
94 Ballistics: Theory and Design of Guns and Ammunition
1. Come up with the equation for the web fraction, f, as a function of time.
Answer: f = (1 − 823.29t) [%]
2. For a sphere, the fraction of propellant burnt has the functional form ϕ = 1 − f
3
,
write this in terms of time and ϕ.
Answer: ϕ = 2,470t − 2,033,419t
2
+ 558,031,251t
3
3. Determine how long it will take the propellant to burn halfway through and all
the way through.
Answer: Time to burn through halfway is 0.6 ms
4. Using the Noble–Abel equation of state, determine the pressure in the vessel when
half of the propellant is burnt and when all of the propellant is burnt. Note that ...