User experience with interim version SPP

The problems and successes encountered using the interim version SPP were evaluated. The major problems in matching measured data are: (1) particle size model, to match the wide range of full scale motor firing, a slight change had to be made; (2) erosion loss calculation; the loss using the initial area ratio minus the average area ratio from ODE proved more successful; (3) particle impingement loss, the program is unable to handle the impingement loss for high expansion ratio nozzles with high impingement present. It is found that the current interim version with the changes made in particle size and erosion calculation is successful in accurately predicting the 21 motor data base with the exception of the high impingement nozzle.