RU2469925C1 - Liquid-propellant jet engine thrust unit - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed unit comprises bearing frame, rotary combustion chamber with nozzle, bottom protection with moving and fixed shields and clearance there between. Bottom protection is arranged nearby nozzle critical diameter and with clearance between shields at diameter smaller than nozzle OD. Fixed shield surface bulges outward while shield thickness increases toward nozzle. Bottom protection on nozzle side has surface with higher reflection of heat radiation.

EFFECT: higher reliability.

4 cl, 4 dwg

Description

The invention relates to rocket technology.

A known thrust unit of a liquid propellant engine (LRE), including a power frame, a rotary combustion chamber with a nozzle, bottom protection with movable and fixed screens and a gap between them, is seen from the description of the invention to patent RU 2347725 C2, B64G 1/52, B64G 1 / 40 on the "Bottom protection of the tail unit of the launch vehicle", published on 02.27.2009

According to its characteristics and the achieved result, this thrust block of the rocket engine is closest to the claimed one and adopted as a prototype.

The known thrust unit is made with approximately equal thickness bottom protection screens installed in the area of the outer end of the nozzle.

The disadvantage of such a thrust rocket engine thrust block is its low reliability due to the high temperature in the cavity with the block mechanisms and the power frame.

The objective of the invention is to increase the reliability of the block.

This problem is solved by improving the thrust block of the rocket engine, including a power frame, a rotary combustion chamber with a nozzle, bottom protection with movable and fixed screens and a gap between them.

The improvement lies in the fact that the bottom protection is installed near the critical diameter of the nozzle and is made with a gap between the movable and fixed screens at a diameter smaller than the outer diameter of the nozzle exit;

the fixed screen is made with a convex outward surface;

the fixed screen is made with increasing wall thickness in the direction of the nozzle;

the bottom protection is made with the outer surface of high reflectivity to thermal radiation.

The installation of bottom protection near the critical diameter of the nozzle and its execution with a gap between the screens at a diameter smaller than the outer diameter of the nozzle exit section made it possible to reduce the temperature in the cavity of the liquid-propellant rocket engine during its operation due to the location of most of the nozzle outside the block and the exclusion of radiation from the outer surface of the nozzle on the bottom protection, and reducing the penetration of heat flow from the torch of the rocket engine into the block through the bottom protection and, thereby, increase the reliability of the thrust unit of the rocket engine.

The execution of a fixed screen with a convex outward surface allowed him to reflect a significant part of the heat flux emanating from the surface of the nozzle and torch of the rocket engine in the direction of the cavity of the block with mechanisms and the power frame, and thereby lower the temperature in the cavity of the block.

The implementation of a fixed screen with increasing wall thickness in the direction of the nozzle allowed to reduce the heat flux through the screen into the cavity of the block.

The implementation of bottom protection from the nozzle with a surface of high reflectivity to thermal radiation has reduced the penetration of the latter into the cavity of the block.

Below, with reference to the accompanying drawing, where shown in

Figure 1 - General view of the block;

Figure 2 - block with a convex outer surface of a fixed screen;

Figure 3 - block with increasing wall thickness of a fixed screen;

Figure 4 - block with bottom protection of high reflectivity.

The thrust block of the liquid propellant rocket engine contains a power frame 1, a rotary combustion chamber 2 with a nozzle 3, a bottom guard 4 with a movable 5 and a fixed 6 screens and a gap 7 between them. In this case, the movable screen 5 is fixed on the outer surface of the nozzle 3, and the stationary screen 6 is fixed on the frame 1 by means of rods 8, sealed at the junction with the casing 9 of the block (the seal is not shown in Fig.), While the screen 6 forms a cavity with the casing 9 BUT.

The block is characterized in that the bottom protection 4 is installed near the critical diameter Dcr. nozzle 3 and is made with a gap 7 between the screens 5, 6 at a diameter D less than the outer diameter of the cut Dns nozzle 3.

In block versions:

figure 2 - fixed screen 6 is made with a convex outward surface 10;

figure 3 - fixed screen 6 is made with increasing

wall thickness B in the direction of the nozzle 3;

figure 4 - bottom protection 4 is made from the side of the nozzle 3 with the surface In high reflectivity to thermal radiation.

In the process of operation of the LRE during the combustion of fuel in an oxidizing medium, the walls of the nozzle 3 are heated to approximately 1700 ° C.

The movable and fixed screens can be made, for example, of carbon-ceramic material to reduce heat transfer to cavity A.

Installation of bottom protection 4 near the critical diameter Dkr. nozzle 3 and its execution with a gap of 7 between the screens 5, 6 on a diameter D smaller than the cut diameter of the nozzle Dns of the nozzle 3, allowed to reduce the temperature in the cavity A of the block in comparison with the prototype by about 2 times (when testing prototypes of the product from 400 ° C to 200 ° C).

In the process of operation of the rocket engine in block versions:

- with a stationary screen 6 and its surface 10 convex outward, it allowed to reflect a significant part of the heat flux from penetration into cavity A;

- with a fixed screen 6 and an increasing thickness B of its wall in the direction of the nozzle 3, the heat flux penetrated into the cavity A through the wall of the screen 6;

- with bottom protection 4 from the side of nozzle 3 with surface B of increased reflectivity (for example, mirror), the penetration of heat flux into cavity A through surface B and wall B of bottom protection 4 is even more reduced.

The thrust block of the rocket engine in comparison with the prototype allows it to reduce the penetration of thermal rays into the cavity A both from the surface of the nozzle and from the torch of the rocket engine.

The implementation of the thrust unit of the rocket engine according to the invention provides an increase in its reliability compared to the prototype.

Claims (4)

1. The thrust unit of a liquid-propellant jet engine comprising a power frame, a rotary combustion chamber with a nozzle, bottom protection with a movable and fixed screens and a gap between them, characterized in that the bottom protection is installed near the critical diameter of the nozzle and is made with a gap between the screens on the diameter, smaller than the outer diameter of the nozzle exit. 2. The block according to claim 1, characterized in that the fixed screen is made with a convex outward surface. 3. The block according to claim 1, characterized in that the fixed screen is made with increasing wall thickness in the direction of the nozzle. 4. The block according to claim 1, characterized in that the bottom protection is made from the side of the nozzle with a surface of high reflectivity to thermal radiation.

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