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Public Domain Aeronautical Software (PDAS)  

The primary function of this computer program is the calculation of the divergence dynamic pressure and associated divergence modal characteristics of unguided, slender-body, multistage launch vehicles. The divergence dynamic pressure is obtained as the non-trivial solution to a homogeneous stability equation using matrix recurrence techniques. Provision is made for modulating the distributed lift curve coefficient slope function and the stiffness function. The program also includes an option for calculating a generalized static margin which approximates the degeneration in rigid-body static margin due to aeroelasticity effects. Evaluated equations are also programmed to allow for the exclusion of the effect of aerodynamic crossflow resulting from vehicle angular velocities if desired. Other physical and aerodynamic properties calculated include total mass, center of mass, moments of inertia in pitch about the reference station, total aerodynamic lift curve slope, static aerodynamic center of pressure, rigid body static margin, and short period frequency. Input to the program is via the Fortran NAMELIST option with output printed. ( NASA Langley Research Center )

This program was released by NASA through COSMIC as LAR-12004. The italicized text above is from the official NASA release.

PDAS home > Contents > Diverge
Public Domain Aeronautical Software (PDAS)