RU2293665C1 - Fuel tank - Google Patents

Abstract

FIELD: aerospace engineering.

SUBSTANCE: invention relates to fuel tanks of spacecraft operating at zero-G and when changing from zero-G to G-loads. Proposed fuel tank has housing with intake and drain holes and cross partition hermetically fastened on housing walls. Partition is depressed in direction of intake hole, and hole with permeable element is made in its central part. According to invention, in peripheral part of said partition additional holes are made with fitted-in permeable elements. All permeable elements are made in form of capillary-porous elements of foamed metal based on corrosion-resistant metal or alloy. Capillary-porous element of central hole is arranged in cylindrical shell. The latter has solid base in lower part pointed to intake hole, and is provided with side ports at this base. Partition can be arranged in area of intake hole.

EFFECT: provision of stable repeated starting of engine plant of spacecraft at zero-G, reduced weight of fuel tank.

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Description

The invention relates to rocket and space technology, in particular to the fuel tanks of spacecraft (SC), operating in zero gravity and the transition from zero gravity to overloads.

A fuel tank is known from the patent literature, comprising a housing with an intake and drainage openings and a transverse partition with an opening with a permeable element concave towards the intake opening and tightly fixed to the walls of the tank housing (see, for example, England Patent No. 2109760, class B 64 G 1/40, F 02 K 9/50, op. 06/06/83).

As a result of overloads affecting the fuel under zero gravity conditions, for example, significant impulses of overloads arising from the operation of the orientation system, correction of the flight path, mechanical shocks (docking), etc., the integrity of the fuel is violated, and the fuel, moving throughout the fuel tank mixes with boost gas and approaches the intake opening with bubbles of boost gas, which adversely affects the operation of engines. To prevent the above, priority is given to the method of orientation of the fuel, based on the action of surface tension forces, the use of the capillary effect.

The main disadvantage of the known solution is that the fuel is held in the area of the intake opening and on permeable elements in the form of fine-mesh sieves or grids when exposed to alternating accelerations only in the absence of flow from the tank or at very low flow rates, in a small frequency range of efficient operation, as well as low mechanical strength, significant weight and dirt capacity. For example, grids generally do not hold vibration well due to the fact that they are not a volumetric structure and do not have a branched structure of an easily controlled pore space.

Effective grid operation is possible only at low frequencies (up to 30 Hz).

The objective of the present invention is to provide a fuel tank with a technical result in the form of increased reliability, i.e. supplying fuel from the fuel tank to the propulsion system without gas inclusions, which allows for stable multiple start-up of the propulsion system from zero gravity, reducing the weight of the fuel tank, and also expanding the arsenal of technical equipment for this purpose.

The solution to this problem lies in the fact that in the fuel tank containing a housing with intake and drainage holes and hermetically fixed to the walls of the tank body, a transverse bent concave towards the intake hole with a hole made in its central part with a permeable element, in accordance with the invention in the partition in its peripheral part, additional holes are made with permeable elements installed in them in the form of capillary-porous foam metal elements based on a corrosion-resistant metal alla or alloy, capillary-porous elements of the central hole are placed in a cylindrical shell, and the last in the lower part is equipped with a solid base and made at this base with side windows. In this case, the partition is preferably located in the area of the intake opening.

The invention is further explained in more detail using the drawings, in which Fig. 1 shows a fuel tank with one partition, Fig. 2 shows the filling of the tank by about 1/3 of the volume when the displacement of its center of mass under the action of lateral disturbing overloads is significant and dangerous, and The fuel tank is shown in two cases: without a partition and with a partition.

The fuel tank (Fig. 1) contains a housing 1 with an intake 2 and a drainage 3 holes and at least one (although there may be several) hermetically attached to the walls of the tank to prevent the flow of fuel in the wall areas of the partition 4 in the form of a truncated cone, dividing the internal cavity the tank into separate sections 5 and 6. In the central part of the partition 4 there is a foam metal 7 enclosed in a cylindrical shell 8. On the peripheral part of the side wall of the truncated cone (partitions), openings 9 are made for peripheral gas drainage Adduv from under the partition, still seeping (possibly) under the partition. The walls of the truncated cone (partitions) to reduce fuel under-intake are made almost continuous, with the exception of drainage holes 9, and inclined to the central axial part (made concave towards the bottom of the bottom or towards the intake hole). The lower base 10 of the cylindrical shell (the base facing the intake hole) is also solid to protect the foam metal from water hammer and fatigue stresses arising under the influence of alternating loads along the longitudinal axis of the spacecraft. The hole 11 in the cylindrical shell 8 serves for the penetration of fuel from the cavity 5 into the capillaries of the foam metal 7. The penetration of the fuel into the capillaries of the foam 7 from the cavity 6 occurs through one or more windows 12 of the shell 8. The fuel flow through the windows 12 is perpendicular to the longitudinal axis of the fuel tank. The holes on the periphery of the partition cone are also closed with foam metal.

The fuel tank with an internal partition works as follows.

Before starting the engine, the fuel tank at the start contains fuel (at the bottom of the tank) and boost gas (at the top of the tank). During the operation of the main engine, the overload that occurs creates a hydrostatic pressure of the fuel, much higher than the capillary pressure in the capillaries of the foam metal 7 located in the inner partition 4 of the fuel tank. Foam metal 7 does not retain the flow of fuel, and fuel penetrates from cavity 5 into cavity 6. At the time of the marching engine shutdown, fuel with significant kinetic energy tends to move into cavity 5 under the action of inertia forces from cavity 6. When a hydraulic shock arises as a result of this, part of the kinetic fuel energy is extinguished on the solid part of the partition and the solid lower base of the cylindrical shell of the partition, and the other part on the foam metal, because foam metal, having a specific mesh-cell volumetric structure of high capillary porosity, extinguishes a significant part of the fuel energy. Therefore, an insignificant part of the fuel that does not have large kinetic energy enters the cavity of the tank 5.

In zero gravity, small overloads from the operation of stabilization, orientation and correction engines act on the fuel tank, which cause a change in the position of the fuel mirror, which tends to be established perpendicular to the existing overloads. The magnitude of these overloads is several orders of magnitude less than the overloads along the axis of the spacecraft during the operation of the main engine. The hydrostatic pressure resulting from such overloads is less than the capillary pressure in the capillaries of the foam metal 7, and the permeable part of the baffle holds the fuel, preventing the mirror from being installed perpendicular to the acting overloads, thereby maintaining the center of mass of the fuel tank on the longitudinal axis of the spacecraft and ensuring normal (without gas bubbles) ) fuel intake for control engines.

As a corrosion-resistant metal or alloy for the manufacture of foam metal, taking into account the need for low specific gravity, high rigidity and corrosion resistance, it is recommended to use Al, nichrome, corrosion-resistant steel.

Thus, the technical result is achieved as a result of the fact that:

- there are excellent capillary properties due to the uniformity of the strictly regulated mesh-cellular three-dimensional structure of the pore space, its volume, the presence of channel porosity, high porosity (95%), which provides a low specific gravity, low hydraulic resistance, large capacity, and an increased pore tortuosity coefficient, increasing with porosity over 90%. Moreover, the porosity is uniform in volume and is easily controlled;

- high corrosion resistance, high rigidity with low specific gravity.

Having the volume of the pore structure, the complex configuration of the pore channels, such as their narrowing, expansion, affecting capillary pressure, change of direction and branching, the presence of sharp edges, foam metal breaks the fuel flow that occurs during the transition from zero gravity to overloads into microflows. In this case, a significant dissipation of the energy of the moving liquid component occurs. The high surface density of capillary channels, foam metal (due to 95% of the volume of voids) positively affects the dissipation of fuel energy. The kinetic energy of the fuel is spent on overcoming the capillary forces arising in the capillaries of the foam metal. As a result of this, the hydrodynamic effect of fuel on the tank walls is reduced, decreasing the displacement of the center of mass of the fuel tank from the longitudinal axis of the spacecraft. Under zero gravity conditions, the foam-metal part of the tank’s partition, due to the capillary effect, does not allow fuel to move throughout the entire volume of the fuel tank and shift the center of mass from the longitudinal axis of the spacecraft.

Claims (2)

1. A fuel tank, comprising a housing with an intake and drainage holes and a hermetically sealed transverse partition wall concave toward the intake opening with an opening with a permeable element in its central part, characterized in that additional openings are made in the peripheral part of the partition with installed they are permeable elements, all permeable elements are made in the form of capillary-porous elements of foam metal based on a corrosion-resistant metal or alloy, capillaries Jarno-porous member disposed in the central opening of the cylindrical shell, and the latter in the lower part is provided with a solid base facing to the intake hole, and is formed at the base of the side windows. 2. The fuel tank according to claim 1, characterized in that the partition is located in the area of the intake opening.

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