Analysis of External Ballistics for a Projectile of Caliber 155 MM
Palavras-chave:Projectile, angle of attack, stability, semispherical profile, center of gravity
ResumoThe objective of this thesis is to propose a geometry for a projectile to firefighting. The finite volume code STAR − CCM+® is used to calculate forces and moments acting on the projectile and a code is created in MATHEMATICA® to define the characteristics of the trajectory. The PRODAS® is used to verify and validate the models implemented. Initially, the procedure adopted was to create an entire methodology for an existing ammunition that would allow be verified and validated with the available literature. An extensive aerodynamic characterization has been done through CFD in order to establish the projectile forces and moments behavior and thus feed the further 6 DOF computation. It was concluded that the locking strap, the guiding strap and the Coriolis drift were negligible compared to the results obtained. The implementation of angle of attack came to influence the range and stability of the projectile. In the following phase six different geometries were tested, varying the lenght and the nose. Set up for this projectile an initial velocity of 100 m/s, 10 kg, concluding that the total length would be 697.1 mm and semispherical profile with the capacity to transport 7.5 dm3 inside. Wind tests were conducted to evaluate the stability in flight, and the software and analysis process developed in this work are available, being a contribution to the project FIREND.