The Nozzleless Performance Program, NPP97^TM, is designed to compute the performance of nozzleless rocket motors.  The motor structural dynamics and statics, grain design and ballistics including ignition transients are all modeled within the NPP code.

The primary objective of the NPP was to develop and demonstrate a practical computer program capable of reliable a-priori performance prediction of nozzleless solid rocket motor instantaneous thrust, pressure, and burn time to within +/- 5 percent and total impulse and delivered specific impulse to within +/- 2 percent.

The technical elements included within the NPP are:

• Gas Dynamics
• Ignition thrust and pressure spikes
• Tail off
• Choke Conditions
• Arbitrary Grain Surface Shape during Burn Back
• Two Dimensional and multiphase flow effects
• Propellant Burn Rate
• Erosive Burning
• Radiation Effects
• Transient Effects
• Propellant Grain Deflection
• Structural interactions as a function of internal ballistics, variable physical properties and viscoelastic behavior, dynamic response of material properties
• Combustion Efficiency
• Metalized and Non-Metalized Propellants