Paper and board. Determination of air permeance and air resistance (medium range)

The magnitudes of the kinematic parameters of projectiles motion in the air depends on deterministic (form of projectile, its mass, temperature of air and charge, atmospheric pressure, derivation) and nondeterministic (muzzle velocity, magnitude and direction of wind velocity) values. During the projectile movement, its weight and frontal air resistance force have a determining influence on its dynamics. In the article it is investigated proposed by authors the mathematical model of determination of the functional dependence of the magnitude of the frontal air resistance force of the projectile’s motion on its velocity, mass and caliber, geometric characteristics, temperature and density of air, atmospheric pressure, sound speed in air. Since the trajectory of movement of the BM1 projectile released from the T-12 (MT-12) is canopy, it is assumed that during the projectile’s flight the air temperature and atmospheric pressure are unchanged and equal to their value at the point of the gun.

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Note on the trajectories of rifled projectiles with various shapes of head

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1908.0044 ◽

1908 ◽

Vol 80 (541) ◽

pp. 519-529

Keyword(s):

Approximate Formula ◽

Air Resistance

In two previous papers I gave an approximate formula for the determination of the range and elevation of a pointed rifle projectile, of which the head was an ogive with a radius of two diameters. This approximation agreed so closely with the results obtained in practice that it seemed worth while to ascertain whether the same type of formula would not apply equally well to other shapes of head. For this purpose I have made the experiments which will be presently described. In order to explain clearly what the exact points to be decided were, I will briefly restate the origin of the formulæ given in the former papers. The results of all the experiments made on air resistance at high velocities agree in giving a curve of retardation in terms of velocity of the form shown in Diagram I.

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