On Possibility of Detonation Products On Possibility of Detonation Products Temperature Measurements Temperature Measurements

of Emulsion Explosivesof Emulsion Explosives

Victor V. Sil’vestrov, S.A. Bordzilovskii,

S.M. Karakhanov, and A.V. Plastinin

Lavrentyev Institute of HydrodynamicsNovosibirsk, Russia

XII International Symposium on Explosive Production of XII International Symposium on Explosive Production of New Materials: Science, Technology, Business, and New Materials: Science, Technology, Business, and InnovationsInnovations (EPNM-2014)(EPNM-2014), , MayMay 25-30 25-30,, 2014, 2014, KrakowKrakow, , PolandPoland

GGoalsoals

1.1. Measurements of the detonation front Measurements of the detonation front temperature of emulsion explosives (EMX) temperature of emulsion explosives (EMX)

2.2. Why? Why?

– The temperature is the most sensitive detonation parameter to the EOS

– Development & calibration of EOS of detonation products for EMX, decomposition kinetics.

– Application of EMX to the delicate explosive welding is the reality today (thin foils, low-melting-point metals, tube plates and others).

3.3. Better knowledge of the EMX’s properties is Better knowledge of the EMX’s properties is needed.needed.

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EMX’s Temperature. ReviewEMX’s Temperature. Review

Numerical calculations:

• Yoshida M., et al.; Tanaka K.: 1985, 8th IDS – Kihara-Hikita EOS, 1900-2100 К1900-2100 К

• Odinzov et al.; Alymova et al.: 1994, Chemical Reports, BKW EOS; Combustion, Explosion, and Shock Waves, thermodynamic code, 1000-1000-1700 К1700 К

• Tanaka, 2005, APS-2005, KHT EOS, 1700 К1700 К

Experiment: single article single article Lefrancois A., et al. / Lefrancois A., et al. / 12th 12th Symp. (Intern.) on Detonation, 2002.Symp. (Intern.) on Detonation, 2002. Nitram explosive Nitram explosive (based on AN emulsion) (based on AN emulsion) – TTbb = 4179 K (?) = 4179 K (?)

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EMX compositionEMX composition

• OxidizerOxidizer – water solution of mixture AN & SN

nitrates, 94 wt. %

• FuelFuel – liquid hydrocarbon + emulsifier, 6 wt. %

• SensitizerSensitizer – glass microballoons 60 μm in size,

from 1 to 50 wt. % above an emulsion weight

• EMX parametersEMX parameters: density 0.5 – 1.3 g/cc,

detonation pressure 0.7 – 11 GPadetonation pressure 0.7 – 11 GPa, VOD 2.1 – 6

km/s, critical diameter 5 – 38 mm

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Measuring procedureMeasuring procedure

• Self-made four channel fiberfiber optical pyrometer optical pyrometer with quartz fiber 0.4/0.8 mm in diameter and up to 15 m in length

• Basis – Planck’ distributionPlanck’ distribution and Black bodyBlack body approximation

• Brightness temperatureBrightness temperature at 630(20)630(20) & 660(120) nm• FMP FMP – spectral range 300 ÷ 750 nm• CalibrationCalibration before each shot, lamp 1100 – 2350 K

and interpolation to higher temperature• Accuracy Accuracy 50-150 K 50-150 K

• Testing Testing – – PMMA, epoxy resin, PTFE at 1500-3000 KPMMA, epoxy resin, PTFE at 1500-3000 K • Details Details in Vestnik NSU, 2011, 6(1), 116-122 in Vestnik NSU, 2011, 6(1), 116-122 (in Russian) (in Russian)

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Experimental setup – Experimental setup – window techniquewindow technique

1 – HV detonator, 2 – 5% EMX primer, 33 – emulsion explosive – emulsion explosive Ø55x250 mm (at max density Ø105x400 mm), Ø55x250 mm (at max density Ø105x400 mm), 4 – polypropylene tube with 5 mm wall, 5 – contact pin, 6 – PVF2 or manganin pressure gauge, pressure gauge, 77 – Plexiglas window – Plexiglas window 15 mm in thick, 8 15 mm in thick, 8 – mask Ø6 mm,Ø6 mm, 99 – optical fiber – optical fiber with 0.4 mm quartz core (to pyrometer) or with 0.4 mm quartz core (to pyrometer) or Visar probeVisar probe

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Luminosity signal interpretationLuminosity signal interpretationPurpose – the choose a point to measure the Temperature of Purpose – the choose a point to measure the Temperature of

Detonation Products according the classic ZND modelDetonation Products according the classic ZND model

0.7 GPa0.7 GPa

Registered profile (1) = hot spot (3) + Registered profile (1) = hot spot (3) + detonation temperature (2)detonation temperature (2)

Temperature (1), pressure (2), Temperature (1), pressure (2), particle velocity (3)particle velocity (3)

tRtR 1880 K1880 K

Main ideaMain idea CorrelationCorrelation of three profilesof three profiles

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Luminosity (1) & Temperature (2)Luminosity (1) & Temperature (2)

t1 – detonation reaches the EMX/window interface

PD = 4.4 GPatR = 0.65 μs

2140 K2140 K

PD = 10.7 GPatR = 1.3 μs

1940 K1940 K

mcs

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Brightness temperature Brightness temperature of detonation front of detonation front

vs detonation pressurevs detonation pressure (experiment)(experiment)

Correction model

500

1500

2500

3500

0 4 8 12

Pd, ГПа

Т, К

7 8

Ths

Γ = 0.8

Γ = 0.4

Tb

EMXEMX – – low-temperaturelow-temperature explosiveexplosive~ 2000 K~ 2000 K

Hot spots

Detonation front

TCJ, calculation

Pd, GPa

P

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Comparison with calculationsComparison with calculations EMXEMX based on ANbased on AN//SNSN emulsionemulsion

500

1000

1500

2000

2500

0 4 8 12

Pd, ГПа

Т, К

1 3 6 7

calculations

experiment

Pd, GPa

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Lefrancois A.,Lefrancois A., et al. //et al. // 1122th Symp. (Intern.) on Detonation, 2002,th Symp. (Intern.) on Detonation, 2002, 432-439432-439 Temperature and pressure measurements comparison of the aluminized Temperature and pressure measurements comparison of the aluminized

emulsion explosives detonation front and products expansionemulsion explosives detonation front and products expansion

Nitram “a”Nitram “a” explosive explosive (based on AN (based on AN emulsion) withoutemulsion) without aluminumaluminum → → 4179 К4179 К

French producer calculation isFrench producer calculation is 21702170  ÷÷  2500 К2500 К

about two times lowerabout two times lower ! !

according our methodology T = 2200 ÷÷ 2300 K at 0.7-0,8 μs behind detonation front

ConclusionsConclusions

• The The alternative view on the structure of the spectral alternative view on the structure of the spectral radianceradiance signal recorded at detonation of an emulsion an emulsion explosiveexplosive with embedded glass microballoons

• The location of the pointThe location of the point to estimate the detonation temperature is defined by the comparison of pressure, by the comparison of pressure, particle velocity and temperature profiles behind the particle velocity and temperature profiles behind the detonation frontdetonation front

• Our experimental results are in qualitative and in qualitative and quantitative accordancequantitative accordance with independent calculations

• In the range of detonation pressures from 1 to 11 GPafrom 1 to 11 GPa the detonation temperature of EMX isthe detonation temperature of EMX is 1840 ÷ 2260 K1840 ÷ 2260 K and has non-monotonous behavior on pressurenon-monotonous behavior on pressure.

• Temperature maximum is about at 6 GPaTemperature maximum is about at 6 GPa

AcknowledgmentsAcknowledgments

The work was supported by

1. the Russian Foundation for Basic Research (project 12-08-00092-а),

2. the Presidium of the Russian Academy of Science (project 2.9),

3. the President of the Russian Federation for State Support of Leading Scientific Schools (grant NSh-2695.2014.1).

THANKS YOU FOR ATTENTIONTHANKS YOU FOR ATTENTION

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Appendix

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Detonation temperature measurement of Detonation temperature measurement of heterogeneous explosives / Problemsheterogeneous explosives / Problems

Optical methodOptical method based on the radiance of shocked/reacted matter hi-time resolutionhi-time resolution

Transparent window technique Transparent window technique / low shock impedancelow shock impedance material is needed for EMX’s material is needed for EMX’s

InterpretationInterpretation: short reaction time luminosity maximum to temperature estimation / longer reaction time longer reaction time (?)(?)

Mismatch of acoustic impedancesMismatch of acoustic impedances of window material and explosive investigated complexity of result’s analysis / EOS of detonation products, black/grey/non-equilibrium EOS of detonation products, black/grey/non-equilibrium body model, effect of physical inclusionsbody model, effect of physical inclusions

High “hot spots” temperature / Low “matrix” temperatureHigh “hot spots” temperature / Low “matrix” temperature very large dynamic range of technique used, high sensitivity

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Planck’ distributionPlanck’ distribution

Two wave lengthsTwo wave lengths

630 (20) nm630 (20) nm x 45 timesx 45 times

660 (120) nm x 38 times

TT630 630 - T- T660660 ≈ 30-50 K≈ 30-50 K

Wide dynamic range of pyrometer is needed to register and “hot spots”, and detonation temperatures

0

0,5

1

1,5

2

2,5

3

3,5

0,2 0,7 1,2

3000 K

2000 K

Ths

Td

visible range

630 nm 660 nm

l, μm

E

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Shocked mono-layer luminosityShocked mono-layer luminositymodel of “hot spots” layermodel of “hot spots” layer

20 GPa

9 GPa

t = 0.2 – 0.6 t = 0.2 – 0.6 ssTThshs ~ 1.5-2T ~ 1.5-2Tmatrixmatrix

5-10 mm

2.4 – 5.1 km/s

Explosively driven duralumin plate

Optical fiberØ0.2 mm, ~ 10 m

GMBs~ 60 μm

to FMT

filter

Matrixepoxy, water

~ 18º

maskØ6 mm