1. /D=0.1 ID=0.1 G = -0.0332+0.1694(?/i0 Ifor F/Fo
2. D=O.1 bracketing values using Equation 13. Linear interpolation is next used to obtain the ?/E, ID=O.1 value at the actual temperature, and Equations 10-12 are then used to correct for D f 0.1 ft. (If the calculated value of E/? is less than 1.0, it is set equal to unity.) Finally, the erosive ratio and the base burn rate are multiplied together to give the total steady-state burning rate.
3. Grain port diameter (ft) the solid propellant coupled with a simple gas-phase heat feedback relationship (which was also used in the P-dot calculations for consistency) for heat feedback fluxes ramping upward i n time at rates corresponding t o pressurization rates of 2500 t o 17000 atmospheres per second. Results of predicted burn rate versus time for all three options are shown for two typical cases in Figs. 7 and 8. These results confirm that Option A is unacceptable, but indicate that the P-dot procedure yields satisfactory agreement with the rigorous approach under the pressurization conditions examined, representative of nozzleless motor ignition transients. Accordingly, the much simpler P-dot approach was selected for use in NPP for correction of the quasi-steadystate burn rate for transient effects associated with time-variant pressure and crossflow velocity via:
4. Kinetic distance (Fig. 1) associated with OIF gas reaction (cm) Propellant burning m a s flux (gm/cm 2 sec i n Eqn. 1-3, Ibm/ft 2 sec in Eqn. 4,6) Temperature profile constant appearing i n P-dot equation