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DOI: https://doi.org/10.37129/2313-7509.2024.21.40-46

INFLUENCE OF THE ACCURACY OF DETERMINING THE AERODYNAMIC COEFFICIENTS OF THE LIFTING FORCE ON THE FLIGHT DISTANCE OF THE PROJECTILE

Abstract

An important component of the vector of aerodynamic forces is the lifting force of the projectile, which is formed by the surface of the projectile body, depends on the size of the nutation angle, its shape and significantly affects its flight dynamics. The lifting force is expressed through its dimensionless linear and quadratic aerodynamic coefficients, respectively, the theoretical and practical study of the lifting force consists in the experimental study of its aerodynamic coefficients at different projectile flight speeds. To evaluate the influence of aerodynamic coefficients of the lifting force on the flight range of projectile, the difference method is used, which consists in solving the system of differential equations of the spatial motion of the projectile so that, by changing the value of the aerodynamic coefficient, the change in the value of the flight range is obtained. Numerical modeling of the dependence of the flight range of the 155-mm high-explosive projectile Assegai M2000 on the change in the value of the linear and quadratic aerodynamic coefficients of the projectile’s lifting force by 1% was carried out. It is shown that the largest error in the flight range of the projectile is introduced by the linear coefficient of the lifting force when firing at the maximum charge, and the smallest, respectively, at the minimum charge. So, when firing at the maximum charge, the errors reach a value of 0.3% D, respectively the smallest, at minimum charge – 0.005% D. In addition, the simulation results showed that the influence of the quadratic coefficient of lifting force of the projectile has 1-3 orders of magnitude smaller values compared to the linear one. The obtained results make it possible to estimate the required accuracy of determining the aerodynamic coefficients of the lifting force under different firing conditions of artillery systems.

Keywords: artillery projectile, lifting force, aerodynamic coefficient, nonlinearity, firing range, relative error, difference method.

FULL TEXT  (in Ukrainian)

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