Determination of pendulous projectile trajectories

A new simplified system of equations of motion was established allowing quick computation of the trajectories of pendulous projectiles. The essential characteristic of this system is that it is limited to axisymmetric projectiles, excluding, therefore, the necessity of determining the angle of roll. The related computer program offers the possibility of entering the aerodynamic coefficients both as function of the Mach number and as function of the angle of incidence. Thus, it is also suited to the computation of trajectories presenting very large angles of pendulation. The choice of appropriate reference systems and variables allowed numerical determination of the maximum quantity of motion using a normal capacity. A FORTRAN program was written allowing the pendulum motion of projectiles in the initial portion of the trajectory to be computed in a few minutes, using a computer of the IBM 370-135 type. Even for maximum flight times the determination of entire trajectories will not exceed 1 hour of computation.