
47Physical Foundation of Interior Ballistics
Problem 12
M15 propellant was tested in a strand burner to determine the linear burning rate. The
average pressure evolved was 10,000 psi. If the burning exponent, α, was known to be 0.693
and the pressure coefcient, β, was known to be 0.00330 in./s/psi
0.693
. Determine the aver-
age linear burning rate, B in inch per second.
Answer: Bp() .=
1 952
in.
Problem 13
Derive the functional form of ϕ in terms of f for a ake propellant. Assume cylindrical
geometry.
Hint: Flake propellant consists of grains that have thicknesses much smaller than any
other characteristic dimension.
Answer: ϕ(t) = 1 − f
Pro