JPH0939899A - Atmosphere reentry capsule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decease aerodynamic heat and acceleration of decelerating, to be received by an atmosphere reentry capsule in reentering the atmosphere, by developing a plurality of decelerating plates housed in machine side surfaces on the circumearth orbit from the machine body surfaces according to the specified sequence after reentering the atmosphere. SOLUTION: In a capsule 1, a plurality of decelerating plates 5 are housed on machine body side surfaces, and the decelerating plates 5 are developed from the machine body by an actuator 6 according to the specified sequence after reentering the atmosphere. In this case, preferably, the developing amounts of the decelerating plates 5 are controlled by a controller 8 so that the acceleration of decelerating detected by an acceleration sensor 7 may be held to the approximately constant value after reentering the atmosphere. The decrease of the machine body is increased by the development of the decelerating plates 5, the deceleration of the machine body is speeded up, and the maximum aerodynamic heating amount to be applied to the capsule 1 is decreased. A peak value of the acceleration of decelerating to be applied to the machine body is decreased, and the conditions of environment of a capsule main body and the pay load are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reduction of aerodynamic heating and deceleration that an atmosphere re-entry capsule undergoes during re-entry.

[0002]

2. Description of the Related Art FIG. 10 is a schematic view of a conventional atmosphere reentry capsule, FIG. 10 (a) is a side view, and FIG. 10 (b).
FIG. 6 is a diagram showing a state at the time of reentry. The atmosphere re-entry capsule often has a shape as shown in FIG. 10 in order to increase the front projection area in consideration of the aerodynamic characteristics during re-entry. In the figure, 1 is a capsule body, and 2 is a hypersonic airflow. When such a re-entry capsule flies at a supersonic speed exceeding the speed of sound during re-entry into the atmosphere, a strong shock wave 3 is generated in front of the airframe, and air is rapidly compressed and converted into kinetic energy and heat energy. The front air is heated. This phenomenon is called aerodynamic heating.
In addition, the pressure of the compressed air produces a deceleration force on the capsule, which produces deceleration acceleration.

Aerodynamic heating is an important issue in airframe design, especially at the time of reentry into the atmosphere flying at supersonic speed. The kinetic energy of the air is converted into heat energy and the temperature of the airflow becomes high, and the heat flows into the thin layer of the air around the airframe, that is, the boundary layer, and the temperature of the air in the boundary layer changes. To rise. The temperature rise of the ideal aircraft due to aerodynamic heating is proportional to the square of the flight Mach number at the time of reentry into the atmosphere, and is given by the following equation.

[0004]

[Equation 1]

Here, γ is the specific heat ratio of the airframe and is usually 1.
A value of about 4 is used. M∞ is the flight Mach number at the time of reentry into the atmosphere, and T∞ is the absolute temperature of the airframe. For example, the temperature is 0 ℃
When the atmosphere re-entry capsule flies in the air at 10 times the speed of sound, that is, Mach number M∞ = 10, the temperature of the air at the stagnation point of the atmosphere re-entry capsule becomes 5000 ° C. or higher.
In this way, from the air heated to a very high temperature, heat penetrates into the body surface through the boundary layer formed around the capsule, and the body temperature rises.

Further, in such an atmosphere re-entry capsule, a large deceleration acceleration occurs in the airframe when the atmosphere re-entry. FIG. 11 shows an example of the generated acceleration pattern.
The amount of aerodynamic heating shows almost the same pattern. In a ballistic capsule that does not have any trajectory changing mechanism, the magnitude of the deceleration acceleration that occurs changes with time, and is about 10 times the gravitational acceleration at the peak. The capsule body must have a structure that can withstand this maximum acceleration, and also has a significant impact on the environmental conditions of the internal payload that is the payload.

Aerodynamic heating and aerodynamic acceleration change depending on reentry parameters into the atmosphere, that is, plunge angle, capsule shape and mass. If the plunge angle is shallow, the frontal area is large, and the mass is light, both are reduced. To be done. However, in reality, there is a limit due to the conditions for mounting the launch vehicle and the constraints such as the dispersion of landing points after the entry. In particular, when the basic shape of the capsule is fixed, as described above, the deceleration acceleration is known to be about 10 times the gravitational acceleration.

[0008]

As described above, the atmosphere re-entry capsule undergoes severe aerodynamic heating and deceleration upon re-entry. Therefore, it is necessary to take a heat protection measure and an acceleration resistant structure capable of withstanding these conditions, and there is a problem that the payload mass cannot be sufficiently taken due to the increase in weight for that purpose.

Further, there is a problem that the payload is seriously damaged depending on the magnitude of the peak acceleration which is temporarily generated. Further, due to the constraints of the launch vehicle, there was also a problem that aerodynamic load and aerodynamic heating would be more severe if a sufficient capsule frontal area could not be taken for the mass.

The present invention has been made in order to solve such a problem, and is achieved by decelerating the flight speed of a capsule in a higher region of the atmosphere, which is higher than the altitude assumed to be subjected to maximum heating and maximum acceleration. The purpose is to suppress the maximum amount of aerodynamic heating applied to the capsule and further suppress the peak acceleration applied to the airframe.

[0011]

The atmosphere re-entry capsule according to the first embodiment of the present invention, according to a predetermined sequence,
An actuator is used to deploy a plurality of reduction plates from the machine body.

The atmosphere reentry capsule according to the second embodiment of the present invention detects deceleration acceleration applied to the airframe and controls the amount of expansion of the deceleration plate from the airframe by the detected value.

Further, the atmosphere reentry capsule according to the third embodiment of the present invention detects deceleration acceleration applied to the airframe, airframe angular velocity and attitude angle of the airframe, and based on these values, the expansion amount of the deceleration plate from the airframe is individually detected. To control.

Further, the atmosphere reentry capsule according to the fourth embodiment of the present invention has a braking film provided between adjacent speed reducers,
These are deployed from the machine body by an actuator according to a predetermined sequence.

Further, the atmospheric re-entry capsule according to the fifth embodiment of the present invention is one in which a circumferential slit is provided in the braking film between the adjacent reduction plates.

Further, the atmosphere reentry capsule according to the sixth embodiment of the present invention detects the deceleration acceleration applied to the airframe, and controls the expansion amount of the reduction plate and the braking film according to the value.

Further, the atmosphere reentry capsule according to the seventh embodiment of the present invention detects deceleration acceleration applied to the airframe, airframe angular velocity and attitude angle of the airframe, and based on these values, the expansion amounts of the speed reducer and the braking film are individually detected. To control.

[0018]

According to the first embodiment of the present invention, the capsule that has re-entered the atmosphere has a plurality of reduction plates deployed from the machine body by using actuators according to a predetermined sequence. The developed deceleration plate acts as a resistance and the deceleration of the capsule is accelerated, so that the maximum aerodynamic heating amount to the capsule is reduced and the maximum deceleration acceleration is reduced.

Further, according to the second embodiment of the present invention, the deceleration applied to the airframe after reentry into the atmosphere is detected, and the expansion amount of the deceleration plate from the airframe is controlled so as to maintain a substantially constant acceleration. The maximum acceleration is smaller than that in the first embodiment.

According to the third embodiment of the present invention, after the reentry into the atmosphere, the deceleration acceleration applied to the airframe is kept substantially constant, the generation of the angular velocity is suppressed, and the change of the attitude angle is reduced, so that the deceleration plate is reduced. Individually control the amount of deployment from the aircraft. Due to the stable attitude of flight, the environmental conditions to the capsule are further improved over those of Example 2.

Further, according to the fourth embodiment of the present invention, the braking force is further increased as compared with the first embodiment by providing the braking film between the adjacent speed reducing plates. By reducing the flight speed more efficiently, the maximum aerodynamic heating amount to the capsule is further reduced, and the maximum deceleration acceleration is also reduced.

Further, according to the fifth embodiment of the present invention, since the braking film has the slits in the circumferential direction, the air flow around the capsule is easily rectified, and the airframe flies more stably.

Further, according to the sixth embodiment of the present invention, the expansion amount of the reduction plate and the braking film from the airframe is controlled so as to maintain a substantially constant acceleration after reentry into the atmosphere. The maximum acceleration is smaller than that in the fourth embodiment.

Further, according to the seventh embodiment of the present invention, after the reentry into the atmosphere, the deceleration acceleration applied to the airframe is kept substantially constant, the generation of the angular velocity is suppressed, and the change of the attitude angle is reduced, so that the deceleration plate is reduced. And the amount of deployment of the braking film from the airframe is controlled individually. From flying in a stable attitude, the environmental conditions to the capsule are further improved.

[0025]

【Example】

Embodiment 1 FIG. 1 is an explanatory view showing a first embodiment of the present invention, and FIG. 1 (a) is a side view in an orbit around the earth, FIG.
(B) is a figure which shows the flight state of the capsule after re-entry. In FIG. 1, 5 is a reduction plate and 6 is an actuator. FIG. 2 is an explanatory diagram showing a pattern of acceleration and aerodynamic heating amount applied to the capsule according to the first embodiment of the present invention. In FIG. 2, the solid line a is the acceleration and aerodynamic heating amount of the first embodiment, and the broken line b is the acceleration and aerodynamic heating amount of the conventional capsule.

As shown in FIG. 1, the capsule 1 according to the present invention has a reduction plate 5 accommodated on the side surface of the machine body.
After re-entry into the atmosphere, a plurality of reduction plates 5 are deployed from the machine body by the actuator 6 according to a predetermined sequence.
The expansion of the speed reducer plate 5 increases the resistance of the airframe and accelerates the deceleration of the airframe as shown in FIG. 2. Therefore, the maximum aerodynamic heating amount applied to the capsule is reduced, and the peak value of the deceleration acceleration applied to the airframe is low. And the environmental conditions of the capsule body and payload are improved.

Embodiment 2 FIG. 3A and 3B are explanatory views showing a second embodiment of the present invention, FIG. 3A is a side view in an orbit around the earth, and FIG. 3B is a view showing a flight state of the capsule after reentry. is there. In FIG. 3, 7 is an acceleration sensor, 8 is a control device, and 9 is a control line. FIG. 4 is an explanatory diagram showing a pattern of acceleration and aerodynamic heating amount applied to the capsule according to the second embodiment of the present invention. In FIG. 4, the solid line C represents the acceleration and aerodynamic heating amount of the second embodiment.

As shown in FIG. 3, the second embodiment has an acceleration sensor 7 and a control device 8 inside the body of the first embodiment. In the second embodiment, after re-entry into the atmosphere, the control device 8 controls the expansion amount of the reduction plate 5 so that the deceleration acceleration detected by the acceleration sensor 7 maintains a substantially constant value. By controlling the expansion amount, the time change of the acceleration generated in the airframe is smoothed as shown in FIG. 4, and the maximum acceleration is further reduced.

Example 3. 5A and 5B are explanatory views showing a third embodiment of the present invention, FIG. 5A is a side view in an orbit around the earth, and FIG. 5B is a view showing a flight state of the capsule after reentry. is there. In FIG. 5, 10 is an angular velocity sensor. As shown in FIG. 5, the third embodiment has an angular velocity sensor 10 inside the airframe of the second embodiment. This Example 3
Then, after re-entry into the atmosphere, the deceleration acceleration detected by the acceleration sensor 7 maintains a substantially constant value, and the angular velocity of the airframe detected by the angular velocity sensor 10 and the attitude angle integrated and calculated in the control device 8 are stabilized. , The expansion amount of the reduction plate 5 is a control device 8
Controlled individually. Since the expansion amount can be controlled individually, the capsule can fly stably and the acceleration can be controlled easily.

Example 4. 6A and 6B are explanatory views showing a fourth embodiment of the present invention, FIG. 6A is a side view in an orbit around the earth, and FIG. 6B is a view showing a flight state of the capsule after reentry. is there. In FIG. 6, 11 is a damping film. Figure 6
As shown in FIG. 4, the fourth embodiment has the braking film 11 between the adjacent speed reducing plates 5 of the first embodiment, and after re-entry into the atmosphere, according to a predetermined sequence, the speed reducing plate 5 and the braking film 11 are arranged.
Is deployed from the machine body by the actuator 6. Due to the braking film 11, the aerodynamic frontal area of the capsule is larger, the braking force is higher than that of the first embodiment, and the deceleration efficiency is higher. Therefore, the aerodynamic heating and the deceleration are further reduced.

Example 5. FIG. 7 is an explanatory view showing Embodiment 5 of the present invention, FIG. 7 (a) is a side view in an orbit around the earth, and FIG. 7 (b) is a view showing a flight state of the capsule after reentry. is there. In FIG. 7, reference numeral 12 is a slitted braking film. As shown in FIG. 7, this fifth embodiment is similar to the fourth embodiment.
The braking film 12 with a slit is used for the braking film of
After re-entry into the atmosphere, the reduction plate 5
Using the actuator 6, the slitted braking film 12 is unfolded from the machine body. By providing the slit in the braking film, the air flow around the capsule is easily rectified, and the flight posture of the capsule is more stable.

Example 6. 8A and 8B are explanatory views showing a sixth embodiment of the present invention, FIG. 8A is a side view in an orbit around the earth, and FIG. 8B is a view showing a flight state of the capsule after reentry. is there. As shown in FIG. 8, the sixth embodiment has an acceleration sensor 7 and a control device 8 inside the airframe of the fourth embodiment. In the sixth embodiment, after re-entry into the atmosphere, the control device 8 controls the expansion amount of the reduction plate 5 and the braking film 11 so that the deceleration acceleration detected by the acceleration sensor 7 maintains a substantially constant value. By controlling the amount of expansion, the time change of the acceleration applied to the airframe is smoothed, and the maximum acceleration is further reduced.

Example 7. 9A and 9B are explanatory views showing a seventh embodiment of the present invention, FIG. 9A is a side view in an orbit around the earth, and FIG. 9B is a view showing a flight state of the capsule after reentry. is there. As shown in FIG. 9, the seventh embodiment has an acceleration sensor 10 inside the airframe of the sixth embodiment. In the seventh embodiment, after re-entry into the atmosphere, the deceleration acceleration detected by the acceleration sensor 7 maintains a substantially constant value, and the angular velocity of the airframe detected by the angular velocity sensor 10 and the attitude angle integrated and calculated in the control device 8 are In order to stabilize the speed reduction plate 5 and the braking film 5
The controller 8 individually controls the expansion amount of the brake film 11 and the braking film 11.
Since the expansion amount can be controlled individually, the capsule can fly stably and the acceleration can be easily controlled.

[0034]

According to the first to seventh embodiments of the present invention, by changing the aerodynamic shape of the capsule after the atmospheric re-entry capsule re-entry into the atmosphere, the flight speed of the capsule is controlled as much as possible. Decelerates in the high rise, resulting in reduced aerodynamic heating and deceleration acceleration on the capsule.

[Brief description of drawings]

FIG. 1 is a diagram showing an atmosphere reentry capsule according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a pattern of acceleration and aerodynamic heating amount after reentry of the atmosphere in the atmosphere reentry capsule according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an atmosphere reentry capsule according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a pattern of acceleration and aerodynamic heating amount after reentry of the atmosphere of the atmosphere reentry capsule according to the second embodiment of the present invention.

FIG. 5 is a view showing an atmosphere re-entry capsule according to Embodiment 3 of the present invention.

FIG. 6 is a view showing an atmosphere re-entry capsule according to Embodiment 4 of the present invention.

FIG. 7 is a view showing an atmosphere re-entry capsule according to a fifth embodiment of the present invention.

FIG. 8 is a view showing an atmosphere re-entry capsule according to Embodiment 6 of the present invention.

FIG. 9 is a view showing an atmosphere re-entry capsule according to Embodiment 7 of the present invention.

FIG. 10 is a view showing a conventional atmosphere reentry capsule.

FIG. 11 is a diagram showing an example of a pattern of acceleration and aerodynamic heating amount of a conventional atmosphere reentry capsule after reentry into the atmosphere.

[Explanation of symbols] 1 capsule, 2 hypersonic air flow, 3 shock wave, 4 high temperature air flow, 5 speed reducer, 6 actuator, 7 acceleration sensor, 8 control device, 9 control line, 10 angular velocity sensor, 11 braking film, 12 slit Incoming braking film.

Claims (7)

[Claims] 1. An atmosphere re-entry capsule that re-enters the atmosphere from an orbit around the earth and is recovered on the ground,
In orbit around the earth, a plurality of deceleration plates housed on the side surface of the airframe and an actuator for deploying the deceleration plates from the surface of the airframe according to a predetermined sequence after reentry into the atmosphere are provided. . 2. The atmosphere reentry capsule according to claim 1, further comprising an acceleration sensor and an actuator control device for controlling the expansion amount of the deceleration plate from the body surface according to the detected deceleration acceleration value. . 3. An aircraft body angular velocity sensor, the detected angular velocity of the aircraft body, and the integrated attitude value of the attitude angle are used to individually control the amount of expansion of the reduction plate from the aircraft body surface so that the aircraft can fly in a desired attitude. 3. The atmospheric reentry capsule according to claim 2, further comprising a control device for the actuator. 4. The atmosphere re-entry capsule according to claim 1, wherein a braking film is provided between the adjacent speed reducing plates. 5. The atmosphere re-entry capsule according to claim 4, wherein a slit in the circumferential direction is provided in the braking film between the adjacent deceleration plates. 6. An acceleration sensor, and an actuator control device for controlling the expansion amount of the control film between the speed reducer plate and the speed reducer plate from the body surface according to the value of the detected deceleration acceleration. Atmosphere re-entry capsule described. 7. A desired attitude is obtained by individually controlling the amount of expansion of the braking film between the speed reducer plate and the speed reducer plate from the surface of the machine body by means of the machine body angular velocity sensor, the detected angular velocity of the machine body, and the value of the posture angle obtained by integral calculation. 7. An atmosphere re-entry capsule according to claim 6, further comprising a control device for an actuator for flying in the air.