UL L E TIN Vol. 17, No . 4, June 1991

CPIA's New Address S&EPS to Meet at Kennedy Space Cente r

The Johns Hopkins UniversityAttn: (CPIA Staff Member )10630 Little Patuxent Parkway ,Suite 202Columbia, MD 21044-3200

For Classified mail, please address i tas "Attn: Scty Ofc - CPIA". Pleasedirect any questions to CPIA at (301 )992-7300.

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1991 PSHS MeetingHeld at Sandia

The 1991 JANNAF Propulsio nSystems Hazards Subcommittee(PSHS) Meeting was held on 18-22March at the Sandia National Labo-ratories, Albuquerque, New Mexico .Dr. Claude E . Merrill of the PhillipsLaboratory, Edwards AFB, Califor-nia, served as chairman of the meet-ing, which was attended by 227 pro-pulsion system safety scientists andengineers .

The meeting included 58 paper spresented in nine technical sessionscovering insensitive munitions (IM)technology, electrostatic discharge(ESD) hazards, projectile, bullet, andfragment impact hazards, deflagra-tion-to-detonation (DDT) and shock-to-detonation (SDT) phenomena,cookoff hazards, hazards assessmen tand sensitivity testing, and operation -al hazards in propulsion system test-ing. A two-day workshop on IMtesting and several panel meetingswere also held in conjunction withthe annual meeting.continued on page 2

The JANNAF Safety & Environ-mental Protection Subcommittee(S&EPS) will hold its annual meetingon 22-25 July 1991 at NASA/KennedySpace Center, Florida . The meetingchairman is Ms. Pamela G. Clementsof the Navy Ordnance Environmenta lSupport Office, Indian Head, Mary-land .

The meeting will include technica lsessions on environmental protection ;safety technology; atmospheric haz-ards and modeling; instrumentation ;industrial hygiene; reclamation, dis-posal, and demilitarization ; and haz-ardous waste control . The environ-mental protection session will includea summary of the 26 March 199 1S&EPS workshop on alternatives tochlorinated solvents . In addition tothe technical sessions, there will be aspecial keynote session on application

of total quality management princi-ples to safety and environmenta lprotection initiatives in the aerospac eand ordnance industries . A work -shop on solid rocket motor manufac-turing safety will be held on the after -noon of 22 July . Panel meetings wil lbe held on 23 and 24 July 1991 .

The security level of the meetin gis unclassified . Attendance is limitedto U.S. citizens and authorized immi-grant aliens who possess a need-to-know in the area of safety and envi-ronmental problems associated wit hchemical rocket or gun propulsion .

The preliminary program, whic hincluded registration information, wa sdistributed in May. To obtain theprogram materials, or for furthe rinformation, contact Ms . CamilleHudson (CPIA) at (301) 992-7306 . 0

The Sandia National Laboratories, site of the PSHS Meeting .

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1991 PSHS Meeting Recent CPIA Publicationscontinued from page 1

Topics covered in the ESD ses-sions included ESD-induced ignition ;effects of humidity and formulatio non ESD properties; ESD safety inpropellant processing and rocketmotor handling operations; and elec-trochemical effects in solid propel-lants .

The DDT session featured paperson application of the Naval WeaponsCenter (NWC) DDT code to studydamaged propellant burning an dammonium perchlorate combustion ;effects of strain, temperature, andfracture on the burning rates of gu npropellants ; crack/debond propaga-tion in burning solid rocket motors ;and DDT properties of HMX.

Topics covered in the SDT sessionincluded the effects of damage an dpropellant formulation on shoc ksensitivity ; shock initiation phenome-na; and subscale testing and analysismethods to predict results of full -scale IM bullet and fragment impac ttests .

The cookoff session featured pre-sentations on effects of binder typ eand motor case materials on cookoffhazards; evaluation of insulative coat-ing materials for external protection ;correlation of subscale/full-scalecookoff tests; and an overview oftechnology gaps involving cookoffhazards . A tour of the cookoff tes tfacilities at Sandia was also conduct-ed .

The hazards assessment and sensi-tivity testing session included paper son international efforts by The Tech-nical Cooperation Program W Actio nGroup 11 to develop hazard assess-ment protocols for munitions surviv-ability ; a cost/benefit analysis of I Mtechnology ; status of the U .S. Insensi-tive Munitions Information System ; acomputerized expert system proto -

CPIA Pub. 550, "1990 JANNAF Pro -pulsion Meeting," Vols. I-V, Oct1990 .

CPIA Pub. 550, "1990 JANNAF Pro -pulsion Meeting (U)," Vol . VI, Oct1990 .

CPIA Pub . 554, "ESD Countermea-sures," S&EPS Workshop, Oct 1990.

LS91-05 : Particle Size Analysis (su-

type to perform explosive hazardsclassification ; friction sensitivity test-ing; a methodology for selection ofexplosive fill for warhead hardware ;and an overview of ESD Panel activi-ties .

Topics in the test operations haz-ards session covered risk assessmentfor static testing of flawed rocketmotors; facility hardening for possibl emotor detonations; ESD mitigationtechniques in solid rocket moto rhandling ; and some unique aspects o fturbine engine testing .

The impact sensitivity sessions hadpresentations on the response of gunpropellants to shaped charge jet at -tack; measurement and effects o fpropellant damage from projectil eimpact ; effects of motor case materialand projectile geometry on SDT fromprojectile impact ; bullet impact sensi -tivity of rocket motors ; analysis o fstorage configurations of Maverickmissiles to reduce fragment impac teffects on sympathetic detonation ;vulnerability of solid rocket motors t olaser attack; and effects of packaging ,barriers, and propellant formulation

persedes LS86-10) ; period covered1966-1990; 165 citations and ab-stracts .

LS91-08 : Kinetic Energy WeaponsTechnology ; period covered 1960-1991 ; 192 citations and abstracts .

LS91-10: Hybrid Propulsion Tech-nology (supersedes LS88-02) ; periodcovered 1960-1990; 230 citations andabstracts .

on shaped charge jet vulnerability o f25-mm ammunition .

A workshop on IM testing washeld in conjunction with the annualmeeting. This workshop focused o npractical methods and facilities forconducting fragment impact, bulletimpact, shaped charge jet impact ,sympathetic detonation, and fast an dslow cookoff tests .

Several panel meetings were alsoheld during the annual meeting . TheESD Panel met to discuss prepara-tion of a new report covering recen tadvances in ESD technology. TheCookoff Panel convened to discus sresearch needed to develop mecha-nistic understanding and analytical/predictive capability of cookoff reac -tions . The Detonation Mechanism sPanel met to develop recommenda-tions on priorities of technical activi-ties for determining effects of con-finement on sympathetic detonation .

Proceedings of the PSHS Meetingwill be published by CPIA . For or-dering information, contact DorothyBecker (CPIA) at (301) 992-7303 . 0

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Several nonconventional gun tech-nologies are being developed to ei-ther replace or augment conventionalsystems. Conventional solid propel-lant gun system performance is limit-ed by tube length, chamber volume ,gun strength, and the combustioncharacteristics of the propellant . Toimprove muzzle velocity, an increas ein charge and chamber pressure is re-quired, resulting in a significant in -crease in gun size and weight. Innew gun systems, it is desirable to re -duce system vulnerability, improvelogistics, extend gun range, and re -duce costs of propellant and ammuni-tion .

One of these gun systems present-ly receiving significant research an ddevelopment funds and effort is th eliquid propellant gun . Studies sho wthat liquid propellants provide betterperformance, lower cost, and im-proved logistics when compared to

Liquid Gun Systems

solid propellants . However, liquidgun systems are more complex i ndesign than conventional gun systems .

Liquid gun technology in recen tyears has focused on the regenerativeliquid propellant gun (RLPG) . Theliquid propellant gun program hasbeen funded by the Army primarilythrough the Ballistic Research Labo-ratory, Aberdeen, Maryland and th eArmy Armament Research, Develop-ment, and Engineering Center, Pica -tinny Arsenal, New Jersey.

A basic regenerative injection gunconsists of a chamber with a regener-ative piston attached to a convention -al gun tube (Figure 1) . The chamberis divided by the regenerative pisto ninto a propellant reservoir and acombustion chamber. The breechelement through which the pisto nshaft extends defines the length o fthe reservoir. The head of the piston

houses the injection orifices, whic hare initially sealed before ignition .An ignition train completes the gu nsystem. The monopropellant is pre -pressurized in the propellant reser-voir. Hot gas is injected into thecombustion chamber as a result o figniting the primer . This proces spressurizes the combustion chamber ,forcing the regenerative piston to th erear and compressing the liquid pro-pellant in the reservoir; the propel-lant is then injected into the combus-tion chamber. Once the propellan tignites, it burns rapidly and achieve schamber operating pressure . A pres-sure plateau then follows where theincrease of gas in the chamber andflow of gas down the barrel are bal-anced by the combustion of newlyinjected propellant . This phase endswhen the piston completes its stroke .The ballistic cycle is completed by th eexpulsion of the combustion gases .

PROPELLEN TFILL PORT

IGNITIO NPOR T

/N~T////NiNO'='v=T

0a

XXW\\ 1AIWA

"VaV.11,ARRE L

INJECTIO NORIFICE S

CHAMBE R

BREECH

SEALS

REGENERATIV E

PLUG

PISTONCOMBUSTIO N

CHAMBE R

Figure 1 . Schematic of a Simple Inline Regenerative Test Fixture .

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Infection Piston\\\\\Val\e Bock \\ LP Reservoir

Damper

\\\\ \\\\\\

Figure 2. Diagram of the General Electric Concept VIC RLPG .

Some of the present research anddevelopment concerns with an RLP Gsystem are reliability, safety, pressureoscillations in the combustion cham-ber, and need for high-energy liqui dpropellants . The complexities of thesystem and the high-pressure environ -ment create concern over the reliabil-ity and life of the seals, regenerativ episton, and other internal compo-nents, particularly in a field environ-ment. In addition, high-amplitude ,high-frequency pressure oscillationsthat are not characteristic of classica lcombustion instability have beenmeasured during the ballistic cycle.Concern over erosive effects on th ebarrel and on the reliability of th eregenerative components has prompt-ed research into the cause and elimi-nation of these oscillations .

The injection process in this gu nsystem has the major effect on th eballistic process . As a result, numer -

ous studies and modeling efforts tha tcharacterize the jet spray, drople tbreakup, and combustion are in prog-ress . The interior ballistic model sthat have been developed so far ex-hibit good agreement with the experi-mental data .

This gun system has matured sig-nificantly in recent years to the poin tthat a second generation 155 m mRLPG, referred to as the Concep tVIC, is presently being fabricated an dtested by the General Electric Com-pany (Figure 2). In this gun, theliquid propellant is injected betwee nthe two moving pistons into the com-bustion chamber . This RLPG has aredesigned damper assembly as well ,which is the major improvement overthe first generation RLPG .

The RLPG is only one of severa lArmy research and developmen tefforts for improving or replacing

conventional gun systems. Thosewho want further information on thisparticular gun system should refer t oCPIA LS89-11 . Future Bulletin arti-cles will discuss advanced gun sys-tems. For more information, contac tSharon Hasty (CPIA) at (301) 992 -7306.

References :

Coffee, T. P . and Wren, G . P ., "Prediction ofGun Performance for a Second Generatio n155mm Concept VIC Regenerative Liquid Pro-pellant Gun," to be published by CPIA in 27t hJANNAF Combustion Subcommittee MeetingProceedings (Summer of 1991) .

Klein, N ., "Liquid Propellants for Use i nGuns," in Gun Propulsion Technology (AIAA) ,Chapter 14, 1988, pp. 473-497 .

Morrison, W . F., Knapton, J. D., and Bul-man, M . J ., "Liquid Propellant Guns," TechnicalReport BRL-TR-2853 (AD-A188 575), October

1987, 87 pp .

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S&EPS Workshop on CFC AlternativesUpdate on CFCReplacement

Since the Montreal Protocol up -date article appeared in the August1990 CPIA Bulletin (Vol . 16, No . 5) ,concern has risen over the green -house potential of chlorofluorocarbo n(CFC) replacement compounds .

It was reported in Chemicalweek(Dec. 5, 1990) that the 1990 Interna-tional Conference on Chlorofluoro-carbon and Halon Alternatives, heldin Baltimore, Maryland in Novembe r1990, focused attention on the effec tof the nonozone depleting hydro -fluorocarbons (HFCs) on globalwarming . Although the developers o fthe HFCs say that the effect on glob -al warming is marginal, they are con-cerned about continuing shifts inregulations confronting users andindustry while CFC alternatives ar edeveloped. Both the Montreal Proto-col and the Clean Air Act now cal lfor the phaseout of CFCs, halons ,and carbon tetrachloride by 2000 andmethyl chloroform by 2005 . Thisconcern was underscored by an EP Aprediction that the 2000 deadline maybe pushed up to 1997 .

Even more dramatic were th elatest NASA findings on the deterio-ration of the Earth's ozone layerreported in Chemicalweek (April 17 ,1991) . The findings indicated that a4-5% depletion in the ozone layerover the U.S. is indicated since 1978 .They also show a global ozone de-crease of 2 .6%/decade and, ominous-ly, large depletions over the U .S. andEurope (all latitudes north of 30 N)during the winter . These depletionsare far greater than predicted bystandard computer models . TheNASA findings will almost certainlyincrease the pressure to speed up th ephaseout deadlines of the MontrealProtocol . For more information onCFC alternatives, contact Lee Piper(CPIA) at (301) 992-7307.

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The JANNAF Safety & Environ-mental Protection Subcommitte e(S&EPS) held a workshop on 2 6March 1991 to discuss recent effort sby the aerospace and ordnance indus-tries to identify and qualify replace-ments for halogenated solvents . Theworkshop was chaired by Mr. RandyWaskul of the Navy Ordnance Envi-ronmental Support Office, India nHead, Maryland . The workshopprovided several examples of effortsto replace halogenated chemicals wit heither aqueous- or semiaqueous-based solvents which, in contrast t oHFCs and hydrochlorofluorocarbons ,should not pose greenhouse concern s(see related CFC article to the left) .

Phaseout of CFCs . . .

may be pushed up to 1997

The workshop covered chlorinatedsolvent replacement efforts for awide range of applications includingmetal degreasing in thrust vecto rcontrol system servicing ; cleaning o fcomposite explosives process equip-ment; composite explosives loading ;munitions demilitarization (followin gwater washout) ; painting and spra yapplication of the thermal protectioncoating on parts of the Shuttle solidrocket boosters ; degreasing in solidrocket motor casting; and manufac-turing of nitroglycerine lacquer .

Several additional presentationsprovided valuable information con-cerning identification and qualifica-tion of CFC alternatives . The work-shop included a presentation on thedevelopment of an aqueous nonvola-tile residue analysis method for clean-liness verification with aqueous-basedsolvents . A presentation by Du Pon tcovered the advancements that thecompany has made in developingsemiaqueous-based cleaners . A de-

scription of the CFC alternative sinformation clearinghouse operatedby the Naval Sea Systems Comman d(NAVSEA) was presented. Finally ,papers identifying MILSPECS an dMILSTDS that specify the use o fchemicals regulated under the Mon-treal Protocol, as well as some of theprocesses involved in changing aspecification or standard, were pre-sented .

Recent work at the Naval Ord-nance Station, Indian Head, Marylandhas shown that methylene chloridecan be replaced by water as a diluen tin a nitroglycerine lacquer formula-tion. Although methylene chloride isnot (as yet) regulated under theMontreal Protocol, this is an exampleof a successful attempt to eliminate achlorinated solvent . This change wil lresult in the reduction of 42,000pounds of methylene chloride usedannually .

NAVSEA has initiated a compre-hensive program to address elimina-tion of CFCs . The program involve s1) identification of documents tha tspecify the use of regulated chemi-cals, 2) identification, testing, qualifi-cation, and approval of alternatives ,and 3) revision of specifications an dstandards. As part of this program ,NAVSEA is operating a CFC alterna-tives information clearinghouse(CIC). The CIC includes a databas eof alternative solvents containing dataon physical properties, material com-patibility, toxicity, environmentalproperties, commodity data, and userexperiences.

More detailed information is con-tained in the workshop report pre-pared by the S&EPS Environmenta lProtection Panel. To obtain a copyof the workshop report, contac tJames Cocchiaro (CPIA) at (301 )992-7305 .

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JANNAF MEETING CALENDA R

1991 Meeting Type Location Sec. ClassAbstract/Paper

Deadline

9-11 Jul Electro-Thermo Chemical Propulsion Workshop BRL, Aberdeen Unclassified/ N/A N/AModeling & Diagnostics (CS) Prov Grnd, MD Limited

22 Jul Rocket Motor Manufacturing Workshop NASA/Kennedy Unclassified/ N/A N/ASafety (S&EPS) Space Ctr ., FL Limited

22-26 Jul JANNAF Safety & Environmental Conference/ NASA/Kennedy Unclassified/ Past 8 Jul

28 Oct-1 Nov

Protection Subcommittee Meeting

28th JANNAF Combustion

Workshops

Conference/

Space Ctr ., F L

Brooks AFB,

Limited

Confidential/ Past 7 Oct

5-7 Nov

Subcommittee Meetin g

JANNAF Rocket Nozzle Technology

Workshops

Conference/

San Antonio, TX

NASA/MSFC,

Limited

Unclassified/ Past 22 Oct

1992

Subcommittee Meeting Workshops Huntsville, AL Limite d

24-28 Feb 1992 JANNAF Propulsion Meeting Conference Ft. Benjamin Confidential/ Past 30 JanHarrison &Westin Hotel ,Indianapolis, IN

Limited

Attendance at JANNAF Conferences and Workshops is by invitation only.

MEETING CALENDAR SUBJECT TO CHANGE FOR LATEST DETAILS, CONTACT CPIA at (301) 992-7306.

C

u l l e n CHEMICAL PROPULSIO NPS

ti INFORMATION AGENCYA

The Johns Hopkins University10630 Little Patuxent Parkway, Ste . 202, Columbia, MD 21044-3200

ADDRESS CORRECTION REQUESTED

Time Dated MaterialThe Bulletin is published bimonthly by the Chem -ical Propulsion Information Agency (CPIA). CPIAis a DoD Information Analysis Center responsibl efor 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 i scharged to subscribers . Also, subscribers must mee tsecurity and need-to-know requirements .

The Johns Hopkins Universit y10630 Little Patuxent Parkway, Suite 20 2Columbia, Maryland 21044-3200(301) 992-730 4Operating under Contract N00014-91-C-000 1

Ms . Catherine McDermott

Edito rMs . Lorri A. Pickett

Associate Editor

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