JP2014037177A - Jet interaction actuator and atmospheric re-entry vehicle including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce dependency on jet air flow injection for attitude control of a vehicle body and reduce a loading amount of propellant by positively utilizing jet interaction effects to increase a vehicle body payload and downsize the vehicle body.SOLUTION: Jet interaction actuators 5A, 5B are designed to control an attitude of an atmospheric re-entry vehicle by utilizing jet interaction effects, and the actuator comprises: a wall body 6 that rises from a pressure-receiving surface 3, against which supersonic air current hits, of a vehicle body 2 of the atmospheric re-entry vehicle; and a jet injection nozzle 7 which is formed at a position at least on one side of the wall body 6 with a predetermined distance L from the top portion (bottom surface 6b) of the wall body 6, and injects jet air flow J in a direction orthogonal to a surface direction of a side surface 6a of the wall body 6.

Description

  The present invention relates to a jet interference actuator using the jet interference effect and an atmospheric re-entry machine using the same.

  There are two types of attitude control methods for spacecraft that re-enter the atmosphere (atmosphere re-entry aircraft): a method that uses aerodynamic torque by control surface steering and a method that uses thrust generated by jet stream thrust (thruster). The latter is common for capsule-type spacecraft returning from a circular orbit.

  However, the volume in the capsule is limited, and in order to fully load propellants (compressed gas, fuel, etc.) for jet air current injection, the payload (transportation capacity) of the fuselage is reduced, for example. It may be necessary to ensure. For this reason, efforts have been made to minimize propellant consumption.

  On the other hand, since the supersonic region of Mach 1 or higher is reached when the spacecraft enters the atmosphere, as shown in Non-Patent Documents 1 and 2, the aerodynamic force generated between the jet air jet and the external supersonic airflow is generated. Due to the interference, a complex flow field including a plurality of shock waves and separated vortices is formed around the jet hole of the jet stream. Due to this aerodynamic interference, the airframe surface pressure changes, and as a result, the airframe is affected by the force of aerodynamic interference in addition to the reaction force of the jet airflow. This phenomenon is generally called a jet interaction effect (Jet Interaction), and has a great influence especially in the hypersonic region of Mach 5 or higher.

  For this reason, as described in Patent Document 1, it is difficult to control the attitude of the airframe by jet airflow injection, and there is a problem that predetermined mobility cannot be obtained. In addition, when this happens, the degree of jetting the jet stream (injection time, number of injections, etc.) increases, and there is also a problem that more propellant than expected is consumed.

  Until now, the jet interference effect has only been recognized as a problem that makes it difficult to control the attitude of the aircraft as described above, and there has been no technology that actively uses the jet interference effect.

ADVISORY GROUP FOR AEROSPACE RESEARCH & DEVELOPMENT AGARD-AG-173, Page 4, 1973. Mitsuru Kurita, Takumi Okada, Yoshiro Nakamura, “Side Jet Aerodynamic Interference in Hypersonic Blunt Objects”, Japan Aerospace Society Proceedings, Vol.50, No.585, Page394, 2002.

JP-A-6-147799

  In a relatively small capsule-type spacecraft, the internal volume is limited as described above, so the amount of propellant for the jet stream is reduced as much as possible to ensure a large payload, or the aircraft is downsized. There is a demand to do.

  The present invention has been made in view of the above circumstances, and by actively utilizing the jet interference effect, the dependence of jet air current injection for controlling the attitude of the aircraft is reduced and the amount of propellant loaded is reduced. It is another object of the present invention to provide a jet interference actuator capable of increasing the payload of a fuselage or reducing the size of the fuselage and an atmospheric re-entry machine equipped with the jet interference actuator.

In order to solve the above problems, the present invention employs the following means.
That is, the jet interference actuator according to the present invention is a jet interference actuator that controls the attitude of the atmospheric re-entry machine using the jet interference effect, and the supersonic airflow of the airframe of the atmospheric re-entry machine is A wall standing up from a pressure-receiving surface that collides with, and at least one surface of the wall is formed at a predetermined distance from the top of the wall and jets a jet stream in a direction perpendicular to the surface direction of the wall A jet injection hole.

  According to the above configuration, when the atmospheric re-entry aircraft re-enters the atmosphere, that is, when a supersonic airflow collides with the pressure receiving surface of the atmospheric re-entering device, both sides of the wall standing up from the pressure receiving surface of the aircraft are supersonic. When a jet stream is jetted from a jet injection hole in this state, the wall pressure in the region between the top of the wall and the jet injection hole increases due to the jet interference effect, and this pressure causes the wall to Pressed.

  Therefore, in addition to the reaction force of jet airflow injection, the wall surface is also pressed by the jet interference effect, so that the wall surface can be pressed with a stronger force than the case of only the reaction force of jet airflow injection. The posture control becomes easy. For this reason, the dependency on jet stream injection can be reduced, and accordingly, the amount of propellant for jet stream injection can be reduced, and the payload of the atmospheric re-entry aircraft can be increased, or the size of the aircraft can be reduced. Can do.

  In addition, an atmosphere re-entry machine according to the present invention includes the jet interference actuator described above.

  According to this atmospheric re-entry machine, the wall surface is pressed by the reaction force of the jet stream injected from the jet injection hole provided in the wall of the supersonic jet interference actuator and the supersonic stream interferes with the jet stream. Since the wall surface is pressed by both of the jet interference effect, the wall surface can be pressed with a stronger force than the case of only the reaction force of jet air jet. For this reason, the dependence of jet airflow injection can be reduced, the amount of propellant loaded for jet airflow injection can be reduced, and the payload of an atmospheric re-entry machine can be increased or the size of the airframe can be reduced.

  In addition, the atmosphere re-entry aircraft according to the present invention has a symmetric shape formed by a curved line or a straight line in a plan view of the airframe in the above-described configuration, and passes through a substantially central portion and a center of gravity position of the airframe. The jet interference actuator is provided near one end or both ends of a reference line, respectively, and the surface direction of the wall body in each jet interference actuator is along the horizontal reference line.

  According to the above configuration, the jet airflow injected from the jet injection holes of the wall body in each jet interference actuator is from one end or both ends of the horizontal reference line passing through the substantially center portion and the center of gravity of the body in plan view. Injected at right angles. For this reason, the reaction force of jet air flow injection and the pressing force due to the supersonic jet interference effect are most efficiently converted into a force for rotating the aircraft around the center of gravity of the aircraft. Therefore, it is possible to efficiently control the attitude of the airframe by the jet interference actuator, reduce the consumption of the propellant for jet stream injection, and reduce the amount of propellant mounted.

  In addition, in the above configuration, the atmospheric re-entry aircraft according to the present invention is configured such that, in plan view, the center of gravity position is deviated from an intermediate point of the horizontal reference line toward one of the jet interference actuators. Features.

  According to the above configuration, when the atmospheric re-entry machine re-enters the atmosphere at an angle, if the wind pressure center point due to the air flow is shifted from the center of gravity of the aircraft in the supersonic air flow, the two appear to match. The aircraft will rotate to determine the longitudinal direction of the aircraft. The horizontal reference line of the aircraft is along this longitudinal direction, and jet interference actuators are provided at both ends of this horizontal reference line, so the jet interference actuators are always at the front end position and the rear end position of the aircraft. Attitude control becomes easy. Therefore, it is possible to efficiently control the attitude of the airframe by the jet interference actuator, reduce the consumption of the propellant for jet stream injection, and reduce the amount of propellant mounted.

  In addition, the atmospheric re-entry machine according to the present invention has a wind pressure center point due to the supersonic air flow and the center of gravity position of the airframe in a side view of the airframe when the air reentry aircraft is reentering the atmosphere and descending in the above configuration. And at least one of the jet interference actuators is installed at a position where a straight line connecting the position of the center of gravity and the installation position of the jet interference actuator is substantially perpendicular. .

  According to the above configuration, at the time of re-entry, when the aircraft is tilted so that the wind pressure center point coincides with the center of gravity position of the aircraft, as viewed from the center of gravity position, the straight axis passing through the wind pressure center point and the center of gravity position. By arranging the jet interference actuator on a vertical straight line, a force generated when jet air current is ejected from the jet interference actuator is used to rotate the airframe around an axis other than the straight axis passing through the wind pressure center point and the center of gravity G. For example, it is possible to eliminate the force of swinging the aircraft from side to side, which makes it easier to control the attitude of the aircraft. Therefore, it is possible to efficiently control the attitude of the airframe by the jet interference actuator, reduce the consumption of the propellant for jet stream injection, and reduce the amount of propellant mounted.

  As described above, according to the jet interference actuator according to the present invention and the atmospheric re-entry aircraft equipped with the same, the dependence of the jet air flow injection for controlling the attitude of the aircraft can be reduced by actively utilizing the jet interference effect. It is possible to reduce the amount of propellant loaded, increase the payload of the aircraft, or reduce the size of the aircraft.

It is a perspective view of the atmospheric re-entry machine concerning the embodiment of the present invention. It is a side view of the atmospheric reentry machine by the II arrow of FIG. It is a bottom view of the atmosphere reentry machine by the III arrow view of FIG. It is a side view of the jet interference actuator which shows embodiment of this invention by the IV arrow view of FIG. It is a side view which shows the attitude | position of the body at the time of atmospheric reentry.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an atmospheric reentry machine according to an embodiment of the present invention.
As shown in FIG. 1 to FIG. 3, the atmospheric reentry machine 1 has a substantially frustoconical airframe 2 that is circular in plan view (see FIG. 3), and the bottom surface of the air reentry machine is a supersonic airflow when reentering the atmosphere. It is the pressure receiving surface 3 where it hits. At the time of re-entry into the atmosphere, the attitude of the airframe 2 is controlled so that the pressure receiving surface 3 faces substantially in the traveling direction. The pressure receiving surface 3 gently rises from the outer peripheral contour line O of the body 2 into a convex lens shape.

  The atmosphere reentry machine 1 includes a pair of jet interference actuators 5A and 5B. The airframe 2 has a symmetrical shape with respect to a plane (S shown in FIG. 3) including the jet interference actuators 5A and 5B and the airframe center axis C. As will be described later, these jet interference actuators 5A and 5B rotate the airframe 2 around the central axis C of the airframe 2 and use the airflow 2 in flight while using both the jet airflow injection and the jet interference effect. The attitude of the airframe 2 is controlled by moving the robot horizontally. Only one of these two jet interference actuators 5A and 5B may be provided.

  The installation positions of the jet interference actuators 5A and 5B are in the vicinity of both ends of the horizontal reference line S passing through the substantially central portion of the airframe 2 and the gravity center position G in a plan view of the airframe 2 (see FIG. 3). In the present embodiment, the substantially central portion of the airframe 2 is the vicinity where the central axis C of the airframe 2 passes. Further, the horizontal reference line S is equal to the plane of symmetry of the airframe 2 projected in plan view.

  The center-of-gravity position G of the machine body 2 is deviated from an intermediate point of the horizontal reference line S (a point where the central axis C is orthogonal) to, for example, one jet interference actuator 5A side. For this reason, the other jet interference actuator 5 </ b> B is provided at a position farthest from the gravity center position G in plan view of the airframe 2.

  The jet interference actuators 5 </ b> A and 5 </ b> B include a wall body 6 that rises from the pressure receiving surface 3 of the airframe 2. The wall body 6 has sufficient strength against a supersonic airflow, and has a minimum thickness capable of incorporating a thruster (jet injection device) to be described later. In a plan view (see FIG. 3), it is along a horizontal reference line S that passes through a substantially central portion of the body 2 and the center of gravity G. Further, the wall body 6 is substantially perpendicular to the outer peripheral contour line O of the body 2 in a side view of the body 2 (see FIG. 4).

  This is because the fuselage is axisymmetric with respect to the symmetry plane including the horizontal reference line S shown in FIG. 3, and thrust is generated symmetrically from both sides of the wall 6 with respect to any rotation axis contained in this symmetry plane. However, the surface direction may be set so as to be perpendicular to a desired thrust direction and does not necessarily have to be a right angle. Furthermore, although the lower surface 6b of the wall body 6 is substantially planar, it may not be a plane. In addition, as shown in FIG. 4, the corner | angular part which the side surface 6a and the lower surface 6b contact is rounded in consideration of aerodynamic heating.

  A total of four jet injection holes 7 (thrusters) are provided on both surfaces of the pair of wall bodies 6. As shown in FIG. 4, these jet injection holes 7 inject a jet air flow J in a direction orthogonal to the surface direction of the side surface 6 a of the wall body 6. This jet airflow J is generated by injecting a compressed gas such as nitrogen or a gas obtained by burning fuel.

  As shown in FIG. 2, each jet injection hole 7 is provided in a region on the outer peripheral side in the diameter direction of the airframe 2 in each wall body 6, and as shown in FIG. 4, the top portion (lower surface 6 b) of each wall body 6. ) Is preferably provided at a position at a predetermined distance L. Furthermore, it is preferable to open the jet injection holes 7 at a certain distance from the pressure receiving surface 3 so that the plume (jet air flow) of the jet air current J does not interfere with the pressure receiving surface 3 of the body 2. In the present embodiment, each jet injection hole 7 is formed in a single small hole shape, but for example, a plurality of small holes arranged in the horizontal direction, or a slit shape extending in the horizontal direction, It is possible to make it into a shape.

  The atmosphere reentry machine 1 configured as described above descends while receiving a supersonic airflow of Mach 1 or higher on the pressure receiving surface 3 of the airframe 2 when reentering the atmosphere. In order to control the attitude of the airframe 2 under this situation, the jet airflow J is ejected from the jet ejection holes 7 of the jet interference actuators 5A and 5B. For example, when jet air current J is ejected from the jet injection holes 7 on the same side of the pair of wall bodies 6, the body 2 can be translated in the horizontal direction. Further, when the jet airflow J is ejected from the jet ejection holes 7 on different sides of the pair of wall bodies 6, the body 2 can be rotated about the central axis C. By combining these movements, it is possible to guide the atmospheric re-entry machine 1 to a predetermined landing point.

  When the jet stream J is ejected from the jet spray hole 7, the wall body 6 is pressed by the jet interference effect in addition to the reaction force F1 (see FIG. 4) of the jet stream J. That is, when re-entering the atmosphere, that is, when a supersonic airflow is colliding with the pressure receiving surface 3 of the airframe 2, the both sides 6 a of the wall body 6 standing up from the pressure receiving surface 3 are superposed as shown in FIG. 4. When a sonic airflow flows and jet airflow J is ejected from one jet injection hole 7 in this state, an area between the top (lower surface 6b) of the wall body 6 and the jet injection hole 7 (FIG. 4) due to the jet interference effect. The wall pressure in the hatched portion) rises, and the side surface 6a of the wall body 6 is pressed by the pressing force F2 due to this pressure.

  As described above, the side surface 6a of the wall body 6 is also pressed by the pressing force F2 due to the jet interference effect in addition to the reaction force F1 caused by the jet airflow injection J. Therefore, by using these forces F1 and F2 in combination, The side surface 6a can be pressed with a stronger force than in the case of only the reaction force F1 of the airflow jet J, and the attitude control of the atmospheric re-entry machine 1 is facilitated. For this reason, the dependence rate to jet air current injection can be reduced.

  For example, it is possible to reduce the injection amount of jet air current injection or shorten the injection time, and accordingly, to reduce the loading amount of propellant for jet air current injection, increase the payload of the atmospheric re-entry machine 1, Alternatively, the size of the body 2 can be reduced. According to the estimation by the inventors, the amount of the propellant for jet stream injection can be reduced by about 20% compared to the conventional configuration by adopting the above configuration.

  Moreover, since at least one of the jet interference actuators 5A is provided at the farthest position from the center of gravity G of the airframe 2 in plan view of the airframe, the reaction force F1 of the jet air jet J and the jet interference effect in the jet interference actuator 5A Can be most effectively converted into a moment of force that changes the attitude of the body 2. For this reason, the mounting amount of the propellant for jet air current injection can be reduced, which can contribute by increasing the payload or reducing the size of the airframe 2.

  Furthermore, jet interference actuators 5A and 5B are provided in the vicinity of both ends of the horizontal reference line S passing through the substantially central portion of the circular airframe 2 and the gravity center position G in plan view of the airframe 2, and the walls of these jet interference actuators 5A and 5B are respectively provided. Since the surface direction of the body 6 is along the horizontal reference line S, the jet air flow J injected from the jet injection holes 7 of the wall body 6 in each jet interference actuator 5A, 5B is the center of gravity of the body 2 in plan view of the body. Jetted in the direction perpendicular to both ends of the horizontal reference line S passing through the position G.

  For this reason, the reaction force F1 of the jet airflow injection J and the pressing force F2 due to the supersonic jet interference effect are most efficiently converted into a force for rotating the airframe 2 around the center of gravity G of the airframe 2. Therefore, the attitude control of the airframe 2 by the jet interference actuators 5A and 5B can be efficiently performed, the consumption amount of the propellant for jet stream injection can be reduced, and the propellant loading amount can be reduced.

  Moreover, since the gravity center position G of the airframe 2 is biased from the intermediate point of the horizontal reference line S (point C in FIG. 3) to, for example, one jet interference actuator 5A side in the airframe plan view, the following Action and effect are obtained.

  That is, as shown in FIG. 5, when the atmospheric re-entry machine 1 re-enters the atmosphere obliquely, the center-of-gravity position G of the airframe 2 and the wind pressure center point WP due to the supersonic airflow are in the descending direction in a side view. The body 2 rotates around a straight line PL that is perpendicular or substantially perpendicular to a plane passing through the center of gravity G and the wind pressure center point WP so as to coincide with the straight line DL along the line DL, and is stabilized in this posture. Thereby, the front-back direction of the body 2 is determined.

The horizontal reference line S of the airframe 2 is along the front-rear direction, and the jet interference actuators 5A and 5B are provided at both ends of the horizontal reference line S. Therefore, the jet interference actuators 5A and 5B are always at the front end position of the airframe 2. Positioned at the rear end position, this facilitates the attitude control of the airframe 2.
Therefore, the attitude control of the airframe 2 by the jet interference actuators 5A and 5B can be efficiently performed, the consumption amount of the propellant for jet stream injection can be reduced, and the propellant loading amount can be reduced.

  The center of gravity position G of the fuselage 2 and the wind pressure center point WP due to the supersonic airflow are tilted so as to coincide with a straight line (DL) along the descending direction, and the center of gravity position is viewed from the center of gravity position G. By arranging the jet interference actuator 5B on a straight line PL substantially perpendicular to the straight line DL passing through G and the wind pressure center point WP, the airframe 2 generated when the jet air flow J is injected from the jet injection hole 7 other than the straight line DL For example, a force for rotating the body 2 to the left or right can be eliminated, and this makes it easier to control the attitude of the body 2. Therefore, the attitude control of the airframe 2 by the jet interference actuators 5A and 5B can be efficiently performed, the consumption amount of the propellant for jet stream injection can be reduced, and the propellant loading amount can be reduced.

  As described above, according to the jet interference actuators 5A and 5B and the atmospheric reentry machine 1 including the jet interference actuators 5A and 5B according to the present invention, the jet that controls the attitude of the airframe 2 by actively utilizing the jet interference effect. It is possible to reduce the dependency of the airflow injection and reduce the amount of propellant mounted, thereby increasing the payload of the airframe 2 or reducing the size of the airframe 2.

It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and can be appropriately modified or improved within a scope not departing from the gist of the present invention. Are also included in the scope of rights of the present invention.
For example, the shape of the airframe 2 is not necessarily a truncated cone shape. The plane view shape of the airframe 2 is not limited to the circular shape shown in FIG. Further, the shape of the pressure receiving surface 3 of the airframe 2 and the installation structure of the jet interference actuators 5A and 5B with respect to the pressure receiving surface 3 may be other structures.
Further, the number of installed jet interference actuators 5A and 5B is not limited to two at the front and rear, but only at the front and only at the rear, and may be applied in combination with a normal thruster as appropriate.

DESCRIPTION OF SYMBOLS 1 Atmospheric re-entry machine 2 Airframe 3 Pressure receiving surface 5A, 5B Jet interference actuator 6 Wall body 6a Side surface 6b of wall body Bottom surface of wall (top of wall)
7 Jet injection hole C Center axis DL Straight line passing the wind pressure center point and the center of gravity of the aircraft F1 Reaction force F2 of the jet stream injection J Pressing force G due to the jet interference effect J Center of gravity J Jet stream L Jet jet hole from the top of the wall Distance PL Distance between the center of gravity of the aircraft and the installation position of the jet interference actuator S Horizontal reference line WP Wind pressure center point

Claims (5)

A jet interference actuator that uses the jet interference effect to control the attitude of the atmospheric re-entry machine,
A wall body standing up from a pressure-receiving surface where the supersonic airflow of the airframe re-entry machine hits,
A jet injection hole which is formed at a predetermined distance from the top of the wall body on at least one side of the wall body and jets a jet stream in a direction perpendicular to the surface direction of the wall body;
A jet interference actuator comprising:   An atmosphere re-entry machine comprising the jet interference actuator according to claim 1.   In the plan view of the airframe, the airframe has a symmetrical shape formed by a curved line or a straight line, and the jet interference actuator is provided near one end or both ends of a horizontal reference line passing through the substantially center portion and the center of gravity of the airframe. The atmosphere re-entry machine according to claim 1, wherein a surface direction of the wall body in each of the jet interference actuators is along the horizontal reference line.   The atmospheric re-entry machine according to claim 3, wherein the center of gravity position is biased toward one of the jet interference actuators from an intermediate point of the horizontal reference line in a plan view of the airframe.   When the aircraft re-enters the atmosphere and descends, in a side view of the aircraft, a straight line passing through the wind pressure center point due to the supersonic air flow and the gravity center position of the aircraft, and the gravity center position and installation of the jet interference actuator The atmosphere re-entry machine according to any one of claims 2 to 4, wherein at least one of the jet interference actuators is installed at a position where a straight line connecting the positions is substantially perpendicular.

Images