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MNGN 444 – Blast Overpressure and Positive Pulse Duration Curves
Reference: P.Cooper, “Explosives Engineering”, Chapter 28, 1996.
MNGN 444 – Height of Burst Curves
Reference: M.Mellor, “Explosions and Snow”, Cold Regions Science and Engineering, Part III, Section 3A, 1965.
MNGN 444 – Equations I
Reference: G.F. Kinney, K.J.Graham, “Explosive Shocks in Air”, Second Edition, 1985.
Shock Velocity:
𝑼𝒙 = 𝑪𝒂 ∙ √𝟏 +𝟔𝑷𝒙
𝟕𝑷𝒂
Mach number:
𝑴𝒙 =𝑼𝒙
𝑪𝒂
Blast Overpressure:
𝑷𝒙 =𝟕(𝑴𝒙
𝟐 − 𝟏)
𝟔∙ 𝑷𝒂
Angle of incidence:
𝜷𝒎𝒊𝒏 =𝟏. 𝟕𝟓
(𝑴𝒙 − 𝟏)+ 𝟑𝟗
Mach stem number:
𝑴𝒔𝒕𝒆𝒎 =𝑴𝒊𝒏
𝒔𝒊𝒏 𝜷
Ca is speed of sound in air (sea level)
Pa is atmospheric pressure (sea level)
Subscript x means general (Incident/Mach Stem).
MNGN 444 – Equations II
Reference: P.Cooper, “Explosives Engineering”, Chapter 27, 1996.
Gurney Equation:
𝑽𝟎
√𝟐𝑬= (
𝑴
𝑪+
𝟏
𝟐)
−𝟏/𝟐
M: mass of metal cylinder (kg) C: mass of explosive (kg) √2E: Gurney constant (m/s)
Mott Equation:
𝒎 = [𝑴𝒌 𝒍𝒏 (𝑴𝟎
𝟐𝑴𝒌)]
𝟐
Mo: mass of metal cylinder (lb) Mk: distribution factor
𝑀𝑘 = 𝐵 ∙ 𝑡5/3 ∙ 𝑑1/3 ∙ (1 +𝑡
𝑑)
B: Mott coeficient for given explosive-metal pair T: wall thickness (in) D: inside diameter of metal cylinder (in)
Fragment Size:
Drag Attenuation Equation:
𝑽𝒔 = 𝑽𝟎 ∙ 𝒆−(
𝑨𝑾𝒇
)𝜸𝟎𝑪𝑫𝑹
or
𝑹 =𝒎
𝑨𝜸𝟎𝑪𝑫∙ 𝐥𝐧 (
𝑽𝟎
𝑽𝒔)
A: fragment area (m2) Wf: fragment mass (kg) γ0: specific weight of air (kg/m3) CD: Drag coefficient (0.6)
MNGN 444 – Blast Damage Curves
Reference: P.Cooper, “Explosives Engineering”, Chapter 28, 1996.
Lung Damage:
Ear Damage: