JP2643551B2 - Ramjet engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention]

(Industrial application field) The present invention relates to an improvement of a ramjet engine. (Prior Art) Conventionally, as a ramjet engine, as shown in FIG.
An air intake device (air intake passage) including an intake 130a and a diffuser 103b between the center body 102 and the outer cylinder 101.
In some cases, a 103 is provided, a combustor 104 is provided at a rear portion of the central body 102, and a jet nozzle 105 is provided at a rear end portion of the outer cylinder 101. Such a ramjet engine is described in, for example, Showa 58
"Aerospace Engineering Handbook / Enhanced Edition" published by Maruzen in January, 1998
608 and 609. In this type of ramjet engine, the central body 10
2, equipped with a combustion supply system and an injection device,
By providing a control device for the flow rate of the fuel to be injected, the thrust is changed by adjusting the flow rate of the fuel according to the requirements of the flight altitude and the speed. (Problems to be Solved by the Invention) However, in the above-described conventional ramjet engine, each of the shapes and dimensions of the air intake device 103, the combustor 104, and the jet nozzle 105 is constant. Therefore, although the structure is simple, the effective operation speed range is 2
Under the operating conditions that are limited to a small range of about 3 Mach and deviate from design conditions, a strong air vibration (buzz) is likely to occur due to a decrease in the amount of inflow air, and the total pressure is recovered due to an increase in the amount of inflow air. Or the rate drops sharply. Therefore, it is difficult for the conventional ramjet engine to operate in a wide speed range or to cope with a sudden change in speed, and thus has a problem in improving performance. (Object of the Invention) The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide a ramjet engine capable of significantly improving operational performance.

Configuration of the Invention

(Means for Solving the Problems) A ramjet engine according to the present invention comprises, as a first aspect of the present invention, a ramjet equipped with an air intake device, a combustor capable of controlling a fuel flow rate, and a jet nozzle. In the engine, the air intake device has a first guide portion along the outer surface side of the engine main body, a second guide portion continuously reaching the combustor at a rear end thereof, and a control plate which is moved in the front-rear direction by the actuator. A rear end portion is rotatably connected to the engine main body in a state facing the control plate, and an inclined plate is rotated by the actuator in a direction approaching and separating from the control plate. Thus, a compression channel opened forward and a diffusion channel continuous through the throat portion behind the compression channel are formed, and a critical operating state near the throat portion is detected to detect the control plate and the control plate. A ramjet engine having an air intake device, a combustor capable of controlling a fuel flow rate, and a jet nozzle. , The jet nozzle is composed of a block divided into two in the diameter direction, one of the blocks is movable in the front-rear direction by an actuator, the other block is fixed to the engine body, the air intake device, A control plate having a first guide portion along the outer surface side of the engine body and a second guide portion continuously reaching the combustor at a rear end thereof and moving in the front-rear direction by an actuator; A rear end portion is rotatably connected to the engine body side, and an inclined plate that is rotated by an actuator in a direction approaching and separating from the control plate is provided. In between, a compression channel opened forward and a diffusion channel continuous through a throat portion behind the compression channel are formed, and a critical operating state near the throat portion is detected to control the control plate, It is provided with a detecting means for controlling the plate and one of the blocks, and each of the above-mentioned structures serves as means for solving the problem. (Effect of the Invention) In the ramjet engine according to claim 1 of the present invention, an upright shock wave is located slightly downstream of the throat portion of the air intake device in response to acceleration / deceleration due to fuel flow rate adjustment or the like. State, or a state in which the flow velocity in the throat section is 1.2 to 1.3 Mach, that is, while maintaining the critical operation state, while detecting the critical operation state by the detecting means, the control plate is moved in the front-rear direction by the actuator and tilted. The air intake area and the opening area of the throat portion are changed by rotating the plate in a direction approaching and separating from the control plate by an actuator to adjust the amount of inflow air. In a ramjet engine, one of the blocks that make up the nozzle is moved in the front-rear direction by an actuator along with the operation of the control plate and the inclined plate. , The opening area of the nozzle throat portion is also changed, so that the flow rate matching between the inflow air and the outflow gas from the jet nozzle is always maintained. First Embodiment Hereinafter, a first embodiment of the present invention based on claim 1 will be described with reference to the drawings. That is, the ramjet engine is mounted on a supersonic flying vehicle 1 as shown in FIG. 1, and an air intake device 2 opening at a lower part of the fuselage of the flying vehicle 1 and a fuel injection device capable of controlling a flow rate (see FIG. 1). (Not shown), and a jet nozzle 4. The air intake device 2 includes a control plate 5 and an inclined plate 6 facing the lower side thereof. The control plate 5 is continuous with a first guide portion 5a parallel to the flow of air along the lower surface of the flying body 1 on the outer surface side of the engine body and at a predetermined angle upward from its rear end. Second guide 5b leading to combustor 3
The flying object 1 can be moved in the front-rear direction by the actuator 7. The rear end of the inclined plate 6 is rotatably connected to the outer wall 1a of the flying object 1 on the engine body side, and the direction in which the actuator 8 approaches and separates from the control plate 5 (vertical direction). The angle can be adjusted with respect to the flow direction of the air by rotating the airbag. The inclined plate 6 forms an air inlet 6a opened forward with the control plate 5, and the sectional area between the inclined plate 6 and the first guide portion 5a gradually decreases in the air flow direction. A compression channel 9 and a throat portion 10 which is a rear end portion thereof are formed, and a diffusion channel 11 having a sectional area gradually increasing toward the combustor 3 is continuously formed downstream of the throat portion 10. doing. That is, in the air intake device 2 of this embodiment, the control plate 5, the inclined plate 6, and each of the actuators 7, 8 change the air capture area at the air intake 6a and the opening area of the throat portion 10 in the inflow path driving mechanism. Is composed. The second guide portion 5b of the control plate 5 is set slightly downstream of the throat portion 10 as detecting means for detecting a critical operation state near the throat portion and controlling the control plate 5 and the inclined plate 6. In this position, two upright shock wave sensors 12 are provided in the front-back direction of the flow to detect the position of upright shock waves generated during operation. Next, the operation of the ramjet engine in a uniform flow will be described. The ramjet engine is
The total operation Mach range is set to 2 to 5, and the limit Mach number at the fuel equivalent ratio φ = 1.0 of the maximum combustion load is set to 3.5. The supersonic airflow flows parallel to the lower surface of the flying object 1.
Therefore, by the actuator 8, the inclined plate 6 is set to an inclination angle δ which is adapted to the flow rate of air, oblique shock wave S ₁ from the leading edge first of the inclined plate 6 is generated. The air that has passed through the first oblique shock wave S ₁ changes its direction at an argument equal to the inclination angle δ, flows in parallel with the inclination plate 6, and is decelerated and compressed. a second oblique shock wave S ₂ is generated in the first guide portion 5a. In this way, within the compression channel 9, continuously generated in a state that reflects an oblique shock wave S ₁ to S _3, it slows the inflow air in these oblique shock waves S ₁ to S _3, and and compressed Pass through throat section 10. At this time, the opening area of the throat section 10 is adjusted by moving the control plate 5 by the actuator 7 so that the flow velocity in the throat section 10 becomes about 1.2 to 1.3 Mach. In the diffusion channel 11, an upright shock wave _SN is generated slightly downstream of the throat portion 10 by acceleration / expansion of air accompanying the passage of the throat portion 10, and the air is decelerated to the subsonic range through the upright shock wave _SN . At the same time, it is compressed and supplied to the combustor 3. Further, in the diffusion channel 11, an upright shock wave sensor
At 12, the position of the upright shock wave _SN is detected, thereby determining that the air intake device 2 is in a critical operating state. Further, the ramjet engine injects fuel into the supplied air in the combustor 3 to continuously burn the air,
The combustion gas is ejected from the jet nozzle 4 to obtain a thrust. Here, the air intake device 2 is provided with an inclination angle δ of the inclined plate 6.
When the inflow air amount increases with the constant, the oblique shock wave angle decreases, the number of oblique shock waves decreases, and the upright shock wave S _N
Is in a retreating supercritical operating state. Therefore, when the ramjet engine increases the thrust for a sudden operation such as a large acceleration rise, the fuel flow rate is increased, the fuel equivalence ratio is set to near 1.0, and the temperature of the combustion gas is increased. While detecting the position of the upright shock wave _SN with the upright shock wave sensor 12, the inclination angle δ of the inclined plate 6 is increased to increase the air capture area. Thereby, the number of oblique shock waves is maintained or increased, and the opening area of the throat portion 10 is adjusted by moving the control plate 5 so that the flow velocity in the throat portion 10 does not change. When decelerating, the inclination angle of the inclined plate 6 is reduced to adjust the amount of inflow air that can maintain the critical operation state. As described above, the ramjet engine takes in air that matches the gas flow rate that can flow out of the jet nozzle 4 when the Mach number is below the limit Mach number (3.5).
Is always kept in a critical operating state, and even if sudden acceleration or deceleration is performed, air vibration does not occur and the total pressure recovery rate does not suddenly stop, and the air intake device has a constant structure. Compared to one conventional ramjet engine, the second
As shown by the dashed line in the figure, when the speed exceeds about 3 Mach, as compared with the conventional ramjet engine in which the degree of reduction of the total pressure recovery rate becomes sharper, as shown by the solid line in FIG. The degree of decrease in the total pressure recovery rate is extremely small. In addition, the ramjet engine has a limit Mach number (3.
Beyond 5), a supercritical state is established, and the degree of reduction in the total pressure recovery rate increases, but the total pressure recovery rate is clearly higher than that of the conventional ramjet engine. (Second Embodiment) A second embodiment according to claim 2 of the present invention will be described. The ramjet engine in this embodiment is mounted on a supersonic flying object 21 shown in FIG. 3, and has an air intake device 2 opening at a lower portion of the flying object 21 at the lower body, and a fuel injection device capable of controlling a flow rate (see FIG. 3). (Not shown), and a jet nozzle 24. The air intake device 2 has substantially the same configuration as that of the previous embodiment. The jet nozzle 24 is divided into upper and lower blocks 24a and 24b, and the upper block is
24a is movable in the front-back direction of the flying object 21, and the lower block 24b is fixed. That is, in the jet nozzle 24 of this embodiment, the upper block 24a and the actuator 13 constitute a nozzle drive mechanism that changes the opening area of the nozzle throat section 14. Next, the operation of the ramjet engine in a uniform flow will be described. The supersonic airflow flows parallel to the lower surface of the flying object 21.
Therefore, when the inclined plate 6 is set to the inclination angle δ suitable for the flow velocity of the air by the actuator 8, the oblique shock waves S _{1 to} S ₃ are continuously generated in the compression channel 9 while reflecting the oblique shock waves S _{1 to} S _3. The inflow air is decelerated by the shock waves S _{1 to} S ₃ , compressed and passed through the throat unit 10. At this time, the opening area of the throat section 10 is adjusted by moving the control plate 5 by the actuator 7 so that the flow velocity in the throat section 10 becomes about 1.2 to 1.3 Mach. In the diffusion channel 11, the air is decelerated to a subsonic range through an upright shock wave _SN generated slightly downstream of the throat portion 10, and is compressed and supplied to the combustor 3. Further, in the diffusion channel 11, the position of the upright shock wave _SN is detected by the upright shock wave sensor 12, whereby it is determined whether the air intake device 2 is in a critical operation state or a supercritical operation state. doing. Further, in the combustor 3, the fuel is injected into the supplied air to continuously burn the fuel. In the jet nozzle 24, when the high-temperature gas is expanded to the atmospheric pressure, an actuator is used.
The upper block 24a is moved at 13 and the nozzle throat section 14
By adjusting the opening area of the ramjet engine, flow matching between the inflow air and the outflow gas of the ramjet engine is maintained. In this manner, the ramjet engine always maintains the critical operation state of the air intake device 2 by the flow rate matching, and stably maintains the high total pressure recovery rate. Further, as described in the first embodiment, when the inclination angle δ of the inclined plate 6 is constant and the amount of inflow air increases, the air intake device 2 decreases the oblique shock wave angle and reduces the number of oblique shock waves. And the upright shock wave _SN recedes. For this reason, when the speed of the flying object 21 increases with a constant fuel flow rate, the inclination angle δ of the inclined plate 6 is increased while the position of the upright shock wave _SN is detected by the upright shock wave sensor 12, and the intake angle is increased. 6a, the number of oblique shock waves is maintained or increased, the control plate 5 is retracted to reduce the opening area of the throat portion 10, and the jet nozzle 24
The opening area of the nozzle throat portion 14 is reduced. Thereby, the flow rate matching between the inflow air and the outflow gas and the critical operation state of the air intake device 2 are maintained. The above operation is the same when the fuel flow rate is reduced. Further, when the thrust is increased due to a sudden movement such as a large acceleration rise, the fuel flow rate is increased, and the fuel equivalent ratio is set to near 1.0 to increase the temperature of the combustion gas. Increases the opening area of the nozzle throat portion 14 of the jet nozzle 24 prior to an increase in the fuel flow rate,
By controlling while detecting the upright shock wave sensor 12 so that the upright shock wave _SN is slightly retracted from the cruising position, the operation is performed in a somewhat overstable state so that the operation is performed more reliably. Is good. In addition, as the thrust increases, the inclination angle δ of the inclined plate 6 increases, and the control plate 5
By adjusting the opening area of the throat portion 10 as appropriate, while maintaining the flow rate matching between the inflow air and the outflow gas,
The air intake device 2 is brought into a critical operation state. In this way, the ramjet engine can always obtain a critical operation state by controlling the air intake device 2 and the jet nozzle 24 in all operation requests such as cruising and acceleration / deceleration, and even if rapid acceleration / deceleration is performed. In addition, there is no occurrence of air vibration or a sudden decrease in the total pressure recovery rate.
Also, as compared with a conventional ramjet engine in which the air intake device and the jet nozzle have a fixed structure, as shown by a broken line in FIG. In contrast to the conventional ramjet engine in which the degree of the pressure recovery rate sharply increases, the degree of the decrease in the total pressure recovery rate with the increase in the speed is extremely small as shown by the solid line in FIG. A high total pressure recovery rate can be stably maintained even in a speed range above Mach. In general, when a hydrocarbon fuel such as jet fuel or liquefied natural gas is used, in a low Mach region that does not greatly exceed 3 Mach, the combustor inlet air pressure is 0.3 kg / cm ² A or less, and the combustor inlet air When the temperature is lower than 1000 K, the combustion efficiency may suddenly decrease and the operation may become inoperable. In the ramjet engine, however, the air intake device 2 operates by forming multiple shock waves corresponding to the flight Mach number. In addition, since the critical operation state is always maintained, there is no concern that the above-mentioned limit of the combustion efficiency is broken even in a low Mach range or a high altitude (for example, 35 km). Further, the ramjet engine enlarges the air capture area by increasing the inclination angle δ of the inclined plate 6 with an increase in speed. However, at a predetermined Mach number or more, excessive force adversely affects the engine and the body. It is preferable to keep the inclination angle δ and the air capture area constant in order to avoid the danger of giving In this case, the thrust coefficient slightly decreases with an increase in the Mach number, but since the Mach number is already large, the surplus thrust decreases very little and there is almost no decrease in acceleration. In each of the above embodiments, the upright shock wave sensor 12 is used as the detection means, but the critical operation state may be determined using an air speed meter in the throat section 10.

【The invention's effect】

As described above, according to the ramjet engine according to claim 1 of the present invention, the control plate and the inclined plate for changing the air capture area by the compression flow path and the opening area of the throat portion; Detecting means for detecting the critical operation state near the throat section and controlling the control plate and the inclined plate, particularly in the speed region below the limit Mach number set by the gas flow rate etc. which can flow out of the jet nozzle, etc. Can always maintain a high total pressure recovery rate in a critical operation state, and a combination of a control plate that moves in the front-rear direction and an inclined plate that rotates in a direction approaching and separating from the control plate, It is possible to individually adjust the air capture area and the opening area of the throat section, for example, it is possible to accurately perform control such as keeping the flow rate of the throat section constant. , Thereby, stable operation is obtained on top that can be operated at a wide speed range than the conventional ramjet engine, this addition can be obtained thrust coefficient and specific high value thrust both. Further, according to the ramjet engine according to claim 2 of the present invention, the control plate, the inclined plate, the detecting means,
In addition, the jet nozzle that moves one block to change the opening area of the nozzle throat portion can obtain the same effect as the first item, and can also be used during cruising or acceleration / deceleration due to fuel flow rate adjustment. In any situation, the flow rate in the engine can be maintained and the air intake device can be kept in critical operation to maintain a high total pressure recovery rate, thereby further expanding the operable speed range. The cruising at a high Mach number and a high altitude can also significantly improve the specific distance characteristic (cruising ability), and can greatly improve the overall operation performance. In addition, by employing a jet nozzle that moves one of the two divided blocks, adjustment of the opening area of the nozzle throat can be realized with a simple configuration, which can contribute to weight reduction and the like.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a ramjet engine according to a first embodiment of the present invention together with a flying object, and FIG. 2 is a total pressure recovery with an increase in the speed of the ramjet engine according to the first embodiment. Graph showing change in rate, third
FIG. 4 is a cross-sectional view showing a ramjet engine according to a second embodiment of the present invention together with a flying object, and FIG. 4 is a sectional view of a total pressure recovery rate with an increase in the speed of the ramjet engine according to the second embodiment. FIG. 5 is a sectional view illustrating a conventional ramjet engine. 2 ... air intake device, 3 ... combustor, 4, 24 ... jet nozzle, 5 ... control plate, 6 ... inclined plate, 7, 8, 13 ... actuator, 9 ... compression channel, 10 …… (at the air intake)
Throat section, 11 diffusion channel, 12 upright shock wave sensor (detection means), (5, 6, 7, 8 ... inflow path drive mechanism), 14 ...
Nozzle throat part, 24a ... upper block (of nozzle), (13, 24a ... nozzle driving mechanism).

Claims (2)

(57) [Claims] 1. A ramjet engine having an air intake device, a combustor capable of controlling a fuel flow rate, and a jet nozzle, wherein the air intake device has a first guide portion along an outer surface of an engine body. A control plate having a second guide portion at a rear end thereof and continuing to the combustor and moving in the front-rear direction by an actuator; and a rear end portion rotatable toward the engine body in a state facing the control plate. An inclined plate which is connected to the actuator and pivots in a direction of approaching / separating from the control plate by an actuator; a compression passage opened forward between the control plate and the inclined plate; and a throat portion provided behind the compression passage. A ramjet engine comprising: a detection means for forming a continuous diffusion flow path through a through hole, detecting a critical operation state near a throat portion, and controlling a control plate and an inclined plate. 2. A ramjet engine equipped with an air intake device, a combustor capable of controlling the flow rate of fuel, and a jet nozzle, wherein the jet nozzle comprises a block divided into two in the diameter direction, and one of the blocks is divided into two blocks. Is movable in the front-rear direction by an actuator, the other block is fixed to the engine body, and the air intake device continuously burns the first guide portion along the outer surface side of the engine body and the rear end thereof. A control plate having a second guide portion leading to the vessel and moving in the front-rear direction by an actuator, and a rear end portion rotatably connected to the engine body side in a state facing the control plate, and connected to the control plate by the actuator. A compression passage that opens forward between the control plate and the inclination plate, and a throat behind the compression passage. Forming a diffusion channel which continuously through the ram jet engine, characterized in that it comprises a detection means for controlling the control plate by detecting a critical operating condition in the vicinity of the throat portion, the inclined plate and the one block.