| || Partial Burn Laws in Propellant Erosive Burning
Author : Zenin, A.A. ;Finjakov, S.V.
Source : Defence Science Journal ; Vol:49(2) ; 1999 ; pp 159-168
Subject : 662.3 Propellants;66 Chemical Technology
Keywords : Composite propellants ;Partial burn law
Abstract : "Experimental and computer methods were developed for investigating the combustion phenomena in the propellants which burn in streams of hot gas flowing along the burn surfaces of the propellants. The experimental investigations allowed establishment of different dependencies for erosive burning. Computer solutions of the problem for double-base (DB) propellants showed a good agreement with the experimental results. The suggested variant of modified theory considers the change of heat release in solids, the real burn surface roughness, the nonisothermality of boundary layer and the effect of gas mass blow from the propellant burn surface into the gas stream. This modified theory was used for studying burn laws at 30-1000 atm and up to gas stream sound velocities for different DB propellants. It was found that gas stream leads to splitting of the propellant burn laws, m = bp/sup v/. Pressure power (v), in this case depends on gas stream velocity (W), diameter of the propellant tube canal (d) and gas stream temperature (T/sub w/). It is because of this that these burn laws were named partial burn laws. They have the form (m = bp/sup w(omega)/) w,d,T/sub w/ -const. The dependencies w(omega) = f(w,d,T/sub w/) were obtained by the modified theory. It was found that omega values mainly decrease when pressure increases beginning from ~200 to 400 atm and they can decrease up to w(omega) = 0,1- 0,3. Similar results can be obtained for composite propellants."