Simulation of the Effects of an Air Blast Wave - ELSA - Europa

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analytically, and a program written in C++ can be used for the approximation. The listing is shownin the appendix.At the first step the negative pressure with the values from Kingery are used. The results for b differfrom the function of Kinney [13] and Baker [3] (see Figure 6). The comparison of the resultedimpulses (see Figure 7) shows that the parameter b calculated with the minimal pressure in thenegative phase gets a too small positive impulse and should not be used.108KinneyBakerb [-]64Parameter b by using pminParameter b by using theimpulse of the postive phase200 5 10 15 20 25 30 35 40Z [m/kg 1/3 ]Figure 6: Decay parameter b – different methods14
250200Impulse from KingeryImpulse with b from KinneyImpulse with b from BakerImpulse with b by using pminImpulse [Pa sec]1501005000 2 4 6 8 10 12 14 16 18 20Scaled distance Z [m/kg 1/3 ]Figure 7: Decay parameter b – resulting impulse in comparison with the impulse from KingeryTherefore, the parameter b is next calculated using the impulse of the positive phase. Then, theresulting curve of b is similar to the curves of Kinney and Baker. The exponential trend line givenby Excel has the following equationb1.1975= 5.2777⋅ Z −(11)The pressure time curve that is built with this b doesn’t fulfil the minimal pressure in the negativephase. Sometimes the pressure p is smaller than the atmospheric pressure. This results in animpossible state of the air. Therefore, the approximation of the negative phase is done with abilinear curve shown in equation (12) and Figure 8 by using the values of the negative phase shownin section 2.2.4.⎛tt ⎞ dp= p0 + pmax⎜1 − ⎟ for t < td⎝ td⎠2 pntnp= p0− ( t− td) for t > td ∧ t < td+t22 pntnp = p0− ( t + t − t) for t > t + ∧ t < t + tt2p= p for t > t + t0nnbt−d n d d ndn(12)15
Page 1 and 2: Simulation of the Effectsof an Air
Page 3 and 4: Distribution ListLechner S.Anthoine
Page 5 and 6: 1 IntroductionThis work is being co
Page 7 and 8: • Far zone. The blast wave result
Page 9 and 10: Figure 2: Model of Kingery [14] wit
Page 11 and 12: 2.2.3 ImpulseThe impulse of the air
Page 13: Figure 5: Different parameters for
Page 17 and 18: the specific heat ratio and the spe
Page 19 and 20: determined with a fluid pre-calcula
Page 21 and 22: From this asymptotic form it can al
Page 23 and 24: 2.0E+101.6E+10without burn mass fra
Page 25 and 26: Case opening d pyra d ex,in d ex,en
Page 27 and 28: Pressure [Pa]2.4E+102.0E+101.6E+101
Page 29 and 30: 5.0E+094.0E+09EUROPLEXUS x=0.105EUR
Page 31 and 32: Cased pyr /d ex,in /d ex,end /d air
Page 33 and 34: Figure 21: Comparison of a coarse w
Page 35 and 36: CON9This model has approximately th
Page 37 and 38: 4E+7Max. pressure [Pa]3E+72E+7Kinge
Page 39 and 40: Case Size of the model Description
Page 41 and 42: CUB4This model uses a finer mesh th
Page 43 and 44: 6. Complete the volumes by adding t
Page 45 and 46: Figure 33: Maximum pressures versus
Page 47 and 48: experimental values is obtained wit
Page 49 and 50: 4.6.3 Arrival TimeThe arrival time
Page 51 and 52: value in [13]). These results show
Page 53 and 54: Modell airl bBubbleBubbleBubbleTNT
Page 55 and 56: Several calculations are done with
Page 57 and 58: 3. Calculation of the factor α bub
Page 59 and 60: quadratic. Therefore, the size of t
Page 61 and 62: 400Impulse [Pa sec]300200.Kingery 5
Page 63 and 64: 5 = hemispherical detonation (half
Page 65 and 66:
9 References[1] Alia, A.; Souli, M.
Page 67 and 68:
10 Apendix10.1 EUROPLEXUS Codedyms.
Page 69 and 70:
CALLMECVAL(GET_FMT(6),NEWMAT%MATVAL
Page 71 and 72:
10.2 Miscellaneous codeairblastresu
Page 73 and 74:
else{ //Kingerydouble t=log10(z);do
Page 75 and 76:
maxar=0;REPE I0 (NBEL vges);ar = as
Page 77 and 78:
*defining the surfaces around the a
Page 79 and 80:
lpyr1 = p1 d ppy2;lpyr2 = p1 d ppy3
Page 81 and 82:
lpyr2 = p1 d ppy3;lpyr3 = p1 d ppy4
Page 83:
*Cube intermediaire (centre=o0 et a
Page 86:
The mission of the JRC is to provid
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