The APMOD software provides a means for the motor designer to easily set up the propellant grain geometry, compute the burning surface history, and perform lumped-parameter transient analysis using closed-loop controls. The relationship between motor pressure and thrust is computed using the CFD-ACE flow solver, which is also tightly coupled to the APMOD system.

Key features for the software include:

• Grain Design - The GUI features a number of pre-defined geometry options, making the setup of complicated grain geometries quick and easy
• Ballistics - The ballistics modules from the '97 SPP code have been integrated in a stand-alone mode to compute the burning surface history
• Geometry Definition - The available geometry paradigms make the definition of the pintle and throat geometry as simple as specifying a few key parameters
• Grid Generation - The geometry definition is automatically converted to boundary conditions for a stand-alone elliptic grid generation program that creates a single-domain computational mesh for the CFD solver
• Performance - The GUI reduces the task of setting up an ACE input file to the specification of a few key parameters. The code is then run in the background and the output monitored
• Controls - The GUI allows the user to perform transient simulations of the motor behavior with a variety of controls strategies, including closed-loop control on motor thrust