Search

A method and system for contactless measurement of the velocity of flight of a thrown body over a measuring base in an air atmosphere and for the actuation of a recording apparatus by the signal formed as a result of the passage of the body through a measuring section are presented. The method proposed is based on the formation of normalized pulses of positive polarity for the synchronization of the activation of a recording apparatus by a definite coordinate of a body thrown. Results of calculation and experimental investigations of variable reluctance pickups in tests of high-velocity ballistic flights are presented. Relations allowing one to estimate the dependence of the magnetic induction in the core of a variable reluctance pickup on the value of the air gap between a magnet and the pickup are presented.

Experimental data on the motion parameters of a steel spherical impactor whose diameter is 13.5 mm and which moves in a sandy medium at a velocity of 1470 m/s are presented. Induction sensors and the PIV (particle image velocimetry) method are used to record the impactor motion near a sandy obstacle and in a sandy medium, thereby allowing one to visualize a surface wave via high-speed video recording of the sand surface. The values of the parameters characterizing the impactor motion in the sandy medium and the surface wave propagation are obtained.

This paper describes the design of a gas-discharge emitter, which is implemented by limiting the spread of the discharge in a narrow gap between two transparent equidistant surfaces, with air as the working gas with a peak brightness of 6.2 Msb, a luminous body of 18 cm2 (at a discharge energy of 75 J), and a halfwidth duration of ~2 μs. This scheme can be used to solve a wide class of problems, for example, those related to photogrammetric measurements in aeroballistic tests, as well as when creating pulsed loads when detonation is initiated in an extended layer of a photosensitive energy-saturated material.

Launching and control of pyrotechnical systems at a specified coordinate is among the most complicated problems in the tests at a missile track. A method for launching and a corresponding device are proposed for activation of pyrothechnical systems of missile trains boosting along an ejection path to hypersonic velocities with ejection of an object to free flight. The method is based on generation of current pulses for activation of pyrotechnical systems of the moving stages of a missile train using inductive sensors. The principle can also be used for implementation of a noncontact method for activation of recording systems and a device for measurement of the mean velocity of an ejected object in continuous media. The method is based on the generation of starting signals (positive rectangular pulses) for activation of recording equipment with matching relative to the specified coordinate and measurement of the velocity of the ejected object at the moment when it passes through the measurement cross section. Methods for activation of recording systems and results of hydrodynamic and terradynamic experiments are presented.

Shock-wave loading of transparent objects is studied with the aid of a theoretical method based on numerical simulation on a 3D regular mesh using an explicit solver in the Euler–Lagrange connected formulation and an experimental method using shadow photography and shadow background technique.

Means of reducing the transverse load on a projectile accelerating in the barrel of a light-gas gun are considered.

We analyze the estimate of the drag coefficient error obtained in aeroballistic experiment. Technical solutions, schemes, and devices for increasing the informative character of the experiment and reducing the error in the drag coefficient determination are proposed.