Shadow scheme with selective range of photoregistration in aerodynamic tests

Abstract

The classical straight-cut registration scheme has a high resolution and the absence of distortions associated with the use of optics. The principal drawback that does not allow the use of this scheme in the field – susceptibility to background radiation accompanying the experiment. Number of recorded processes are characterized by relatively small size of the objects being thrown, for example, in the problem of modeling the impact of space debris with given screens or in the problem of modeling the emergency expansion of fragments of the active material. Resolution of x-rays is insufficient to render such particles, and their hypersonic speed and the corresponding ionization of the air result in the exposure of photographic film in an open straight-cut scheme. Additional background highlights in such experiments are the emission of muzzle exhaust in the case of use for dispersal of ballistic barrel systems or the glow of the explosion products in the case of detonation accelerating devices. Meanwhile, opportunities of straight-cut scheme can be expanded by spending experience in the twilight time of the day and protected from background radiation, for example, by raccord as a filter of large area. The paper describes a shadow scheme of photo registration, which includes a point light source and a wide-format film with a protective filter. The result of application of this scheme in aerodynamic tests accompanied by intense background illumination is presented.