An S-bend nozzle rear deck adjustment mechanism and an adjustment method for maintaining jet level

Abstract

The invention discloses an S-bend nozzle rear deck adjustment mechanism and an adjustment method for maintaining the jet level, which belongs to the field of aircraft engines; it includes an S-bend nozzle, a rear deck, a rotating shaft and a jet adjustment system, wherein the rear deck is hinged to the lower edge of the S-bend nozzle outlet through a rotating shaft; the jet adjustment system includes a pressure probe, a collection line, a control center and a control line; a plurality of pressure probes are vertically installed on the lower surface of the rear deck, and the wall pressure signal is transmitted to the control center through the collection line, and the control center makes an analysis, and transmits the analysis result to the driving part of the rotating shaft through the control line, and then drives the rotating shaft to adjust the rotation angle of the rear deck, so that the rear deck pressure is equal to the ambient pressure, and the jet angle of the S-bend nozzle is 0, that is, it is in a horizontal state. The invention solves the problem in the prior art that the jet angle of the S-bend nozzle with a rear deck varies greatly under different working conditions.

Description

Technical Field

[0001] The invention belongs to the field of aviation engines, and in particular relates to an S-bend nozzle rear deck adjustment mechanism and an adjustment method for maintaining a jet level. Background Art

[0002] In order to realize the integrated structural design of the S-bend nozzle and the rear body of the aircraft, the lower wall of the S-bend nozzle outlet needs to be integrated with the rear body surface of the fuselage with a wing-body fusion layout, forming an S-bend nozzle structure with a rear deck. This structure can not only further enhance the stealth performance of the S-bend nozzle, but also significantly reduce the tail drag of the aircraft.

[0003] The study on the influence of the rear deck length on the flow characteristics of the double S-bend nozzle with the rear deck in "Propulsion Technology" shows that the S-bend nozzle structure with a fixed rear deck will cause the nozzle to produce a jet angle change of up to 14° under different working conditions, making the actual thrust line of the engine not completely coincide with the engine axis, resulting in axial thrust loss and causing deflection torque, which affects the aerodynamic layout of the aircraft and makes it difficult to control the aircraft. Summary of the invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the prior art, the present invention provides an S-bend nozzle rear deck adjustment mechanism and an adjustment method for maintaining the jet level, which monitors the rear deck pressure in real time through a control center, and controls the rotation of the rear deck according to the difference between the rear deck pressure and the ambient pressure, so that the jet is kept in a horizontal state under different working conditions, thereby solving the problem of large changes in the jet angle of the S-bend nozzle with a rear deck under different working conditions in the prior art.

[0006] The technical solution of the present invention is: an S-bend nozzle rear deck adjustment mechanism, characterized in that it comprises an S-bend nozzle, a rear deck, a rotating shaft and a jet adjustment system, wherein the rear deck is hinged to the lower edge of the S-bend nozzle outlet through the rotating shaft;

[0007] The jet regulating system controls the rotation angle of the shaft by analyzing the collected rear deck pressure signal, and then adjusts the rotation angle of the rear deck so that the rear deck pressure is equal to the ambient pressure and the jet angle of the S-bend nozzle is 0, that is, it is in a horizontal state.

[0008] A further technical solution of the present invention is: the jet regulation system includes a pressure probe, a data acquisition line, a control center and a control line; a plurality of pressure probes are vertically installed on the lower surface of the rear deck, and the wall pressure signal is transmitted to the control center through the data acquisition line, and the control center makes an analysis, and transmits the analysis result to the driving part of the shaft through the control line, thereby driving the shaft to adjust the rotation angle of the rear deck.

[0009] A further technical solution of the present invention is: the rotating shaft is fixedly connected to the rear deck and hinged to the lower edge of the S-bend nozzle outlet.

[0010] A further technical solution of the present invention is: the driving part is a motor or a steering gear, whose output shaft is connected to the rotating shaft, and the control center outputs a signal to control the action of the motor or the steering gear, and drives the rotating shaft to rotate at the same time.

[0011] A further technical solution of the present invention is that the plurality of pressure probes are distributed at equal intervals along the center line of the rear deck and are arranged perpendicular to the rear deck.

[0012] A further technical solution of the present invention is that the number of the pressure probes is 15-30.

[0013] A further technical solution of the present invention is: the rear deck is in the shape of a rectangular flat plate structure, and the axial length of the rear deck is 2-4 times the height of the S-bend nozzle outlet.

[0014] A further technical solution of the present invention is that the lower edge of the outlet cross section of the S-bend nozzle is a straight line, and the outlet cross section is in a rectangular, trapezoidal or triangular shape.

[0015] A method for adjusting an S-bend nozzle to maintain a horizontal jet flow, characterized in that:

[0016] First, the pressure probe collects the pressure signal of the rear deck and transmits the pressure signal to the control center through the collection line;

[0017] Then, the control center calculates and analyzes the received pressure signal, and transmits the control signal to the drive part of the shaft through the control line according to the result;

[0018] Finally, the driving part drives the shaft to rotate the rear deck;

[0019] When the rear deck pressure is greater than the ambient pressure, the driving part controls the shaft to drive the rear deck to rotate clockwise. The greater the difference between the rear deck pressure and the ambient pressure, the greater the rotation angle of the rear deck. The clockwise rotation of the rear deck will reduce the rear deck pressure. If the rear deck pressure is still greater than the ambient pressure at this moment, the rear deck will continue to be controlled to rotate clockwise. When the rear deck pressure is less than the ambient pressure, the rear deck will be controlled to rotate counterclockwise to increase the rear deck pressure until the rear deck pressure is equal to the ambient pressure and the jet is in a horizontal state.

[0020] Beneficial Effects

[0021] The beneficial effects of the present invention are as follows: the S-bend nozzle rear deck structure using the technical solution of the present invention can enhance the infrared and radar stealth performance of the nozzle by shielding the high-temperature engine components by the S-bend nozzle and the rear deck; the rear deck pressure is monitored in real time by a control center, and the rotation of the rear deck is controlled according to the difference between the rear deck pressure and the ambient pressure, so that the jet is kept in a horizontal state under different working conditions, thereby solving the problem of large changes in the jet angle of the S-bend nozzle with the rear deck under different working conditions in the prior art; the difficulty of the present invention is to establish the relationship between the rotation direction of the rear deck and the change in the rear deck pressure through the rear deck adjustment mechanism, and determine the control law of the rear deck rotation.

[0022] When the length of the rear deck is short, the effect of the rear deck on the jet angle is weak, while an increase in the length of the rear deck will cause a significant increase in the weight of the rear deck and increase the difficulty of control. Therefore, the present invention preferably sets the axial length of the rear deck to 2-4 times the height of the S-bend nozzle outlet.

[0023] The smaller the arrangement spacing of the pressure probes is, the better the control effect is. However, based on comprehensive considerations of cost saving and real-time detection effect, the present invention preferably sets the number of pressure probes to 15-30. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of an optional S-bend nozzle rear deck adjustment mechanism according to an embodiment of the present invention when the rear deck angle is 0°;

[0025] Figure 2 is a schematic diagram of an optional S-bend nozzle rear deck adjustment mechanism according to an embodiment of the present invention when the rear deck angle is 20°;

[0026] Figure 3 is a partial view of a rectangular nozzle of an optional S-bend nozzle rear deck adjustment mechanism according to an embodiment of the present invention;

[0027] Figure 4 It is a partial view of a trapezoidal nozzle of an optional S-bend nozzle rear deck adjustment mechanism according to an embodiment of the present invention;

[0028] Figure 5 It is a partial view of a triangular nozzle of an optional S-bend nozzle rear deck adjustment mechanism according to an embodiment of the present invention;

[0029] Figure 6 is a spray velocity cloud diagram of an optional S-bend nozzle rear deck adjustment mechanism when the rear deck is not adjusted according to an embodiment of the present invention;

[0030] Figure 7 is a jet velocity cloud diagram when an S-bend nozzle rear deck adjustment mechanism adopts an adjustment method of maintaining the jet level according to an optional embodiment of the present invention;

[0031] Explanation of the reference numerals: 1. S-bend nozzle; 2. rear deck; 3. rotating shaft; 4. pressure probe; 5. acquisition circuit; 6. control center; 7. control circuit; 8. nozzle outlet. DETAILED DESCRIPTION

[0032] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] The embodiment of the present invention provides an S-bend nozzle rear deck adjustment mechanism and an adjustment method for maintaining the jet level, such as Figure 1 , 2 As shown, it includes: an S-bend nozzle 1, a rear deck 2, a rotating shaft 3, a pressure probe 4, a collection line 5, a control center 6, and a control line 7. The lower edge of the S-bend nozzle outlet 8 is connected to the rear deck 2 at the rotating shaft 3 through a hinge. The wall pressure measured by the pressure probe 4 installed on the lower side of the rear deck 2 is input into the control center 6 through the collection line 5. When the pressure of the rear deck 2 is greater than the ambient pressure, the control center 6 controls the driving part of the rotating shaft 3 through the control line 7, and the driving part drives the rotating shaft 3 to drive the rear deck 2 to rotate clockwise. When the pressure of the rear deck 2 is less than the ambient pressure, the rear deck 2 is controlled to rotate counterclockwise until the pressure of the rear deck 2 is equal to the ambient pressure, and the jet angle of the S-bend nozzle 1 is 0, that is, it is in a horizontal state.

[0035] With the S-bend nozzle rear deck structure of the technical solution of the present invention, the shielding of the high-temperature engine components by the S-bend nozzle 1 and the rear deck 2 can enhance the infrared and radar stealth performance of the nozzle; the pressure of the rear deck 2 is monitored in real time by the control center 6, and the rotation of the rear deck 2 is controlled according to the difference between the pressure of the rear deck 2 and the ambient pressure, so that the jet is kept in a horizontal state under different working conditions, thereby solving the problem of large changes in the jet angle of the S-bend nozzle with the rear deck under different working conditions in the prior art.

[0036] Specifically, Figure 3 , 4 As shown in Figures 5 and 6, the lower edge of the cross section of the S-bend nozzle outlet 8 is a straight line, and the cross-sectional shape can be a rectangle, a trapezoid or a triangle.

[0037] like Figure 3 , 4 As shown in FIG. 5 , the shape of the rear deck 2 is a rectangle. When the length of the rear deck 2 is short, the influence of the rear deck 2 on the jet angle is weak. However, the increase of the length of the rear deck 2 will cause a significant increase in the weight of the rear deck 2, and the control difficulty will increase. Therefore, after repeated tests, the length of the rear deck 2 is 2-4 times the height of the S-bend nozzle outlet 8.

[0038] like Figure 1 , 2 As shown, the rotating shaft 3 is fixedly connected to the rear deck 2 and is hinged to the lower edge of the S-bend nozzle outlet 8. The rotation of the rotating shaft 3 can drive the rear deck 2 to rotate.

[0039] like Figure 1 , 2 As shown, the pressure probes 4 are evenly spaced along the center line of the rear deck 2 and are perpendicular to the rear deck 2; the smaller the spacing between the pressure probes 4, the better the control effect, but in order to save costs, the number of pressure probes 4 is 15-30.

[0040] like Figure 1 , 2 As shown, the control center 6 averages the pressure signal input by the acquisition line 5 in real time and calculates the pressure of the rear deck 2. When the pressure of the rear deck 2 is greater than the ambient pressure, the control line 7 controls the driving part of the shaft 3, and the driving part drives the shaft 3 to drive the rear deck 2 to rotate clockwise. The greater the difference between the pressure of the rear deck 2 and the ambient pressure, the greater the rotation angle of the rear deck 2. The clockwise rotation of the rear deck 2 will reduce the pressure of the rear deck 2. If the pressure of the rear deck 2 is still greater than the ambient pressure at this moment, the rear deck 2 will continue to be controlled to rotate clockwise. If the pressure of the rear deck 2 is less than the ambient pressure at this moment, the rear deck 2 will continue to be controlled to rotate counterclockwise to increase the pressure of the rear deck 2 until the pressure of the rear deck 2 is equal to the ambient pressure and the jet is in a horizontal state.

[0041] like Figure 6 , 7 As shown, when the nozzle pressure drop ratio is 4.65, the jet with an angle of 0° on the rear deck 2 deflects upward by 9.2°. At this time, the average pressure on the rear deck 2 is 1.4 times the ambient pressure. The rear deck 2 adjustment method proposed in the present invention is used to adjust the angle of the rear deck 2 to 10°. When the average pressure on the rear deck 2 is equal to the ambient pressure, the jet deflection angle is close to 0°, and the jet is in a horizontal state.

[0042] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. An S-bend nozzle rear deck adjustment mechanism, characterized in that: It comprises an S-bend nozzle, a rear deck, a rotating shaft and a jet regulating system, wherein the rear deck is hinged to the lower edge of the S-bend nozzle outlet through the rotating shaft; the rear deck is in the shape of a rectangular flat plate structure, and the axial length of the rear deck is 2-4 times the height of the S-bend nozzle outlet; the lower edge of the S-bend nozzle outlet cross section is a straight line, and the outlet cross section is in the shape of a rectangle, a trapezoid or a triangle; The jet flow regulating system controls the rotation angle of the rotating shaft by analyzing the collected rear deck pressure signal, and further adjusts the rotation angle of the rear deck so that the rear deck pressure is equal to the ambient pressure and the jet flow of the S-bend nozzle is in a horizontal state; The adjustment method for maintaining the jet level of the rear deck adjustment mechanism of the S-bend nozzle is as follows: first, a pressure probe collects a pressure signal of the rear deck, and transmits the pressure signal to a control center through an acquisition line; then, the control center calculates and analyzes the received pressure signal, and transmits a control signal to a driving part of the rotating shaft through a control line according to the result; finally, the driving part drives the rotating shaft to drive the rear deck to rotate; When the rear deck pressure is greater than the ambient pressure, the driving part controls the shaft to drive the rear deck to rotate clockwise. The greater the difference between the rear deck pressure and the ambient pressure, the greater the rotation angle of the rear deck. The clockwise rotation of the rear deck will reduce the rear deck pressure. If the rear deck pressure is still greater than the ambient pressure at this moment, the rear deck will continue to be controlled to rotate clockwise. When the rear deck pressure is less than the ambient pressure, the rear deck will be controlled to rotate counterclockwise to increase the rear deck pressure until the rear deck pressure is equal to the ambient pressure and the jet is in a horizontal state.

2. The S-bend nozzle rear deck adjustment mechanism according to claim 1, characterized in that: The jet regulation system includes pressure probes, data acquisition lines, a control center and a control line; a number of pressure probes are vertically installed on the lower surface of the rear deck, and the wall pressure signals are transmitted to the control center through the data acquisition lines. The control center makes an analysis and transmits the analysis results to the driving part of the shaft through the control line, thereby driving the shaft to adjust the rotation angle of the rear deck.

3. The S-bend nozzle rear deck adjustment mechanism according to claim 2, characterized in that: The rotating shaft is fixedly connected to the rear deck and is hinged to the lower edge of the S-bend nozzle outlet.

4. The S-bend nozzle rear deck adjustment mechanism according to claim 3, characterized in that: The driving part is a motor or a steering gear, whose output shaft is connected to the rotating shaft. The control center outputs a signal to control the action of the motor or the steering gear, and drives the rotating shaft to rotate at the same time.

5. The S-bend nozzle rear deck adjustment mechanism according to claim 2, characterized in that: The plurality of pressure probes are distributed at equal intervals along the center line of the rear deck and are arranged perpendicular to the rear deck.

6. The S-bend nozzle rear deck adjustment mechanism according to claim 5, characterized in that: The number of the pressure probes is 15-30.

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