Air Resistance Coefficient and Flight Speed Characteristics of Spherical Fragments

Focusing on the lethality accurate assessment and explosion safety distance calculation, the air resistance coefficient and flight speed at different distance were studied. The air resistance coefficient of ϕ6 mm and ϕ11 mm spherical fragments can be gained through experiment, when Mach number range from 0.7 to 5.3. The variation relationship of air resistance coefficient and air resistance with Mach number lower than 6.0 have been studied by Fluent simulation. The results show that the air resistance coefficient is independent of spherical fragments, but increased first and reached the peak value at the Mach number of 1.2, then decreased with the further increasing of Mach number. The air resistance increases rapidly around the Mach number of 0.8, wherein the pressure resistance accounts was more than 90% and the proportion of friction resistance was less than 10%. A model for calculating flight distance of spherical fragments with Mach number lower than 6.0 has been established, of which its reliability has been verified.