,2 .y

TECHNICAL REPORT BRL-TR-3188

BRL0N0 HEATS OF EXPLOSION AT LOW PRESSURES

N

I ARTHUR COHEN4MARTIN S. MILLER

HUGHES E. HOLMVESBONITA A. HUNTLEY. pTIC

IIELECTEDECEMBER 199 0 S JI AN 24191U

"MOV M-U R* WXAWSri D~WroU1ON UNUMTMhD

U.S. ARMY LABORATORY COMMAND

BALLISTIC RESEARCH LABORATORYABERDEEN PROVING GROUND, MARYLAND

91 4,,l

NOTICES

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The use of trade names or manufactuerse names in this report does not constitute indorsement ofany comme cial product.

REPORT DOCUMENTATION PAGEI w Aed

6~a~ for the 9=49nfW iW~ft~1& 46 sw.ffiM to "Wow w "w evo. W-w a" . sa Nq.Cqdo _____ M WP - "ww tCW~tO O A90"1 WWVU Oawoi y

A1. KNY USE ONLY (LsVe him*) 1.REOThAE 3. REPORT TY PE AD DATES COVERED

IDecember 1990 Final Oct 89 - Jan 90

FHEAS O EXLOSON T LO PRSSUES.11.1L161 102AH43

* Arthur Cohen, Martin S. MillerHL-hes E. Holmes, Bonita A. H-untley

7 P1 FORMING ORGANIZATION NAME($) AND AOORESS4ES) 1. PERFORMING ORGANIZATIONREPORT NUM81ER

* ~ . SoNsoRNG, / MONITORING AGENCY NAME(S) AND 06004ESSEES) 10. SPOJ#SORIG I MONITORINGAGENCY REPORT NUMIER

Ballistic Research LaboratoryATTN: SLCBR-DD-TBR--38Aberdeen Proving Ground, MD 21005-5066 R-R38

-11I. SUMCM(MNTARY NOTE$

Part I of this report is BRL-TR-3024, dated August 1989. The title and the authors

are the same.

Ila DISTRIUTIfQ40itAVAI PLIuTY STATEMENT - - if. DISTRISUTION CODE

Approved for public release;distribution unlimited

An alternate method for estimating the thermal energy (E) of propellant combustion

products in guns at low pressures has been investigated. The method assumeg that

Ifor same pressure levels in guns and calorimeter bomabs, E is equal to tile measured

heat of exploston 01MX. i1EX have been measured in calorimeters for 4130 and X0t9 atlow initial pressures (Po) (25-1015 psia). Low loading, densities (U.) (.0002-.012 g/cc) were used to minimize the uncertainty in the calorineter pressure level

during combustion. The values for IiLX, at the higher L0, imply that combustion is

complete. As 1Pa and 1.0 decrease, a fall off in HFX from the va'lues obtained at the

higher U) is observe-d. This is attributed to a change in the combustion mechanlism

which leads to incomplete combustioni. IiL% values in the fall off region are also

dependent on the physical environnent in the calorimeter. This implies that some

knowledge of the physical processes which occur during combustion at low pressuresin calorimeter bombs (and tguns) is required to assess the usefulness of estimatingvalues for E from the HEX measurements.

ft 4 SAACT Sl~M SIS WANUM OF ;M5E

Heats of Ep '.Propellants, '00, LOVA., Heat of Combustion.,

Low PregsureI&PuCD

IV. UWUamTY cAs'sSC"fO 111. SECJURTY CLASIAT M3 LOUM? "SSIPICATMO 2. IWTATION OF AASTUACof REPONT 00 TNO PAGE of ASITRACT

Unclassified Unclassified W" Un1classified UL

11NP ?StOIZ3O4S0 Stan~dard Foroz 196 11w 249)

frNTENioNP.LLY Lmn BLANK

TABLE OF CONTENTS

PA•E

LIST OF FIGURES ............................................. v

ACKNOWLEDGEMENT ....................................... vii

L INTRODUCTION .............................................. 1

IL EXPERIMENTAL TECHNIQUE ................................... 1

III. EXPERIMENTAL RESULTS ...................................... 4

IV. DISCUSSION OF RESULTS ...................................... 7

V. SUM M ARY ................................................. 12

REFERENCES ............................................... 14

DISTRIBUTION LIST .......................................... 15

Aooe0 o•-5 Fo ..NTIS GRAE I

DTIC TABUnanuou1nQod QJustiflcatlon

Dlstribution/

Avallability Codes

Dist Special

S'1 ..

iii

rNTENioNALiy LEFT BLAN&

iv

LIST OF FIGURES

FIaum PAGE

1 Ignition Characteristics of Parr Calorimeter System with.016" Ni Fuse W ire ............................................. 5

2 Piezoelectric Transducer Signal: Transient Pressure DuringCombustion and Cooling in the Calorimeter ......................... 6

3 Dependence of Experimental Heats of Explosion on InitialPressure for M 30 .............................................. 7

4 Dependence of Experimental Heats of Explosion on InitialPressure for )XM 39 ............................................. 8

5 Dependence of Experimental Heats of Explosion on LoadingDensity for M 30 ............................................... 9

6 Dependence of Experimental Heats of Explosion on LoadingDensity for XM39 ............................................. 10

7 Maximum Total Pressure and Heats of Explosion: Selected M30Data to Show Pressure and Loading Density Effects onExperimental Heats of Explosion ................................. 11

8 Maximum Total Pressure and Heats of Explosion: Selected XM3SData to Show Pressure and Loading Effects on ExperimentalHeats of Explosion ........................................... 12

v

INTENTiow.L!LY LEFvr BumN

vi

ACKNOWLEDGEMENTS

The authors would like to thank E. Freedman (Eli Freedman & Associates,Baltimore, MD) for help with the BLAKE calculations and T. Tingle (Parr Instrument Co.,Moline, IL) for helpful suggestions concerning operation of the calorimeters.

vii

lmmNiomuLY Lmr BLARx

L INTRODUCTION

The work presented in this report is a continuation of a former program1 in whichthe pressure dependence of heats of explosion (HEX) for RDX (secondary explosive),XM39 (RDX composite propellant) and M30 (triple base propellant) were determined. Themeasurements were made in calorimeter bombs which were prepressurized tc variouslevels with inert gas (He or No. Low loading densities (.0002-.012 g/cc) were used inorder to minimize the transient pressure increase during combustion.

The program was started to provide information which could help improve interiorballistic (IB) code predictions of gun performance at low pressures. The discrepanciesbetween measurements and predictions of ignition delays and pressurization rate in gunsand gun simulators was discussed at a recent JANNAF workshop.2 It is generally believedthat the discrepancies at low pressures are due to two assumptions: (1) infinite-ratekinetics (to calculate the rate of energy production) and (2) thermodynamic chemicalequilibrium (to calculate the thermal enerr'y (E) of the propellant combustion products).The validity of these assumptions becomes questionable as pressure decreases. Theabsence of thermochemical equilibrium among combustion products under low pressureconditions is not unexpected. It is consistent with the HEX measurements at lowpressuresI and with strand burner observations of two stage propellant flames1 .3 where,below a critical pressure, the second stage (and thermochemical equilibrium) is inhibited.The use of finite rate kinetics will, in principle, eliminate the need for both theseassumptions but acquiring the necessary information for incorporation into the codes willtake time. The objective of the program was to evaluate an alternate method forestimating values of E which is independent of the thermochemical equilibrium assumptionand can be incorporated into the IB codes relatively quickly. This alternate method is tosubstitute for the value of E at a given gun pressure the HEX value measured at the samepressure in calorimeter bombs. This implicitly assumes that combustion and coolingprocesses in bombs and guns axe similar, If this assumption is valid then the HEXmeasurements at various pressurization levels are expected to be better estimates of Ethan the calculated themochemical equilibrium values that are now being used in IBcodes. There is the additional requirement (for use in the IB codes) that these processesdepend primarily on total pressure (Le., are not strongly dependent on gas composition).

The earlier workI showed th* as initial (ineit) pressures (Po) and loading densities(LI)) decreased there was a fall off in measured HEX and ignition became more difficult.The goal of tlis work is to extend the HEX measurements to lower LD in order to minimizeuncertainties in the pressurization level in the calorimeter. At low LD the ignition energycan be comparable to the combustion energy and must be subtracted from the (total)thertal energy of tlm calorimeter to obtain HEX values.

L EXPER2 AL TECHNIQUE

The experimental technique has been described previously.1 HEX were measuredwith a Parr Calorimeter System. The bombs (volume = 340 cc) were modified to providefor iransient pressure measurements and sampling of combustion products. The data

reported here are for perforated propellant grains except for a few XM39 data which weretaken with propellant slabs (solid).

It was possible to obtain data for M30 at lower LD (and Po) by using largerdiameter (.016" 'vs .006" Ni) ignition wire and increasing the wire area in contact with thepropellant, i.e., increasing ignition power and energy to the propellant These data aredenoted in Table 1 as enhanced ignition. For XM39, it was also necessary to placeZirconia Felt (Zicar Products), a thermal insulator, at the bottom of the capsule whichsupports the grains in the calorimeter during ignition and fiamespreading (i.e., decreasethe the heat transferred from the propellant) in order to obtain data (denoted in Table 2as thermal insulation) at lower LD.

TABLE 1. M30

PO M <HEX> Sh <pI§ SP

(psia) Gas, (g) (cag) Nh (cal-g) (psi) Np (psi)

1015 He 1 963 2 9 476 2 1961015 N2 1 977 2 9 329 2 491015 He .28 943 5 7 131 5 551015 NZ .28 945 2 10 108 2 51015 He .16 893 2 46 103 2 51015 He .08 838 4 32 60 2 1

465 He 1 958 2 20 628 2 52465 He .28 956 3 19 89 3 43

165 He 1 943 4 8 352 2 81165 N2 1 913 2 4 301 1 --165 He .28 923 3 6 57 3 28165 Na .28 870 1 -- 93 1 --

65 He 1 927 3 11 200 2 5665 He .28 864 2 32 --- 065 Na .28 777 2 12 61 2 1

-- - 1 I - 2445 He 1 918 S 17 171 4 3945 He .28 818 4 11 34 4 13

25 He 1 911 3 34 190 --

25 N2 1 928 2 13 - 0 --25" He .28 693 6 81 17 5 925" N2 .28 723 2 29 25 2 1825° He .16 826 2 119 12 2 125" He .08 587 2 176 13 2 1

2

"- - TABLE 2. XM39

Po m <HEX> Sh <P*> Sp(psia) Gas (g) (cal/g) Nh (cal/g) (psi) Np (psi)

1045+ He 4.4 829 1 --- 0 --

_ 940 He 2.2 830 2 0 (600) 1 --

940 NZ 2.2 835 1 -- 1072 1 -

940 He .52 810 3 12 272 1 --

- 940 N2 .52 802 2 5 216 1 --940 He .24 794 4 23 123 4 8940 He .13 731 2 4 80 2 10940 He .07 661 2 90 38 2 12

795+ He 2.2 822 1 -- -- 0 --

545+ He 4.4 833 1 -- -0 --

465 He 2.2 825 2 3 (600) 1 --

465 N2 2.2 823 1 -- 880 1 --

465 He .52 810 2 7 182 2 4465 N2 .52 798 2 27 163 2 4

295+ He 4.4 830 1 -- -- 0 --

245+ He 4.4 832 1 .... 0 --

245+ He 2.2 807 1 -- -0 --

240 He 2.2 825 2 4 452 1 --

240 N2 2.2 819 2 2 594 2 24240 He .52 769 2 36 123 2 4240 N2 .52 759 2 11 128 2 7

165 He 2.2 812 2 14 312 2 78165 142 2,2 804 1 - 480 1 --165 He .52 739 5 51 71 5 15165 N2 .52 712 2 14 86 2 7

45 He 2.2 818 2 25 108 1 --

45 He .M2 711 2 29 29 2 145$* He .24 578 3 82 7 2 145$* He .14 581 3 57 7 2 145$* He .07 529 2 83 7 2 4

+ = Slab$ = Thernal insulation

= Enhanced ignition

3

The ignition energy was obtained by integratirtg (over time) the product of theinstantaneous ignition voltage and current. The Paar Calorimeter System uses atransformer to provide a 60 Hz ignition voltage. ThK'• was measured. The ignition currentwas measured using a Pea son current monitor (Model #411) (Pearson Electronics, Inc.).

III. EXPERIMENTAL RESULTS

Figure 1 shows the instantaneous ignition voltage, ignition current and calculatedignition energy using .016" Ni ignition wire for an experiment with 1.03 g M30 propellantin N2, Po = 465 psia.. The ignition energy is 18.3 cal. which is about 2% of the total heatmeasured in tha calorimeter. Figure 2 shows the corresponding pressure increment whichis obtained frow the piezoelectric transducer signal. The pressure measurement is subjectto error due to heating uhf hte piezoelectric transducer during the experiment. Efforts weremade to mirdnmizm this heating by shielding with vacuum grease but were not entirelysuccessful. At present, it has been a&%sumed that the maximum pressure increments (P*)are not greatly affected by changes in heating due to differences in LD.

The data reported earlierl did not include corrections for ignition energy. Thesecorrectic - ilve been made for the data presented in Tables 1 and 2. Table 1summarL..s tie HEX and P* measuremrents for M30. m is the sample mass (±.10%), < >signifies the mean of the measurements, Nh and Np are the number of HEX and P*measurements, respectively, Sh and Sp are the corresponding standard deviations. Thecorresponding information for XM39 is given in Table 2.

Various plots of the data in Tables 1 and 2 are shown in Figures 3 through 8. Figure3 is a plot of HEX vs. Po for M30 which shows the effects of changes in mass and ambientgas on the measurements. At Po ; 465 psia, for both m = I g and m = .28 g, HEX valuesare relatively constant (-950 cal/g) and (at Po - 1016) equal in He and N2. At Po .5165 psia, for in = 1 g in He, there is some indication of a fall offin HEXvalues. At Po <= 165 psia and m = .28 g, the fall off is obvious for both gases and HIEX appear to besmaller in N2 than in He (data at Po = 25 psia have large scatter).

Figure 4 is the corresponding plot for XM39. EX appear to be equal for grains(perforated) and slabs (solid) and slightly less in N2 than in He. At Po a 465 psia, theHEX values for m a 2.2 g are relatively constant (-820 cal/g) and those for m = .52 g areslightly smal, or but also appear to be constant (-800 calfg). At Po : 240 psia there islittle change in MEX with m a 2.2 g but there is an obvious fall off in HEX for m = .52 g(in both He and N2).

Figure 6 is a plot of HEX vs. i for M30. This figure shows the fall off in HEX withm (or LD) at two different initial pressures. The fall off for Po - 1015 psia is noticeableat m < .28 g. At rn = .08 g, HEX = 838 cal/g and the corresponding operating pressurerange (Po - (Po+P') for values of Po and P" listed in Table 1) is 1015-1075 psia. For Po= 25 psia the fall off in E with m is noticeable at m = 1 g. The fall off appears to beinterrupted between mi .0= g and m = .28 g, data taken under 'enhanced ignition"conditions. These data have large scatter and the change in behavior may not be real.

•Nm "4

W.6

6.53 7K. W~3b 1..

-"'@

1.1 MA

~ VMS

V

We,

O4's..

UM*

Figure 1. Ignition Characteristics of Parr Calorimeter System with .0 16t1 Ni Fuse Wire.(a) Ignition voltage (GO Hiz)- increase in voltage at Time = 294 m, is due to cessation

of current Hlow. (b) Ignition current (60 Hz). (c) Ignition energy: calculated fromintegration (overtime) of the product of instantaneous voltage and current shown

in (a) and (b).

5

At m = .08 g, HEI. = 587 cal/g and the corresponding operating pressure rarge is 25-38psia.

388 .8

.94

aA 288.6

18.06 "

8] ". 2.5. 5.81 7.5aII Kt

Figure I Piezoelectric Transducer Signal: Transient Pressure During Combustion andCooling in the Calorimeter. Signal was processed by a 30 Hz electronic filter to reducenoise duing ignition.,

Figure 6 is the com.r.ponding plot (to Fig. 3) for XM39 data. The fall off in HEXwith m for PN = 940 psia is notice,,ble at m < .52 g. At m = .07 g, HX = 661 cal/g andthe corresponding operating pressure range is 940-978 psia. For Po = 45 psi,., the fall offstarts at m < 2.2 g. At m = .07 g, HEX=829 cal/g and the coresponding operatingpressure range is 45-52 psia.

The fall of in HEX with m at fixed Po and especta:ly for small values of m suggestthat X are not solely dependent on the operating pressure level in the calorimeter. Thiswill make it dilmcult to use meaureO I.EX for estimating values for E.

The data in Figure 7 derm~onstrates that HEX for M30 is not solely dependent onpressure levels in the boiab during burning, buit cmi depend on loading density. The datafor .28 and 1.0 g (light points) indicate that HEX increase slightly with maximum totalpressure (initial pressure + meastirud maximum pressure incre~nent) but are not greatlydependent on mass. The data for .08 rud .16 g (dark poAnts) have initial pressures (i.e.,minimum bomb pressures) = 1000 psia. HEX fo. these data are lower than HEX for thedata obtained at higher loading densities (seven points) although five of the latter datahave maximum bomb pressures < 600 psia. For these experiments, it appears that HEXdepc•nd more strng y on loading density (Le., the concentration of combustion productsin the bomb) than on pressure levels.

6

HEX Dependence an Initial Pressure (M30)

1000 ,

L- 0

1-4

'• 900.

o o.

(3 0. g. grain in He

00.28 g. grain in He

.* 1 g. grain in N2700. 0 *0.2H g. grain in N2

600..000 200. 400. 600. 800. iW0O

INITIAL PRESSURE [ psia I

Fgure 3. Dependence of Experimental Heats of Explosiion on Initial Pressure for M30

Figure 8 is the corresponding plot (to Figure 7) for XM39 data. All data with totalmaximum pressures > 800 psia have Po = 940 psia. The other data have maximum totalpressure < 800 psia. Despite lower operating pressures in the calorimeter, HEX values form = 2.2 g with maximum total pressures < 700 psia appear to be greater than those thosefor m = .07, .13, and .24 g. This stronger dependence on loading density than onpressure is similar to the M30 behavior shown in Figure 7.

IV. DISCUSSION OF RESULTS

The data in Figure 3 for 1 g M30 suggests that HEX are not greatly dependent onPo for Po 2 25 psia and on pressurizing gas composition. The differences betweenmeasured HEX (911-977 cal/g) and those calculated (-955 cal/g) assuming a (generallyaccepted) freeze-out temperature greater than 1500 K is not great. This suggests that forPo > 25 psia combustion in the calorimeter is almost complete (iLe., combustion productscorrespond to a thermochemical equilibrium mixture) for 1 g samples. Comparison of

7

HEX Dependence an Initial Pressure (XM39)900.

800. -V

032.2 g. grain in He00.52 g. grain in He

.700. 0 • 4.4 g. slab in HeV2.2 g. slab in Hea 2.2 g. grain in N2@0.52 g. grain in N2

600. ..000 200. 400. 600. GOO. WOOo

INITIAL PRESSURIE [ psia I

flutm 4t Dependence of Experimental Heats of Explosion on Initial Pressure for XM39

measured and calculated HEX values for .28 g M30, at Pe = 465 and 1015 psia alsoindicate that combustion L almost complete. At lower Po (<465 psia) there is a fall offin MEX from the calculated values (the calculated values are not greatly dependent on Poor LD) for the .28 g samples. This fall off suggests that changes occur in the combustionmechanism (or extent of reaction) at low pressures which inhibit the establishment ofthermochemical equilibrium among combustion products.

The data in Figure 4 for 2.2 g and 4.4 g XM39 indicate that differences betweenmeasured HEX (800-835 cal/g) and calculated values (-810 cal/g) are small suggestingthat combustion is complete. Comparisons of the HEX values (7,8-810 callg) for .52 gXM39 with calculated values indicate that combustion is complete at Po > 465 psia. Atlower Po there is fall off in HEX values from calculated values, similar to the behavior withM30, indicative of changes in the combustion mechanism at low pressures and deviationsof combustion products from thermochemical equilibrium.

8

HEX Dependence an Mass (M30 in He)

1000

Ll 0600.

000

LL.

!~600. 0

0 Initial pressure = 1015 psia0 Initial pressure =25 psia

400. o.000 .200 .400 .600 .800 1.00

SAMPLE MASS [ g ]

FPIm 5. Dependence of Experimental Heats of Explosion on Loading Density for M30

The HEX calculations and reasons for the HEX dependence on initial pressures andloading densities has been discussed previously.1 The transition at lower Po and LD fromcomplete to incomplete combustion is attributed to a decrease in chemical kinetic ratesand the subsequent increased importance of transport rates (diffusion and heat transfer)in the combustion process. This increased dependence on transport processes underthese conditions is thought to be responsible for the increase in variability of the data atlow Po and low LD which can be seen from the values of the standard deviations (s) inTables I and 2. The small decrease in HEX when N2 is substituted for He at low Po andlow LD may be due to differences in transport properties of the gases.

The thermochemical properties of the propellant combustion products presentlyused in 1B codes are those calculated for closed bomb combustion products inthermochemical equilibrium at loading densities between .2- .33 g/cc. Blake4 calculationsfor M30 under these conditions give values for E (which do not greatly depend on LD)near 1025 callg. If the alternate method for estimating E which is now under consideration(Le., for a given pressure measured HEX and E values are equal) is valid then the HEX

9

HEX Dependence on Mass (XM39 in He)900.

S800. o0U

0S700.

S600. o

O Initial pressure 940 psia00 0 Initial pressure - 45 psia

400..000 i.00 2.00 3.00

SAMPLE MASS ( g I

Fgure 6. Dependence of Experimental Heats of Explosion on Loading Density for XM39

values for M30 in Figure 5 at m = .08 g indicate that in the pressure range 101541078 psia,E -838 cal/mole and in the pressure range 25-38 psia, E -587 cal/g. Although thecorresponding standard deviations for these measurements are quite large, 32 and 176cal/g, the difference between the calculated E and measured M are statisticallysignificant for both the high and low pressure ranges.

For X=39, the calculated E -898 cal/g. The HEX values for XM39 in Figure 6 atm = .07 g indicate that in the pressure range 940-978 psia, E -731 cal/g and in the range45-82 psia, E -529 cal/g. The corresponding standard deviations (4 and 83 cal/g) indicatethat the differences between calculated E and those based on the HEX measurements aresignificant.

Lower values for E may improve LB code predictions at low pressures but thesubstitution of measured HEX values for E in LB calculations requires that they beindependent of LD (Le., dependent only on total pressure in the calorimeter). It isnecessary to detennine if values for = measured at the lowest LD (m = .08 and .07 g

10

HEX Dependence on Max. P (M30 in He)

0• ,4 950.U 0 0

1- sp900.U

I-_M 0 1.0 g sample

850. 00.28 g sample850i E 1.16 g sample

SO.0B g sample S

000 . ,_I_ ..000 400. 000. 1200 1600

MAXIMUM TOTAL PRESSURE [ psia ]

Figure 7. Maximum Total Pressure and Heats of Explosion: Selected M30 Data to ShowPressure and Loading Density Effects on Experimental Heats of Explosion

in Figures 5 and 6, respectively) which have been used to make esimates of E, areconsistent with this requirement. The data in Figures 7 and 8 indicate that HEX values areaffected by changes in LD which suggests that the HEX have some dependence on theconcentration of combustion products in addition to the operating pressure levels in thecalorimeter.

It is noteworthy to emphasize that the effect of systematic errors in the calorimeterdetermination of thermal energy can greatly affect HEX values. Determination of thecalorimeter energy equivalent which is used to convert the calorimeter temperatureincrease into energy is obtained by a standardization method in which increases in thecalorimeter temperature are approximately 3* C. At low loading densities (m = .07 g), theincreases in temperature are approximately .03' C. Conclusions based on the low loadingdensity HEX values remain questionable without determining the validity of using thecalorimeter energy equilivalent for such small increases in temperature.

11

HEX Dependence an Max. P (XM39 in He)900.

u 0-' 000.zO

0'-4

700. 0 2.2 g sample00.24 g sample

O.013 g sample

@_0.01 0 6; omp I

0000. -s-ml-.000 400. 800. 1200 1600

MAXIMUM TOTAL PRESSURE ( psia I

Figure 8. Maximum Total Pressure and Heats of Explosion: Selected XM39 Data to ShowPressure and Loading Effects on Experimental Heats of Explosion

V. SUMMAIW

An alternate method for estimating the thermal energy (E) of propellant combustionproducts for calculating gun performance at low pressures has been investigated. Themethod assumes that at a given gun pressure, E is equal to the measured heat ofexplosion (HEX). HEX have been measured in calorimeters for M30 and XM39 at lowinitial pressures (Po) (25-1015 psia). Low loading densities (LD) (.012 -. 0002 g/cc) wereused to minimize the uncertainty in the calorimeter pr-essure during combustion. At thehigher LD, HEX values for M30 and XM39 were constant and not much different from HEXvalues calculated for an equilibrium combustion process. As Po and LD decrease, a falloff in HEX from the values obtained at higher L) and higher Po is observed. The HEXvalues in this low pressure fall off region are much less than calculated HEX and also thecalculated E values now used in gun calculations. HEX values in the fall off region may

12

also depend on the concentration of combustion products in the calorimeter. This latterdependence will increase the difficulties of using the HEX measurements in MB codes.

The HEX measurements in the fall off region are also dependent on the physicalenvironment. The addition of thermal insulation to the capsule which support thepropellant grains and changes in its location relative to the grains which affect transportprocesses during combustion also affect HEX values.1 This implies that some knowledgeof the physical processes which occur during combustion at low pressures in calorimeterbombs (and guns) will be required to asses the usefuilness of estimating values for E fromthe HEX measurements.

Future work to determine the magnitude of the calorimeter errors in measuringsmall thermal inputs is planned and an effort will be made to obtain information on thesensitivity of HEX measurements to the presence of combustion product gases and tosimulated (inert) propellant grains.

13

REFERENCES

1. A Cohen, M.S. Miller, ILE. Holmes, and BA Huntley, 'Heats of Explosionat Low Pressures", BRL Technical Report BRL-TR-3024, August 1989.

2. G.E. Keller, "Report on JANNAF Workshop: Influence of Gas PhaseChemical Kinetics on Low Pressure Ignition and Flamespreading in SolidPropellants", BRL-TR-2918, July 1988.

3. N. Kubota and T. Masamoto, "Flame Structure and Burning RateCharacteristics of CMDB Propellants", 16th Symposium (International) onCombustion, p. 1201, The Combustion Institute, 1976.

4. E. Freedman, "BLAKE - A Thermodynamics Code Based on Tiger: UsersGuide Manual", BRL Technical Report ARBRL-TR-0241 1, July 1982.

14

No of No ofCq e Organization Copies Or-ganization

2 Administrator 1 CommanderDefense Technical Into Center US Army Missile CommandATTN: DTIC-DDA ATTN: AMSMI-RD-CS-R (DOC)Cameron Station Redstone Arsenal, AL 35898-5010Alexandria, VA 22304-6145

1 CommanderHODA (SARD-TR) US Army Tank-Automotive CommandWASH DC 20310-00C1 ATTN: AMSTA-TSL (Technical Library)

Warren, MI 48397-5000Commander

US Army Materiel Command 1 DirectorATTN: AMCDRA-ST US Army TRADOC Analysis Command5001 Eisenhower Avenue ATTN: ATRC-WSRAlexandria, VA 22333-0001 White Sands Missile Range, NM 88002-5502

Commander (p& ,*)l CommandantUS Army Laboratory Command US Army Infantry SchoolATTN: AMSLC-DL ATTN: ATSH-CD (Security Mgr.)Ade[pWi, MD 20783-1145 Fort Benning, GA 31905-5660

2 Commander (uii=I& cS~l CommandantUS Army, ARDEC US Army Infantry SchoolATTN: SMCAR-IMI-1 ATTN: ATSH-CD-CSO-ORPicatinny Arsenal, NJ 07806-5000 Fort Bonning, GA 31905-5660

2 Commander I Air Force Armament LaboratoryUS Army, ARDEC ATTN: AFATIJOLOOLATTN: SMCAR-TDC Eglin AFB, FL 32542-5000Picatinny Arsenal. NJ 07606-5000

Aberdeen ProvinQ GrovndDirectorBenet Weapons LLaboratory 2 Olt. USAMSAAUS Army, ARDEC ATTN: AMXSY-DATIN: SMCAR-CCB-TL AMXSY.MP, H. CohenWatelviet, NY 12189.4050 1 Cdt. USATECOM

ATTN: AMSTE-TOCommander 3 Cdr. CRDEC, A.MCCOMUS Anry Armament, Munrtions ATTN: SMCCR-RSP-A

and Chemical Cormwin,, SMCCR-MUATTN: SMCAR-ESP-L SUCCR.MSIRock Island, i. 61299-5000 1 Dit. VLAMO

ATTN: AMSLC-VL-DDirector

US Arnry Aviation Research"and Technolgy Activity

ATTN: SAVRT.R (Library)WiS 219-3Ames Research CenterMoffelt Feld. CA 94035-1000

15

No. of No. ofCo-ies Organization _Qgin Organization

4 Commander 5 CommanderUS Army Research Office Naval Research LaboratoryATUN: R. Ghirardeili ATUN: M.C. Lin

D. Mann I. McDonaldR. Singleton E. OranR. Shaw J. Shnur

P.O. Box 12211 RJ. Doyle, Code 6110Research Triangle Park, NC Washington, DC 2037527709-2211

1 Commanding Officer2 Commander Naval Underwater Systems

US Army, ARDEC Center Weapons Dept.ATIN: SMCAR-AEE-B, D.S. Downs ATTN: R.S. Lazar/Codo 36301

SMCAR-AEE, J.A. Lannon Newport, RI 02=40icatinny Arsenal, NJ 07806-5000

2 CommanderCo(nmander Naval Weapons CenterUS Amiy, ARDEC ATTN: T. Boggs, Code 388ATTN: SMCAR-AEE-BDR, L Harris T. Parr, Code 3895Picatinny Arecnal, NJ 078&..5000 (Cina Lake, CA 93555-6A01

2 Commander I SuperintmedentUS Army Missle Command Naval Postgraduate SchoolA"IN: AMSMI.RK, Dept. of Aer,,autics

DJ. Ifshin ATIN: D.W. NctzerW. Wbtrtoo Mcuterey, CA 93940

Reedston Arsenal, AL 3S6983 AIJISCF

Commander AITfN: R, CordeyUS Army M Olo Comnmand R. Ocl~erAfIN: AMSMI-RKA, A.R. MNaykt1 J. le'ineKcds wn Arnl, AL 354*1-5249 Elwards A11, CA 3$23,S00G

Office at Naval Rcxivch I AI/MIKPBDeparumem of the Nav K AITN: 11. GCshrianA1I: R.S. Mgulcr. Cod 432 Edwards AM, CA 9352.35•,)800 N. Quincy StreetArUtqtON VA 22217 1 A MOS-1

ATfl4: J.M. TahJkaITCr nmanar Bolling Air ERce UnsuN-a.t Air S•,,errs Onma Wah.ngm. DC 2033.AiTN: J. Ramvsmte,

AIR-S4111C O¶)ISDIOilSTWasZwaglzx, M, um3G A*11h: L Camay

PentagonCommaNtr Wasu gton. DC 20301.7100Naal Sitnace Warfare CenterA'I-'" JL UEau. Jr., G-23 onwnndatD hen VA VA44-So0 USAFAS

AITN: AISIF-TSM.CN2 imiinander Fori S" OK 73503-S6W

Naval Surface Warfare CenterATMN: R. Bemte'er, R-13 I F.J. Seiler

G.B. Wawmo, R-16 AT]N: S.A. %aftkefordlr Spain& MD W90113-5=0 USA"~ Ac WO 60&"2S

16

No. of iqo. ofCl 2rWanizatorio Conies Organization

University of Dayton Research Institute 1 Battelle Memorial InstituteATTN: D. Campbell Tactical Technology CenterAIRPAP ATTN: J. HugginsEdwards AFB, CA ,3523 505 King Avenue

Columbus, OH 43201NASALangley Research Center 1 Cohen Professional ServicesLangley Station ATrN: N.S. CohenATTN: G.B. Northam/nIS 168 141 Channing StreetHampton, VA 23365 Redlands, CA 92373

4 National Bureau of Standards 1 Exxon Research & Eng. Co.ATrN: J. Hastie ATTN: A. Dean

M. Jacox Route 22ET. Kashiwali Annandale, NJ 08801H. Sr- -rjian

US Departmen. ., Commerce 1 Ford Aerospace andWashinqtor "C 20234 Communications Corp.

DIVAD DivisionI Aerojet Solid Propulsion Co. Div. Hq., Irvine

AT", ;: P. Micheli ATTN: D. WilliamsSa,..4mento, GA 95813 Main Street & Ford Road

Newport Beach, CA 92663Applied Combustion Technology, Inc.SATN1: A.M. Varney I General Applied ScienceP.O. Box 607885 Laboratories, Inc.Orlando, FL 32860 77 Raynor Avenue

Ronkonkama, NY 11779-66492 Applied Mechanics Reviews

The American Society of 1 General Electric OrdnanceMechanical Engineers Systems

ATTN: R.E. White ATN: J. MandzyA.B. Wenzel 100 Plastics Avenue

345 E. 47th Street Pittsfield, MA 01203New York, NY 10017

2 General Motors Rsch LabsAtlantic Research Corp. Physics DepartmentATTN: M.X. King AMTN: T. Sloan5390 Cherokee Aveante R. TeetsAlexandria, VA 22314 Warren, MI 48090

Atlantic Research Corp. 2 Hercules, Inc.ATTN: R.H.W. Waesche Allegheny Ballistics Lab.7511 Wellington Road AMTN: W.B. WalkupGainesville, VA 22065 EA Yount

P.O. Box 210AVCO Everett Research Rocket Center, WV 26726

Laboratory DivisionATTN: D. Stickler 1 Honeywell, Inc.2385 Revere Beach Parkway Government and AerospaceEverett, MA 02149 Products

ATMN: D.E. BrodcnlMS MNSO-2000

600 2nd Street NEHopkins, MN 55343

Sl 17

No. of No. ofgois OrDAnization Cooks Orrzanization

SHoneywcl, Inc. 2 Princeton Combustion

AITN: RE. Tompkins Research Lzboratories, Inc.

MN38-3300 ATTN: M. Summerfield

10400 Yellow Circle Drive NA Messina

Minnetonka, MN 55343 475 US Highway OneMonmouth Junction, NJ 08852

1 IBM CorporationAWTN: A.C- Tam I Hughes Aircraft Company

Research Division ATN: T ' Ward

5600 Cottle Road 8433 Fallbrook Avenue

San oose, CA 95193 Canoga Park, CA 91303

irr Research Institute I Rockwell International Corp.

ATIN: R.F. Remaly Rocketdyne Division

10 West 35th Street ATTN: J.E. Flanagan/HBO2

Chlcago, IL 60616 6633 Canoga AvenueCanoga PN1l, CA 91304

2 DirectorLawrence Uvermore 4 Sandia National Laboratories

Na:.ona! Laboratory Division 8354

AWfN: C. Westbrook ATrN: R. Cattolica

M. Costantino Johnston

P.O. Box 808 P. Mattern

Liveramoe, CA 94550 D. Siephensc,,Livermore, CA 94550

1 Lockheed Missiles & Space Co.

ATTN; George Lo Science Applications, Inc.

3251 Hanover Street AITN: R.B. Edclman

Dept. 52-35[0204/2 23146 Cumorah Crest

Palo Alto, CA 94304 Woodland Hills, CA 91364

1 Lm Alamos National Lab 3 SR! Internation'l

"AT'ITN: 13. Nichols ATIN: G. Smith

T1, MS-B284 D. Crosley

P.O. Box 1663 D. Golden

Lo Al•.uxNM 87545 333 Ravcnswood AvenueMenlo Park, CA 94025

SNatiomal Sciicve Foundation"ATTN: A.B. Harvey I Steve3 Institute of Tech.

Washlngton, DC 20550 Davidsim LaboratoryAT'TN: R. McAlevy, III

Olin Ordnance Hoboken, NJ 07030

ATTN: V. McDonald, LibaLryP.O. Box M2 Sverdrup TechtoVy, Inc.

StL Markt FL 32355-0222 LERC GroupATIN: RJ. Lockc, MS SVR-2

Paul Gough Associates, Inc. 2001 Aerospa= Parkway

ATTN: PS. Gough Brook Park, O1 44142

1048 Souih StreetPortsouth. NH 03801.5423 I 'hiokol Corpoation

lElkton Division

AITN" SF. PalopoliP.O. BkE 241-- ton, MI) 21921

18

No. of No. ofConie Oranization -Copes Organization

SMorton Thiokol, Inc. 1 University of California,Huntsville Division BerkeleyATFN: J. Deur Chemistry DeparmentHuntsville, AL 35807-7501 ATTN: C. Bradley Moore

211 Lewis Hall3 Thiokol Corporation Berkeley, CA 94720

Wasatch DivisionATIN: SJ. Bennett 1 University of California,P.O. Box 524 San DiegoBrigham City, UT 84302 ATTN: FA Williams

AMES, B010United Technologies Research Center La Jolla, CA 92093ATTN: A.C. EckbrethEast Hartford, CT 06108 2 University of California,

Santa Barbara3 United Technologies Corp. Quantum Institute

Chemical Systems Division ATrN: K. SchofieldATTN: R.S. Brown M. Steinberg

T.D. Myers (2 copies) Santa Barbara, CA 93106P.O. Box 49028San Jose, CA 95161.9028 1 University of Colorado at

BoulderUniversal Propulsion Company Engineering CenterAITN: HJ. McSpadden ATTN: J. DailyBlack Canyon Stage I Campus Box 427Box 1140 Boulder, CO 80309-0427Phoenix, AZ 85O29

2 University of SouthernVerltay Technology, Inc. CaliforniaAT'N: ElB. Fisher Dept. of Chemistry4845 Millersport Highway ATTN: S. BensonP.O. Box 305 C. WittigEast Amhert, NY 14051-0305 Los Angeles, CA 90007

SBrigham Young University 1 Case Western Reserve Univ.Dept. of Chemical Engineering Div. of Aerospace SciencesATTN: M.W. Beckstead ATTN: J. TienProvo, UT 84058 Clevcland, OH 44135

California Institute of Tech. I Cornell UniversityJet Propulsion Laboratory Department of ChemistryAT"l: L StrarWdMS 512fl02 AIIN: TA. Cool4800 Oak Grove Drive Baker LaboratoryPasadena, CA 91009 Ithaca, NY 14853

California Institute of 1 University of DelawareTechol, ATTN: T. lrill

A NTh: F.E.C CulickI Chemlstry DepartmentMC 301-46 Newark, DE 19711

27D Karman Lab.Pasadena, CA 91125 1 Unibrslty of Florida

Dept. of ChemistryUniversity of California ATTN: J. WinefordnerLas Alamos Scientific Lab. Gainesville, FL 32611P.O. iku 1663, Mail Stop 1216L.,s Abarm, NM 87545

19

No. of No. ofConies Organization Coies OrQranization

3 Georgia Institute of 2 Princeton UniversityTechnology Forrestal Campus Library

School of Aerospace ATrN: K. Brezinsky

Engineering I. Glassman

ATIN: FE. Price P.O. Box 710

W.C. Strahle Princeton, NJ 08540

B.T. ZinnAtlanta, GA 30332 1 Purdue University

School of Aeronautics SUniversity of Illinois and Astronautics

Dept. of Mech. Eng. AT1'N: J.R. Osborn

ATIN: H. Krier Grissonm Hall

144MEB, 1206 W. Green St. West Lafayette, IN 47906

Urbana, IL 618011 Purdue University

I Johns Hopkins University/APL Department of Chemistry

Chemical Propulsion ATrN: E. Grant

Information Agency West Lafayette, IN 47906

ATrN: T.W. ChristianJohns Hopkins Road 2 Purdue University

Laurel, MD 20707 School of MechanicalEngineering

SUniversity of Michigan ATTN: N.M. Laurendeau

Gas Dynamics Lab S.N.B. Murthy

Aerospace Engineering Bldg. TSPC Chaffee Hall

ATTN: G.M. Faeth West Lafayette, IN 47906

Ann Arbor, MI 48109-21401 Rensselaer Polytechnic Inst.

University of Minnesota Dept. of Chemical Engineering

Dept. of Mechanical ATIfN: A. Fontijn

Engineering Troy, NY 12181

ATTN: E. FletcherMimnnapolis, MN 55455 1 Stanford University

Dept. of Mechanical

3 Pennsylvania State Univcrsity Engineering

Applied Research Laboratory ATTN: R, Hanson

ATIN: K.K. Kuo Stanford, CA 94305

H. PalmerM. MIcci 1 University of Texas

University Park, PA 16802 Dept. of ChemistryATTN: W. Gardiner

Pennsylvania State University Austin, TX 78712Dept. of Mechanical Engineering

AITN: V. Yang I University of Utah

University Park, PA 16802 Dept. of Chemical EngineeringATI'N: G. Fiandro

I Polytechnic Institute of NY Salt Lake City, UT 84112

Graduate CenterATTN: S. Lederman I Virginia Polytechnic

Route 110 Institute and

Fartningde, NY 11735 State UniversityAWTN: J.A. SchetzBlacksburg. VA 24061

20

No. of No. of-- g p Organization £e•ie Organization

1 Freedman AssociatesATTN: E. Freedman2411 Diana RoadBaltimore, MD 21209-1525

21

INITXrIONALLY LEFT BLANK.

22

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