RU2643073C1 - Method of descent of separating part of launch vehicle - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention concerns separating parts (SP) of the launch vehicles (LV) as they move along the trajectory of descent. Descent of LV SP on liquid fuel components to the specified impact area is based on the stabilization of SP, orientation and controlled movement of the SP due to energy in residual liquid fuel components on the basis of their gasification and feeding to engine unit. At that, after entering the atmosphere, the value of the balancing angle of attack, its orientation providing a transition to the falling trajectory of descent to the set aiming point, is calculated. Parameters of the spiral trajectory ("Spiral") along which the flight is carried out with the balancing angles of attack relative to the falling trajectory of descent, is calculated. At that, the transition of the SP to the "Spiral" is carried out with the achievement of values aerodynamic moment which provides possibility to manoeuvre of SP to the "Spiral" from the trajectory of the uncontrolled descent of the SP, and the lower end of the "Spiral" contacts the beginning of the retrograde portion trajectory on which a retrograde burn is completed. The movement of SP along the "Spiral" is executed by turning SP at an angular speed determined based on the condition of SP enters the beginning of retrograde portion with a minimum speed of movement of the SP masses center.

EFFECT: reduced weight of the structure, increased accuracy of landing the separating parts, reduced load on the separating parts body.

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Description

The invention relates to rocket and space technology, in particular to launch vehicles (LV) on the liquid components of rocket fuel (KPT), and in particular to the separating parts (OH) of the stages of the launch vehicle during their movement along the descent paths.

A technical solution is known for the method of controlling flight of an aircraft in the atmospheric section of the descent trajectory according to patent RU No. 2495802 dated 10.20.2013, where an aerospace parachute system made of heat-resistant materials and means of passive orientation, stabilization is used when separating the VHF at an altitude of more than 70 km, braking and thermal protection, at an altitude below 10 km a parachute system is used and at an altitude below 3 km a helicopter interceptor is used.

However, the use of this technical solution is associated with the attraction of significant funds, including parachute systems, helicopter pickup.

The closest in technical essence to the proposed solution is patent RU No. 2414391 dated 03/20/2011, “Method for lowering the separating part of the PH stage and a device for its implementation”, in which the lowering of the PH stage of the PH on liquid SRT to a predetermined area of incidence is based on stabilization of the PH the position of the propulsion system forward, the orientation and controlled movement of the PF, after separating the PF, the descent maneuver to the specified drop area is carried out due to the energy contained in the undeveloped SRT residues based on their gasification and supply to the gas crab hydrochloric propulsion system (GzRDU) and traffic control center of mass and center of mass around OCH carried deviations GzRDU cameras installed in single-stage actuators.

The disadvantages of this technical solution include the high speed of the landing gear at the landing point, which when solving issues on the development of soft landing systems leads to the need for significant energy costs for braking the landing gear and, consequently, the weighting of the design of the soft landing system of the ocher (see, for example, soft landing the first stage of the Falcon-9 launch vehicle http://www.spacex.com. Patent RU No. 2309089 of 10.27.2007 "The method of returning the reusable first stage to the spaceport").

The objective of the proposed technical solution is to increase the efficiency of the method of launching the VF by reducing the speed of the VF when touching the surface of the area of incidence based on the introduction of the flight mode of the VF with balancing angles of attack along a spiral descent path.

This technical result is achieved by the fact that in the method of lowering the RL stage of LV on liquid SRT to a predetermined area of incidence, based on stabilization and orientation of the RL due to the energy contained in the undeveloped residues of liquid SRT based on their gasification, the following actions are introduced:

a) after entering the atmosphere, calculate the value of the balancing angle of attack (α _b ), its orientation, providing a transition to the falling trajectory of descent to a given aiming point;

b) calculate the parameters of the spiral trajectory (hereinafter referred to as the “Spiral”), along which flight with balancing angles of attack α _b relative to the falling descent trajectory is carried out, while the transition of the IF to the “Spiral” is carried out with the achievement of the values of the aerodynamic moment, which provides the possibility of maneuvering the transition of the AF to “Spiral” from the path of uncontrolled lowering of the OCh, and the lower end of the “Spiral” refers to the beginning of the trajectory of the brake section, where the brake pulse is worked out;

c) the movement of the ocher along the spiral is carried out by turning the ocher with an angular velocity determined from the condition that the ocher hits the beginning of the brake section with the minimum velocity of the center of mass of the ocher.

The implementation of the proposed technical solution is illustrated in Fig., Where:

1 - OCh in the descending part of the extra-atmospheric section of the descent trajectory 1-3-8-9 without the implementation of the proposed aerodynamic descent maneuver;

2 - entrance to the atmosphere (h ~ 100 km);

3 - section transition OCh on the falling trajectory of descent 4 and "Spiral" 5;

5 - "Spiral", starting from the end of section 3 and ending at point 6 - the beginning of the trajectory of the braking section of the VL and lying on the falling trajectory 4;

7 - the displaced point of incidence of OCh;

8 - the path of descent of the PF without aerodynamic maneuver by changing the point of incidence of the PF;

9 - point of fall of the OCh without aerodynamic maneuver;

10 - OCh on the "Spiral" with balancing angles of attack.

1. The balancing angle of attack α _{b is} calculated from the condition that the aerodynamic moment is equal to zero (see book 1, Appazov RF, Sytin OG Methods of designing the trajectories of launch vehicles and Earth satellites. Nauka Publishing House, 1987. S. 427-428). For example, for the planar case necessary to select a value of the spatial angle of attack α _b / (α _z), which is a function only of the angle of attack to the corresponding point in the aerodynamic pitch channel is zero:

This is achieved by ensuring the coincidence of the center of mass and the center of pressure. Using the ANSYS FLUENT software product, M _Z is calculated at various angles of attack based on the numerical solution of the Navier-Stokes equations (see book 2, Krasnov AF Aerodynamics. 1980, part 1, 2 p. 105). At different angles of attack, the picture of the flow around the OC changes, as a result of which the coordinate of the pressure center changes, and when the condition of coincidence of the coordinates of the center of pressure and the center of mass is reached, condition (1) is realized.

For the three-dimensional case, which is the case for the proposed descent scheme, it is necessary to ensure that the aerodynamic moment is zero in the pitch and yaw channels:

which is provided for this spatial balancing angle of attack α _b (α _z, α _y), which is already as a function of the angle of attack α _z and sliding α _y. The determination of the balancing angle of sliding α _{y is} carried out similarly to the determination of the balancing angle of attack α _z .

2. Calculation of the "Spiral" parameter, which is carried on with balancing flight angles of attack α _b:

- “Spiral” represents a trajectory similar in meaning to the phasing orbit when the spacecraft approaches in orbits (see book 4, The Engineering Guide for Space Technology / edited by A.V. Solodov, Moscow: published by the Ministry of Defense USSR, 1977. S. 106-108), i.e. the transition to the orbit (trajectory), the movement along which, in addition to solving the transport problem, also provides for the satisfaction of an additional condition, for example, the approach to the end point at a given point in time. In this case, the “Spiral” provides braking of the ocher, rotating and decreasing near the falling path 4, providing a planning descent of the ocher with the given balancing angles of attack (poses 3-5-6 of Fig. 1) with pos. 3 in pos. 6;

- the upper end of the “Spiral” (end of section 3) begins with the achievement of the values of the aerodynamic moment, which provides the possibility of maneuvering the transition to the “Spiral” from the path of uncontrolled descent of the PF (the beginning of section 3,8,9);

- the lower end of the “Spiral” refers to the beginning of the brake section (pos. 5), the brake section - the vertical section of the descent trajectory where the brake pulse is worked out using a special brake rocket propulsion system (see, for example, the descent of the spent Falcon-9 stage) www.spacex.com, and also according to the patent of the Russian Federation No. 2414391 dated 03/20/2011, “Method for lowering the separating part of the PH stage and device for its implementation”).

3. The movement of the ocher along the "Spiral" is carried out by turning the ocher with an angular velocity determined from the condition that the ocher hits the beginning of the brake section with the minimum velocity of the center of mass of the ocher, with:

в плоскости угла скольжения, которое формируется за счет сопел газореактивной системы ОЧ;- the angular velocity of the reversal of the OHP ω _xc is realized by the formation of the control moment

in the plane of the slip angle, which is formed by the nozzles of the gas reactive system of the OF;

- the value of ω _xc and the time of movement along the “Spiral” are made using the optimization method (see, for example, book 3 Lesin V.V. Fundamentals of optimization methods: a training manual / Lesin V.V., Lisovets Yu.P. - St. Petersburg: Doe, 2011 .-- 342 p.). The optimization criterion (in this case, minimization) is the value of the velocity of the center of mass of the optical element at the beginning of the braking section (pos. 6) or the value of the braking impulse.

Using the proposed method of descent allows you to significantly reduce the cost of braking the stage if the implementation of soft landing. For example, the assessments made during the traditional descent of the first-stage OC of the Soyuz-2.1.v LV show that at zero angle of attack the passive flight time is 353 s, and the speed of the center of mass of the OC when it touches the surface of the incidence region is ~ 169 m / s.

When using the proposed method of launching the VL with balancing angles of attack (in the range of 30 ° -60 °), the passive flight time is ~ 500 s, and the VL velocity at the point of contact of the surface of the incidence region is ~ 75 m / s, therefore, as can be seen from the above example for the first-stage pilot launch vehicle Soyuz-2.1.v, the application of the proposed descent method allows:

- significantly (about 2 times) to reduce fuel reserves to damp the speed of the center of mass of the HF during soft landing, respectively, to reduce the mass of the structure of fuel tanks;

- an increase in the time of descent of the ocher, respectively, will increase the magnitude of the displacement of the aiming point relative to the original, as well as increase the accuracy of landing of the ocher;

- OCh movement along the “Spiral” trajectory unloads the OCh body from bending moments, respectively, reduces the load on the OCh body;

- an increase in the descent time leads to an increase in fuel consumption for stabilization and orientation of the PF, however, given the small amount of disturbing moments due to the movement of PF at the balancing angles, this increase is insignificant compared to the saving of fuel reserves for the implementation of the braking impulse.

Claims (1)

The method of launching the separating part (OCh) of the carrier rocket on liquid fuel components to a predetermined area of incidence, based on the stabilization of the OCh, orientation and controlled movement of the OCh due to the energy contained in the undeveloped residues of the liquid fuel components based on their gasification and supply to the propulsion system, characterized in that after entering the atmosphere, the value of the balancing angle of attack is calculated, its orientation, which provides a transition to the falling descent trajectory at a given aiming point, steam is calculated meters of a spiral trajectory (“Spiral”), along which flight with balancing angles of attack relative to the falling descent trajectory is carried out, while the transition of the IF to the “Spiral” is carried out with the achievement of the values of the aerodynamic moment, which makes it possible to maneuver the transition of the IF to the “Spiral” from the uncontrolled trajectory the descent of the ocher, and the lower end of the “Spiral” concerns the beginning of the trajectory of the brake section, where the brake pulse is worked out, the movement of the ocher along the “Spiral” is carried out by turning the ocher with the angular velocity determined from the condition that the HF gets into the beginning of the brake section with the minimum speed of the center of mass of the HF.

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