Method for determination of air resistance (Gurley) of paper and board

1980 ◽  
Keyword(s):  
Air Resistance

scholarly journals ЗОВНІШНЯ БАЛІСТИКА СНАРЯДУ БМ1 ВИПУЩЕНОГО З Т-12 (МТ-12)

World Science ◽  
2020 ◽  
Vol 1 (1(53)) ◽  
pp. 23-29
Author(s):  
Величко Лев Дмитрович ◽  
Горчинський Ігор Володимирович ◽  
Сорокатий Микола Іванович
Keyword(s):  
Atmospheric Pressure ◽  
Sound Speed ◽  
Functional Dependence ◽  
Resistance Force ◽  
Kinematic Parameters ◽  
Muzzle Velocity ◽  
Velocity Magnitude ◽  
Air Resistance ◽  
The Mathematical Model

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.

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

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.

scholarly journals MODIFICATION OF WIND TUNNELS IN THE AUTOMOTIVE INDUSTRY AND THE RESULTS OF DETERMINATION OF COMPONENT AIR RESISTANCE

2018 ◽  
Vol 3 (11) ◽  
pp. 114-121
Author(s):  
Исмаил Мустафаев ◽  
Ismail Mustafaev ◽  
Елена Чубенко ◽  
Elena Chubenko
Keyword(s):  
Automotive Industry ◽  
Wind Tunnels ◽  
Air Resistance

A new absolute determination of the acceleration due to gravity at the National Physical Laboratory, England

1967 ◽  
Vol 261 (1120) ◽  
pp. 211-252 ◽  
Keyword(s):  
National Physical Laboratory ◽  
Atomic Unit ◽  
Time Intervals ◽  
Gravity Station ◽  
Absolute Determination ◽  
Physical Laboratory ◽  
Air Resistance ◽  
Definition Of ◽  
First Time

A new absolute determination of the acceleration due to gravity at the National Physical Laboratory has been made by timing the symmetrical free motion of a body moving under the attraction of gravity; it is the first time this method has been used. The moving body was a glass ball and it was timed at its passage across two horizontal planes by the flashes of light that it produced when it passed between two horizontal slits which served to define each plane optically, the ball focusing light from one of the slits, which was illuminated, upon the other slit which had a photomultiplier placed behind it. The separation of the two planes defined by the pairs of slits was measured interferometrically and referred directly to the international wavelength definition of the metre, while the time intervals were measured in terms of the atomic unit of time scale A l. The value of gravity as reduced to the British Fundamental Gravity Station in the N. P. L. is 981 181.75 mgal, s.d. 0.13 mgal (1 mgal = 10 -5 m/s 2 ). Systematic errors, are believed to be very small; this is particularly true of the error due to air resistance. The main contribution to the observed scatter of the results comes from microseismic disturbances. The new result is 1.4 mgal less than that obtained at the fundamental station by J. S. Clark (1939) using a reversible pendulum . It is very close to the mean of a number of recent absolute determinations by other methods, but this may not be very significant because the uncertainties of those determinations and of the comparisons between the sites at which they were made and the present site are not less than 5 times the standard deviation of the new result.

scholarly journals Fixation of Tarpaulin Sheet of Platform HDV and its Impact to Air Resistance

2018 ◽  
Vol 14 (1) ◽  
pp. 6-10
Author(s):  
Tomáš Skrúcaný ◽  
Martin Vojtek ◽  
Gabriel Suchter
Keyword(s):  
Aerodynamic Drag ◽  
Technical Standard ◽  
Air Resistance ◽  
Velocity Changes ◽  
Vehicle Deceleration ◽  
Engine Power

Abstract This paper due to determine an aerodynamic drag for different ways of tarpaulin fixation, specifically tarpaulin tension and disposition on platform-type body of a HDV. More positions of the tarpaulin were investigated. Determination of the resistances was done by coast down test of the vehicle according to Slovakian technical standard (STN). The aerodynamic drag was calculated from actual vehicle deceleration during the coast down test from the actual velocity changes. The vehicle actual velocity was measured by GPS logging device. Results are values of resistance, which affect the vehicle and their sum represents the actual engine power needed for vehicles driving.

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