RU2285881C1 - Ballistic installation and method for making of fire shot from it - Google Patents

Abstract

FIELD: best equipment, mainly used for an aeroballistic test of light vehicle models.

SUBSTANCE: the ballistic installation has a high-pressure chamber, barrel with a bottom plate installed in it with an aerodynamic model, and a working diaphragm positioned on the muzzle end of the barrel. Ducts for connection to the vacuum system and the gas filling system are made in the wall of the barrel terminal section. A muzzle cap is fastened on the muzzle end, it consists of successively installed working diaphragm made of an easily destructible material, separated from it by a separating ring of the process diaphragm of a high-strength material, sealing ring and a clamping ring fastened on the barrel, opening with a conic expansion towards the process diaphragm made in it. The inside diameters of the separating, sealing and lamping rings are larger than the diameter of the barrel duct. Provision is made for arrangement of a muzzle cap on the barrel end, filling of the barrel before the bottom plate with the model after its vacuum processing by an inert light gas and removal of the process diaphragm.

EFFECT: enhanced information content of aeroballistic experiments.

2 cl, 2 dwg

Description

The invention relates to a testing technique. The primary area of use is aeroballistic testing of aircraft models.

Aeroballistic tests of aircraft models are carried out by the method of shooting them from barrel ballistic installations into the undisturbed air of the test track, the formulation of which is set forth in the monograph by S. I. Gerasimov, Yu. I. Faykov and S. A. Kholin “Cumulative light sources”, RFNC- VNIIEF, Sarov, 2002, pp. 167-168, Fig. 3.66. To determine the spatial position of the aerodynamic model by means of multi-angle photography, a heat-resistant paint and varnish coating with a system of reference marks is applied to its lateral surface. During acceleration of the model installed in the lead tray, an air “plug” is formed in front of the model in the barrel of the ballistic installation, in which, as calculations have shown, at the model’s muzzle velocity of ≈2000 m / s, the temperature can reach ≈2600 K, and the pressure can reach ≈ 9 MPa. When the model interacts with such an air “plug”, the heat-resistant paintwork burns out and the reference system is damaged (see ibid., P.176 and 177, Fig. 3.80), as a result of which the error increases, and sometimes it becomes impossible to determine the spatial position of the model , and therefore its aerodynamic characteristics.

It is known "Dispositif pour accelerer des charges utiles jusqu'a la vitesse du son et audela" (a device for accelerating payloads to sound speeds and above), patent FR No. 2309827 IPC F 41 F 1/00, publ. 11/26/1976, selected as a prototype. The device for accelerating the useful masses comprises a high-pressure chamber, a barrel (acceleration section), a stopping device, a useful mass accelerated along the barrel, and a working diaphragm separating the vacuumized acceleration section from the stopping section. The disadvantage of this device is the fact that in the case of acceleration of the model in an evacuated barrel due to the absence of an air "plug", the model interacts with the diaphragm, as a result of which the paintwork will also be damaged, since the diaphragm designed to seal the barrel and is capable of to withstand a pressure drop of 0.1 MPa, should be made of high-strength film.

A known method of producing a shot from one- and two-stage ballistic installations intended for throwing aerodynamic models is described in the article "Aeroballistic installation - a tool for modern experimental hypersonic aerodynamics", a collection of "Theoretical and experimental studies of hypersonic flows around bodies and in tracks" edited by G. .G. Cherny and S.Yu. Chernyavsky, Moscow University Press, 1979, pp. 12-13, selected as a prototype. The method includes a sequence of operations common to both types of ballistic installations, which consists of installing a model pallet in the barrel, evacuating the barrel in front of the model pallet, creating a throwing gas pressure in the high-pressure chamber, and firing a shot. The disadvantage of this method is that it involves a shot by a model into an evacuated route and does not provide for aeroballistic tests in an undisturbed air environment, which, of course, limits the possibilities of an aeroballistic experiment.

The technical problem to be solved is the creation of a ballistic installation and a method of firing a shot from it, ensuring the safety of the reference system applied to the surface of the tested aerodynamic models when staging aeroballistic experiments in an undisturbed air environment.

The expected technical result is to increase the information content of aeroballistic experiments.

The technical result is achieved through the use of a ballistic installation containing a high-pressure chamber, a barrel with a pallet installed in it with an aerodynamic model and a working diaphragm located on the muzzle of the barrel. In the wall of the final section of the barrel, channels are made for connection with a vacuum system and a gas filling system. A muzzle device is fixed on the barrel cut, consisting of a sequentially installed working diaphragm made of easily destructible material, separated from it by a dividing ring of the technological diaphragm made of durable material, a sealing ring and a clamping ring fixed to the barrel, the hole in which is made with a conical extension towards the technological diaphragm. The inner diameters of the separation, sealing and pressure rings are made larger than the diameter of the bore.

The technical result is also achieved through the application of the method of firing a shot from the ballistic installation presented above, which consists in installing a pallet with an aerodynamic model in its barrel, evacuating the barrel in front of the pallet with the model, creating the pressure of the throwing gas in the high-pressure chamber and firing, when placed before a shot at a section of the barrel of a muzzle device containing a working one made of easily destructible material and a technological one made of durable material of the diaphragm, filling the volume of the barrel in front of the pallet with the model after it has been evacuated with an inert light gas and removing the technological diaphragm.

A comparative analysis of the proposed ballistic installation and its prototype shows that the proposed solution is characterized by a combination of the following design features:

- in the wall of the final section of the barrel a channel is made for connection with a vacuum system;

- in the wall of the final section of the barrel a channel is made for connection with a gas filling system;

- the muzzle device contains a working diaphragm made of easily destructible material;

- the muzzle device contains a technological diaphragm made of durable material;

- the working diaphragm is separated from the technological diaphragm by a dividing ring;

- the muzzle device contains a sealing ring;

- the muzzle device contains a clamping ring fixed to the barrel;

- in the clamping ring a hole is made with a conical extension towards the technological diaphragm;

- the inner diameters of the separation, sealing and pressure rings are made larger than the diameter of the bore.

The execution in the wall of the final section of the barrel of the channel for connection with a vacuum system ensures the evacuation of the volume of the barrel in front of the pallet with an aerodynamic model.

The execution in the wall of the final section of the barrel of the channel for connection with the gas filling system provides filling of the barrel before the pallet with the aerodynamic model of inert light gas.

The implementation of the working diaphragm from easily destructible material is a prerequisite for ensuring its rupture in the process of firing a gas "plug" formed in front of the model until the moment when the model can touch its diaphragm nose.

The implementation of a technological diaphragm made of durable material is a prerequisite for eliminating the rupture of the working diaphragm from atmospheric pressure when evacuating the barrel or in case of unauthorized exceeding the required pressure when filling the barrel with an inert light gas.

Separation of the working diaphragm from the technological separation ring is necessary to exclude the possibility of damage to the working diaphragm when removing the technological diaphragm by cutting it along the contour.

The presence of a sealing ring is due to the need to seal the barrel.

The presence of a clamping ring is necessary to compress the package from the working and technological diaphragms along the sealing contour.

The opening in the clamping ring with a conical extension towards the technological diaphragm facilitates the removal of the technological diaphragm by cutting it along the contour without damaging the working diaphragm.

The implementation of the internal diameters of the dividing, sealing and pressure rings larger than the diameter of the barrel eliminates the impact of the pallet on the ring when it exits the barrel.

A comparative analysis of the proposed method of a shot from a ballistic installation and its prototype shows that the proposed solution is characterized by a combination of the following features:

- before firing into the shear, the barrel of the ballistic installation is fixed a muzzle device containing a diaphragm working from easily destructible material and a technological diaphragm made of durable material installed after it;

- after evacuation, the barrel is filled in front of the sump with the aerodynamic model with an inert light gas;

- remove the technological diaphragm.

Securing a barrel-mounted ballistic installation of a muzzle device containing a diaphragm working from easily destructible material and a technological diaphragm installed after it from durable material solves the problem of evacuating the barrel and then filling it with an inert light gas.

Filling the barrel in front of the sump with the aerodynamic model with inert light gas allows you to lower the temperature in the gas "plug" and to prevent the burning of heat-resistant paintwork on the surface of the aerodynamic model.

Removing a technological diaphragm made of durable material and, accordingly, bursting at a significantly higher pressure than the working diaphragm, eliminates contact with it of the aerodynamic model and, as a result, damage to the reference system deposited on the surface of the model.

Figure 1 shows a diagram of the proposed ballistic installation and method of producing a shot from it, figure 2 - design of the muzzle device.

The ballistic installation contains a high-pressure chamber 1, a barrel 2 with a pallet 3 installed in it with an aerodynamic model 4. In the wall of the final section of the barrel 2, channels are made: 5 for connecting to a vacuum system and 6 for gas filling system. A muzzle device 7 is fixed on the cut of the barrel 2, consisting of a sequentially installed working diaphragm 8 made of easily destructible material, separated from it by a dividing ring 9 of the technological diaphragm 10 made of durable material, a sealing ring 11 and a clamping ring 12 fixed to the barrel 2, the hole 13 in which made with a conical extension 14 towards the technological diaphragm 10. The inner diameters of the separation 9, sealing 11 and pressure 12 rings are made larger than the diameter of the barrel 2.

The operation of the ballistic installation and the method of producing a shot from it for conducting an aeroballistic experiment are as follows.

A muzzle device 7 is installed on a section of the barrel 2 of the ballistic installation, consisting of a sequentially placed working diaphragm 8 made of easily destructible material separated from it by a dividing ring 9 of the technological diaphragm 10 made of durable material, a sealing ring 11 and a pressure ring 12. Channels 5 and 6 made in the wall of the final section of the barrel 2, by means of fittings 15 and 16 and pipelines 17 and 18 are connected to a vacuum pump 19 and a cylinder 20 with an inert light gas. A pallet 3 with an aerodynamic model 4 is placed in the breech of the barrel, on which a system of reference marks 21 is applied using a heat-resistant paint and varnish coating. Next, to evacuate air from the barrel 2, it is evacuated before the pallet 3 with model 4. Since the burst pressure of the working diaphragm 8, made of easily destructible material, should be lower than the atmospheric pressure, the use of a technological diaphragm 10 of durable material protects the working diaphragm 8 from destruction when the barrel is evacuated. This is achieved by equalizing the pressure on both sides of the working diaphragm 8 due to the fact that during the evacuation process, the working diaphragm 8 bends into the inside of the barrel 2, in connection with which the volume between the working 8 and technological 10 diaphragms increases and the pressure in it decreases. After completion of evacuation, the barrel 2 in front of the pallet 3 with model 4 is filled from the cylinder 20 with an inert light gas, for example helium. Next, the technological diaphragm 10 is cut along the contour, and in order to prevent damage to the working diaphragm 8, the hole 13 in the pressure ring 12 is made with a conical extension 14 towards the technological diaphragm 10. A pressure is created in the high-pressure chamber 1 of the ballistic installation, and the pan 3 s aerodynamic model 4 under the influence of the throwing gas is accelerated along the bore of the barrel 2. The gas "plug" 22 formed in front of the pallet 3 with model 4 destroys the working diaphragm 8 until the moment when model 4 can touch its nozzle aperture. Moreover, the calculations showed that replacing air with helium at a model velocity at the muzzle end of ≈2000 m / s makes it possible to reduce the temperature in the helium plug 22 in front of the model to ≈ 850 K and the pressure to ≈1.7 MPa. This ensures the preservation of the paintwork with the system of fixed marks 21 on the surface of the tested aerodynamic model. The implementation of the inner diameters of the separation 9, the sealing 11 and the pressure 12 rings larger than the diameter of the bore 2 provides unhindered exit of the pallet with the model from the barrel of the ballistic installation.

The proposed ballistic installation and method for producing a shot from it have significant positive properties compared to prototypes, which can increase the information content of aeroballistic experiments when they are set up in an unperturbed air environment by ensuring the safety of the reference system applied to the surface of the tested aerodynamic model.

The proposed technical solutions passed an experimental test, which confirmed their performance.

Claims (2)

1. A ballistic installation containing a high-pressure chamber, a barrel with an installed pallet with an aerodynamic model and a working diaphragm located on the muzzle of the barrel, characterized in that the channels for connecting to a vacuum system and gas filling system are made in the wall of the final section of the barrel, a muzzle device is fixed on the cut of the barrel, consisting of a sequentially installed working diaphragm made of easily destructible material, separated from it by a dividing ring of technological diaphragms of a durable material, and a sealing ring mounted on the stem of the tightening ring, wherein the aperture formed with a conical extension towards the diaphragm process, the inner diameters of the spacer, sealing and clamping ring are made larger bore diameter. 2. A method of producing a shot from a ballistic installation, including installing a pallet with an aerodynamic model in its barrel, evacuating the barrel in front of the pallet with the model, creating a throwing gas pressure in the high-pressure chamber, and firing a shot, characterized in that a muzzle device is placed on the barrel section before evacuation containing sequentially installed working of easily destructible material and technological of durable material of the diaphragm, fill the barrel in front of the pallet with the model after it akuumirovaniya easy inert gas and removed technological diaphragm.

Images