowFields -- Experimental Studies; peri-od covered 1969-198813; 179 cita-tions .

LS89-09: Carbon-Composite Materi-als Properties (Partially supersedesLS86-09) ; period covered 1969-1988D; 92 citations and abstracts .

LS89-10: Rocket Exhaust PlumeRadar Cross-Section (SupersedesLS83-19) ; period covered 1969-1988Cr-7-S-citations and abstracts .

LS89-11: Liquid Propellant GunTechnology (Supersedes LS77-05,LS82-25, and LS82-26) ; periodcovered 1954-198813; 382 citations.

LS89-13: Caseless, Combustible,and/or Consumable Cartridges (U)(Supersedes LS82-02) ; periodcovered 1947-19888 ; 191 citationsand abstracts .

size analysis, rheology, and propel-lant surveillance . The scheduledpanel meetings encompass rheology,propellant surveillance, the PDCSHandbook, liquid propellants, solidpropellant ingredients, micromeritics,propellant development and process-continued on page 5

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The following is a brief listing ofrecent developments in the area ofrocket and gun propellant ingre-dients availability:

The Olin Corporation recently in-creased the price for its toluenediisocyanate (TDI) curative by 8cents per pound, to approximately$1.25 per pound. Air Products andChemicals reportedly has also begunmanufacturing TDI for the plasticsindustry.

e Recent research has shown thatm-tetramethylxylene diisocyanate(TMXDI) may be a suitable replace-ment material for isophorone diiso-cyanate (IPDI) due to its reducedtoxicity, similar price, and similarchemical reactivity . This isocyanateis manufactured by American Cyana-mid at its Willow Island, West Vir-ginia plant.

NASA is pursuing developmentof a second source for rayon-precur-sor carbon fibers, due to continuingfinancial and environmental difficul-ties with the current sole sourcemanufacturer, Avtex Fibers of FrontRoyal, Virginia . Foreign sources,such as Courtaulds and BASF, arealso interested . Rayon-based carbonfibers are used in the manufacture ofthe Shuttle solid rocket motor noz-zle, as well as some military nozzlecomponents. There are a number ofU.S . manufacturers for other typesof carbon fibers based on eitherpitch or polyacrylonitrile (PAN)precursors .

For further information on theseitems, or on the subject of propel-lant ingredients availability, pleasecontact the CPIA (Tracy D. Wilson)at (301) 992-7302, or FAX (301)730-4969.

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1989 JANNAF Propulsion Meeting HighlightsElectric and Advanced PropulsionDevelopments

A number of sessions at therecent JANNAF Propulsion Meeting(JPM), held in Cleveland, Ohio inMay, dealt with the status of electricand advanced propulsion conceptstechnology . Electric propulsion sys-tems are planned for upcoming flighttests, such as the SP-100 demonstra-tion mission, and for operationaluse, such as for drag-makeup thrust-ing on the Space Station "Freedom."Advanced propulsion concepts, par-ticularly antiproton, are being ex-plored as high-risk but potentiallyhigh-payoff means of breaking freefrom the performance constraints ofchemical and electric propulsionsystems .

In the electric propulsion area,principal emphasis at the JPM wasplaced on the NASA efforts on lowpower, hydrazine arcjet thrusterdesign optimization, including charac-terization of cathode erosion mecha-nisms, nozzle design impacts onperformance, and the developmentand testing of an engineering modelarcjet . Experiments at NASA'sLewis Research Center showed thatthoriated tungsten cathodes and theuse of conical nozzle designs yieldoptimum arcjet performance.

Qualification testing of an en-gineering model 1 kW arcjet at theRocket Research Corporation de-monstrated its flight worthiness forgeosynchronous satellite north-south,station-keeping propulsion missions .Information was also presented onthe development of an arcjet upperstage to be used with the new Pega-sus launch vehicle. This electricpropulsion upper stage will allowtransfer of small satellite payloads,900 pounds or less, to higher, work-ing orbits, including geosynchronousequatorial orbit.

Other papers in the electric pro-pulsion sessions covered large diame-ter, 50 cm xenon ion, and 130 kWargon and helium magnetoplasma-dynamic thruster testing and designstudies. The status of the Astro-nautics Laboratory-sponsored solarthermal propulsion effort, missionanalyses of various electric propul-sion candidates, and the developmentof improved thruster diagnostic facil-ities were also presented.

Developments in the advancedpropulsion concepts area have cen-tered on the evolving antiprotonpropulsion technology. The Astro-nautics Laboratory, the leadorganization in this Air Force Fore-cast 11 effort, is attempting to forma national consortium of laboratoriesto pursue this high-cost, high-riskarea. A session at the JPM dis-cussed the current status of thisprogram which currently consists oftheoretical and limited experimentalstudies . The complementary ad-vanced propulsion concepts programof NASA, led by the Jet PropulsionLaboratory and the Lewis ResearchCenter, covers fission and fusionpropulsion concepts as well . Bothefforts are also exploring the syn-thesis of very high energy, high den-sity chemical propellant ingredientsas a near-term improvement to thespecific impulse limitations of exist-ing chemical propulsion systems .

Recent CPIA literature searches(LS88-15, 89-01, 89-02) have sum-marized the published results inelectrothermal, electrostatic, andelectromagnetic propulsion, respec-tively . These documents containreferences to over 450 electric pro-pulsion reports and include abstracts,and are available to CPIA sub-scribers by calling (301) 992-7302 . c

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Gun Propulsion

The two main gun propulsiontopics covered at the 1989 JPM wereliquid guns and low vulnerability am-munition (LOVA) propellant devel-opment. Most of the liquid gunresearch in recent years has focusedon the regenerative liquid propellantgun (RLPG), using hydroxylammoni-um nitrate (HAN)-based monopro-pellants . The HAN-based monopro-pellants are preferred over bipropel-lants because they are less toxic andcorrosive.

These monopropellants also offeradvantages over conventional gunpropellants, including cheaper manu-facturing, relatively safe storage dueto the high pressures needed toignite, rapid loading, lower muzzleflash, higher muzzle velocities, high-er loading densities, and improvedlogistics .

One problem this JPM sessionhighlighted is the presence of pres-sure oscillations encountered inRLPGs during the combustion proc-ess. High frequency oscillationshave been encountered in liquid gunchambers that are similar to thosefound in liquid rocket engines. Onemajor difference in RLPGs is thatthey operate at a much higher cham-ber pressure (in the range of 30,000psia) than liquid rocket engines(usually not above 3,000 psia) .These pressure oscillations can causehigh pressure spikes, increased heattransfer, and mechanical vibrationswhich can result in increased erosionand/or corrosion problems. Thiscould result in premature failure ofthe gun components .

The high frequency oscillationsthat are occurring in the gun com-bustion chamber appear to be acous-tically related, so liquid rocket en-gine stability principles are beingapplied . Some of the areas that are

currently being investigated includethe injector and injection effect onthe combustion process and thecoupling of the injection and com-bustion processes . Modeling ofthese processes and their influenceon the high frequency oscillationsare also being explored .

The session on insensitive muni-tions for guns covered developmentof replacement propellants for conventional guns . Conventional gunsand weapon systems use double- andtriple-based propellants which havebeen shown to be sensitive to hotfragment ignition and sympatheticdetonation . Much effort is beingspent to replace these materials withLOVA propellants that are lessvulnerable but retain the same per-formance characteristics of conven-tional propellants.

The propellants being developedfor this purpose are usually thenitramine-containing propellants withhigh energy plasticizers and bindersto improve the ballistic performance.Generally, nitramines are resistant toignition and have a low-burn rate atlow pressures, which produce ir-regular ballistic performances . ThisJPM session indicated that the pres-ent research focuses on developmentof additives or new energetic bindersthat improve the ballistic perfor-mancewithout increasing the propel-lant sensitivity.

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AirbreathingPropulsion

Airbreathing propulsion was wellcovered at this year's JPM withseven main sessions that includedperformance analysis, liquid fuelramjets, solid fuel ramjets, combinedcycle engines, hypersonic propulsion,tactical turbine engines, and ductedrockets.

JPM Highlights (Continued)The session on airbreathing

performance analysis included mis-sion studies for the solid fuel ramjet(SFRJ), a comparison of ramjets andturbojets for tactical applications andthe applicability of the airturbo-ram-jet (ATR) to air-launched missions.Some main conclusions were thatthe SFRJ using advanced fuelscontaining boron as an ingredientcan offer a 50-100% range gain oversolid motors, ATRs may be attrac-tive for very-long-range tacticalmissions, and supersonic turbojetscan offer significant weight savingsover ramjets for selected missions .

The liquid fuel ramjet (LFRJ)session began with a historical per-spective of ramjet technology devel-opment from the `flying stovepipe'normal-shock inlet engine to thehydrogen-fueled supersonic combus-tion ramjet engines being developedunder the National Aerospace PlaneProgram. The author detected a 20-year cycle in ramjet technologydevelopment - a dual-mode, hydro-gen-fueled supersonic combustionramjet was a dynamic innovation in1967. The LFRJ has become amature technology as evidenced bypapers presenting optimization tech-niques for inlet selection and fuelinjection systems. The session endedwith an excellent in-depth review ofan Office of Naval Research/NAV-AIR research program on combus-tion instability in ramjets . Theprogram spanned 5 years and in-volved 11 organizations. Substantialprogress has been made in under-standing the causes of ramjet com-bustion instability and in the applica-tion of computational fluid dynamicsto flow in a dump combustor.

The solid fuel ramjet (SFRJ)session began with an overview of aprogram to develop an SFRJ for anadvanced, high-speed, air-to-groundmissile. The successful completionof this program shows that the SFRJ

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offers a simple, low-cost, high-perfor-mance propulsion system for anumber of missile applications .Both the Atlantic Research Corpora-tion and United Technologies Cor-poration/Chemical Systems Divisionshowed that castable boron fuels forSFRJs are practical. Boron has thehighest heating value of any of themetal additives, but early workshowed significant problems both inprocessing andcombustion efficiency.These problems have recently beenovercome with proprietary boronsurface treatment procedures and theuse of combustion catalysts to in-crease efficiency. SFRJs with boronfuels are now very competitive formany missile applications . Thesession ended with the description ofan interesting technique for control-ling SFRJ thrust by controlling inletair flow .

Combined cycle engines, such asthe airturbo-rocket or airturbo-ram-jet, are seeing increased emphasisbecause they are capable of operat-ing over a broad flight regime (Mach0 to Mach 6) . In the airturbo-rocket, a fuel-rich gas generator isused to drive an air intake compres-sor. The air and fuel-rich gases arethen burned in a ramjet combustionchamber. In the airturbo-ramjet, theturbojet and ramjet are integrated inthe same engine and air intake isdiverted from the turbojet to theramjet at higher Mach numbers.This year's combined cycle enginesession emphasized the latter tech-nology with papers on turbo-ramjetmission analysis for manned andunmanned vehicles, componentdevelopment, and fuels evaluation.It was evident that airframe andpropulsion integration is an extreme-ly important factor for these complexengines.

The session on hypersonic pro-pulsion and test techniques beganwith an excellent overview of current

JPM Highlights(Continued)

and planned test facilities . Lack offacilities for the higher Mach num-ber regimes can affect the risk andcost of hypersonic propulsion devel-opment programs . The session alsoincluded several papers on theexperimental and numerical inves-tigation of scramjet flows in thecombustor and nozzle. Also note-worthy were combustor test resultson a hydrogen-fueled scramjet atMach 8 conditions .

Achieving low costs with accept-able performance was the dominanttheme of the tactical turbine enginesession. With tactical missiles, themain objective is to field as manyweapons as possible to meet numeri-cally superior threats, so cost is amain driver. Approaches to lower-ing cost include automation, relaxedtolerances, modular construction,component commonality, and fewerinspection and documentation re-quirements . The increasing impor-tance of tactical turbojets was shownin a paper by Teledyne which de-scribed the development of turbojetscovering the 40-350 lbf thrust range- all with internal funding.A highlight of the ducted rocket

and integral rocket/ramjet compo-nent session was an overview of thevariable-flow, ducted rocket advanceddevelopment program. This is a5-year ground test program whichwill culminate with a full-scalefreejet engine demonstration . Vari-able fuel control significantly im-proves the performance and ver-satility of the ducted rocket . Otherpresentations included a compositetactical inlet demonstration andimproved ramjet insulators andbonding systems.

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PDCS Meetingcontinued from page 2

ing, and solid propellant chemistrytest methods.

Authors of papers are remindedthat the deadline for the receipt ofmanuscripts and paper clearanceforms at CPIA is 10 November 1989.Cleared papers not received by thisdate will be removed from the pro-gram unless special arrangementshave been made with CPIA and themeeting chairman . Meeting atten-dees are also reminded that the

DTIC '89 -ANNUAL USERSCONFERENCE

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deadline for the receipt of personalregistration forms at CPIA is 13November 1989 . Admittance to themeeting may be denied or delayed ifregistration forms are not received intime.

The proceedings of this meetingwill be published and distributed byCPIA to qualified subscribers inFebruary 1990. For further meetinginformation, contact Melissa Paul at(301) 992-7302 .

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The Defense Technical Information Center (DTIC) will hostDTIC '89 -Annual Users Conference from October 30, 1989 toNovember 3,1989 atthe Ramada Hotel-Old Town, 901 North FairfaxStreet, Alexandria, Virginia, (703) 683-6000 . The Conference offersa full week of practical sessions and state-of-the-art information . Thetheme is DTIC - Your Key to Information. The registration fee is$145.00 for registration until October 20, 1989 . Late registration is$170.00. TheAmerican Defense PreparednessAssociation is handlingthe registration . They can be reached on (703) 522-1820 . TheDefense Technical Information Center point of contact isMs. Kay Grigsby, (202) 274-3848 orAutovon 284-3848 . Conferencenotices will be mailed in September.

Attendance At JANNAF Conferences and Workshops is by invitation only.

MEE'T'ING CALENDAR SUBJECT' TO CHANGE. FOR LATEST DETAILS, CONTACT CPIA at (301) 992-7306 .

CP

BulletinCHEMICAL PROPULSIONPROPULSION

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INFORMATION AGENCY

THE JOHNS HOPKINS UNIVERSITY " APPLIED PHYSICS LABORATORYJOHNS HOPKINS ROAD, LAUREL, MARYLAND 20707

ADDRESS CORRECTION REQUESTED

The Bulletin is published bimonthly by the Chem-ical Propulsion Information Agency (CPIA) . CPIAis a DoD Information Analysis Center responsiblefor the acquisition, compilation, analysis, and dis-semination of information and data relevant to chem-ical and electric propulsion technology . In addition,CPIA provides technical and administrative supportto the Joint Army-Navy-NASA-Air Force (JAN-NAF) Interagency Propulsion Committee . The pur-pose of JANNAF is to solve propulsion problems,coordinate technical programs, and promote an ex-change of technical information in the areas of mis-sile, space, and gun propulsion technology . A feecommensurate with CPIA products and services ischarged to subscribers. Also, subscribers must meetsecurity and need-to-know requirements .

The Johns Hopkins UniversityApplied Physics LaboratoryJohns Hopkins RoadLaurel, Maryland 20707-6099(301) 992-7304 or 953-5850Operating under Contract N00039-89-C-0001

Ms . Catherine McDermott

EditorMs . Lorri A. Pickett

Associate EditorMs . Brenda R. Prater

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U.S. POSTAGE

PAIDLAUREL, MARYLANDPERMIT No.1885

NONPROFIT ORGANIZATION

1989 Meeting Type Location Sec. ClassAbstract/Paper

Deadline

6-9 Nov JANNAF Joint Composite Motor Conference/ JPL Unclassified/ Past PastCase Subcommittee/Structures & Workshops Pasadena, CA LimitedMechanical BehaviorSubcommittee Meeting

14-15 Nov Turbojet Specifications Workshop MICOM Unclassified/ N/A N/AHuntsville, AL Limited

14-17 Nov JANNAF Exhaust Plume Technology Conference/ NPS Secret Past PastSubcommittee Meeting Workshops Monterey, CA

28 Nov-1 Dec JANNAF Propellant Development Conference/ JHU/APL Unclassified Past 10 Novand Characterization Workshops Laurel, MDSubcommittee Meeting

1990

2-6 Apr JANNAF Propulsion Systems Conference/ JHU/APL Confidential/ 23 Oct 12 MarHazards Subcommittee Meeting Workshops Laurel, MD Limited

3-5 Apr JANNAF Nondestructive Evaluation Conference/ INEL Unclassified/ 24 Oct 13 MarSubcommittee Meeting Workshops Idaho Falls, ID Limited

16-20 Jun JANNAF Safety & Environmental Conference/ LLNL Unclassified/ 8 Jan 28 MayProtection Subcommittee Meeting Workshops Livermore, CA Limited