Ejecting type ultra-wide flow regulation range low-noise wind tunnel power section and working method

Abstract

The invention discloses an injection type ultra-wide flow regulation range low-noise wind tunnel power section and a working method, and the wind tunnel power section comprises an air inlet, an inner duct, a small fan, a large fan, a non-full-circumference supporting structure, an actuator outer slide way, an on-off execution pipe section, an outer duct, an air outlet and other structures. Based on the design scheme of the wind tunnel power section of the large and small fan combined parallel structure and the working mode of the wind tunnel power section for realizing the on-off of the flow channels of the large and small fans by adopting the on-off execution pipe section, the pneumatic parameters of the wind tunnel can be continuously measured in an ultra-wide flow range under the condition that the wind tunnel power section is not replaced; and low-energy low-speed air in the outer duct and air in the inner duct are introduced through the ejector structure for mixed flowing, so that the flow speed and the noise level of an outlet of the wind tunnel are reduced, the noise propagation range is greatly reduced, and the device and the working method have the advantages of being low in flow resistance, low in noise, easy and convenient to operate, time-saving and labor-saving and the like.

Description

Technical Field

[0001] The invention relates to the technical field of gas delivery or wind tunnel velocity measurement, and in particular to an ejection-type ultra-wide flow regulation range low-noise wind tunnel power section and a working method. Background Art

[0002] Wind tunnel is one of the important metrological equipment for simulating specific flow fields and conducting basic parameter measurements such as flow velocity measurement. Among them, the power section of the wind tunnel is usually composed of a single fan and a pipe wall connected to the wind tunnel. Due to the narrow flow range of the fan itself, in order to expand the flow range of the wind tunnel, the traditional method requires the use of two or more wind tunnel power sections with different flow ranges. When using two or more wind tunnel power sections with different flow ranges, it is necessary to shut down the fan of the running wind tunnel power section, then move the original wind tunnel power section away, and then move in the new wind tunnel power section to connect with the wind tunnel, and finally start the new wind tunnel power section to complete the measurement of relevant aerodynamic parameters of the wind tunnel. However, the wind tunnel power section is large in size and heavy in weight. The above process of replacing the wind tunnel power section is not only time-consuming and labor-intensive, but also the measurement can only be stopped during the replacement of the wind tunnel power section, and it is impossible to achieve continuous measurement of aerodynamic parameters in the wind tunnel when the ultra-wide flow range continues to change. Therefore, wind tunnel testers have been unable to carry out continuous measurements over an ultra-wide flow range. In addition, when wind tunnel testers carry out measurements over an ultra-wide flow adjustment range, the wind tunnel will generate noise of 95 decibels or more, and the noise propagation range is large, affecting the physical and mental health of testers and staff around the wind tunnel. The ultra-wide flow range continuous measurement technology of the above wind tunnel and the noise reduction problem of the wind tunnel power section have seriously troubled testers and wind tunnel designers. At present, there is no mature technical solution to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide an ejection-type wind tunnel power section with ultra-wide flow regulation range and low noise and a working method in order to solve the above-mentioned problems.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] The power section of an ejection-type ultra-wide flow regulation range low-noise wind tunnel comprises an air inlet (1), an outer wall of an inlet section (2), an outer wall of a large fan inlet (3), an outer wall of a large fan support section of a power section (4), an outer wall of an inner channel outlet section (5), an ejection-type inner channel air outlet (6), a small fan (7), a large fan (8), a non-full-circumference support structure (9), an actuator outer slideway (10), an on-off actuator pipe section (11), an outer duct inlet (12), an outer duct (13), an outer duct outlet (14), a conveying channel from the outer duct to the inner channel (15), and a conveying channel from the inner channel to the outer duct (16), wherein the air inlet (1) is connected to the outer wall of the inlet section (2), the outer wall of the large fan inlet (3) is connected to the outer wall of the large fan support section of the power section (4), and the inner channel (16) is connected to the outer wall of the inner channel. The outer wall (5) of the duct outlet section is connected to the outer wall (4) of the large fan support section of the power section, the outer duct to inner duct delivery channel (15) and the inner duct to outer duct delivery channel (16) are connected to the outer wall (5) of the inner duct outlet section, the ejection type inner duct air outlet (6) is connected to the outer duct to inner duct delivery channel (15) and the inner duct to outer duct delivery channel (16), the outer duct inlet (12) is connected to the outer duct (13), the outer duct outlet (14) is connected to the outer duct (13), the large fan guide vane fixing ring (84) is fixed on the inner side of the outer wall (4) of the large fan support section of the power section, and the small fan (7) includes a small fan inlet guide structure (71), a small fan blade (72), a small fan guide vane (73), a small fan guide vane fixing ring (74) and a small fan The fan motor (75) comprises a large fan inlet flow guide structure (81), a large fan rotor blade (82), a large fan guide blade (83), a large fan guide blade fixing ring (84), a large fan outlet flow guide structure (85) and a large fan motor (86). The large fan motor (86) is respectively connected to the large fan inlet flow guide structure (81), the large fan rotor blade (82), the large fan guide blade (83) and the large fan outlet flow guide structure (85). The small fan motor (75) is respectively connected to the small fan inlet flow guide structure (71), the small fan rotor blade (72), the small fan guide blade (73), the small fan guide blade fixing ring (74) and the large fan inlet flow guide structure (81). The axial cross-sectional area of ​​the outer wall (2) of the inlet section is from the inlet to the outlet. The axial cross-sectional area of ​​the large fan inlet outer wall (3) shows a trend of continuous increase from the inlet to the outlet, and the axial cross-sectional area of ​​the inner channel outlet section outer wall (5) shows a trend of continuous increase from the inlet to the outlet. The non-full-circumference support structure (9) is fixed at the position where the inlet section outer wall (2) and the large fan inlet outer wall (3) are connected. The actuator outer slideway (10) is fixed to the non-full-circumference support structure (9). The non-full-circumference support structure (9) is a non-full-circumference closed support structure through which gas can pass. The on-off actuator pipe section (11) is limited to move axially in the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74), and can reach the wall surface of the inlet section outer wall (2) or the wall surface of the large fan inlet guide structure (81).The maximum flow value of the flow range of the small fan (7) is greater than the minimum flow value of the flow range of the large fan (8).

[0006] The working method of the power section of the induced-type ultra-wide flow regulation range low-noise wind tunnel includes a small fan working condition and a large fan working condition. The small fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the inlet section outer wall (2). At this time, a part of the air flows in from the air inlet (1) of the induced-type ultra-wide flow regulation range low-noise wind tunnel power section, flows through the space surrounded by the front wall surface of the inlet section outer wall (2) and the inner wall surface of the on-off execution pipe section (11) and the outer wall surface of the small fan inlet guide structure (71), enters the small fan blades (72) and the small fan guide vanes (73) of the small fan (7) to accelerate, and then flows out from the outer side of the wall surface of the large fan inlet guide structure (81), and successively enters the stationary large fan blade area (82), The air flows into the area surrounded by the guide vanes (83) of the large fan, the area surrounded by the inner wall surface of the outer wall (5) of the inner duct outlet section and the outer wall surface of the guide structure (85) at the outlet of the large fan, the area surrounded by the inner wall surface of the outer duct to inner duct transport channel (15) and the inner wall surface of the inner duct to outer duct transport channel (16), and then flows out from the ejection-type inner duct outlet (6). Another part of the air flows into the area surrounded by the front inner wall surface of the outer duct (13), the outer wall surface of the outer duct to inner duct transport channel (15), and the outer wall surface of the inner duct to outer duct transport channel (16) from the outer duct inlet (12), and then enters the area surrounded by the rear inner wall surface of the outer duct (13) together with the air flowing out from the ejection-type inner duct outlet (6). The two air flows are mixed to form one air flow, and then flows out from the outer duct outlet (14) to form the ejection-type ultra-wide flow adjustment range low noise wind tunnel power section;The large fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the large fan inlet guide structure (81). At this time, a part of the air flows in from the inlet (1) of the induced ultra-wide flow adjustment range low noise wind tunnel power section, flows through the inner side of the inlet section outer wall (2), the inner side of the large fan inlet outer wall (3), and the outer side of the small fan inlet guide structure (71), the outer side of the actuator outer slideway (10), and the outer side of the on-off execution pipe section (11), and enters the large fan blade (82) area and the large fan guide vane (83) area in turn, and accelerates to enter the inner wall surface of the inner channel outlet section outer wall (5) and the large fan outlet guide structure (8 5), the area surrounded by the outer wall surface of the outer duct to inner duct conveying channel (15) and the area surrounded by the inner wall surface of the inner duct to outer duct conveying channel (16), and then flows out from the ejection type inner duct outlet (6), and the other part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall surface of the outer duct (13), the outer wall surface of the outer duct to inner duct conveying channel (15), and the outer wall surface of the inner duct to outer duct conveying channel (16), and then enters the area surrounded by the rear inner wall surface of the outer duct (13) together with the air flowing out from the ejection type inner duct outlet (6), and the two air flows are mixed to form one air flow, and then flows out from the ejection type ultra-wide flow adjustment range low noise wind tunnel power section from the outer duct outlet (14). ;

[0007] The beneficial effects of the present invention are:

[0008] At present, there is no mature technical solution for a wind tunnel power section with an ultra-wide flow range and low noise that can be applied to continuously measure aerodynamic parameters. In view of the low noise, ultra-wide flow range, and the use conditions where the power section can be used without replacing the power section, the present invention proposes a low-cost, high-operability, and induced-type design of a wind tunnel power section with an ultra-wide flow adjustment range and low noise. The present invention uses an independently developed small fan with a flow adjustment capacity of 12 times and a large fan with a flow adjustment energy of 6 times. It adopts a design scheme based on a combined parallel structure of large and small fans. The on-off execution pipe section is creatively designed to control the on-off of the flow channels of the large and small fans, so that the working fluid forms two flow schemes through the wind tunnel power section. One is that the large fan is stationary, and the working fluid is only pressurized and accelerated by the work of the small fan. The other is that the small fan is stationary and completely isolated, and the working fluid is only pressurized and accelerated by the work of the large fan. Based on the above two forms, the flow adjustment of the small fan can be The flow range of the combined wind tunnel power section is superimposed with the flow adjustment range of the large fan, so that the maximum and minimum flow ratio of the combined wind tunnel power section is 63 times the ultra-wide flow adjustment range. Therefore, without replacing the power section, the wind tunnel can continuously measure the aerodynamic parameters in an ultra-wide flow range. Compared with the vertical or tilted movement opening and closing scheme, which greatly increases the flow resistance in the wind tunnel power section, thereby causing the actuator to swing, reduce the life of the actuator, and reduce the wind tunnel measurement accuracy, the horizontal movement of the actuator outer slide and the opening and closing scheme of the on-off actuator section are adopted. It is an aerodynamic solution that reduces the flow resistance in the power section of the wind tunnel to the minimum, eliminates the swing and damage of the actuator and the supporting structure caused by the Karman vortex street or the low-pressure unstable cyclone, and eliminates the influence of the Karman vortex street or the low-pressure unstable cyclone on the measurement accuracy of the wind tunnel. Therefore, the opening and closing solution of the horizontally movable actuator outer slideway and the on-off actuator pipe section is the solution with the lowest cost, high reliability and longest service life; in order to significantly reduce the noise level of the power section of the wind tunnel, the present invention adopts an ejector structure to introduce low-energy and low-speed air from the outer duct to mix with the inner duct air, thereby reducing the flow velocity and noise level of the wind tunnel outlet, significantly reducing the noise propagation range, and protecting the physical and mental health of the test personnel and the staff around the wind tunnel; in addition, in this solution, the axial cross-sectional area of ​​the outer wall of the inlet section shows a trend of continuous increase from the inlet to the outlet, the axial cross-sectional area of ​​the outer wall of the large fan inlet shows a trend of continuous decrease from the inlet to the outlet, and the axial cross-sectional area of ​​the outer wall of the outlet section shows a trend of continuous increase from the inlet to the outlet. The above structural design can significantly reduce the flow resistance of the power section of the wind tunnel, making the power section of the wind tunnel more energy-saving and more advanced in aerodynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the power section of the ejection-type ultra-wide flow regulation range low-noise wind tunnel of the present invention.

[0010] Figure 2It is a schematic diagram of the working state of the power section of the ejection type ultra-wide flow adjustment range low-noise wind tunnel of the present invention, wherein (a) is the working condition of a small fan, and (b) is the working condition of a large fan. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the accompanying drawings:

[0012] like Figure 1As shown, the power section of the induced-type ultra-wide flow regulation range low-noise wind tunnel comprises an air inlet (1), an inlet section outer wall (2), a large fan inlet outer wall (3), a power section large fan support section outer wall (4), an inner channel outlet section outer wall (5), an induced-type inner channel air outlet (6), a small fan (7), a large fan (8), a non-full-circumference support structure (9), an actuator outer slideway (10), an on-off actuator pipe section (11), an outer duct inlet (12), an outer duct (13), an outer duct outlet (14), an outer duct to inner duct transport channel (15), and an inner duct to outer duct transport channel (16), wherein the air inlet (1) is connected to the inlet section outer wall (2), the large fan inlet outer wall (3) is connected to the outer wall of the power section large fan support section (4), The outer wall (5) of the inner duct outlet section is connected to the outer wall (4) of the large fan support section of the power section, the outer duct to inner duct delivery channel (15) and the inner duct to outer duct delivery channel (16) are connected to the outer wall (5) of the inner duct outlet section, the ejection type inner duct air outlet (6) is connected to the outer duct to inner duct delivery channel (15) and the inner duct to outer duct delivery channel (16), the outer duct inlet (12) is connected to the outer duct (13), the outer duct outlet (14) is connected to the outer duct (13), the large fan guide vane fixing ring (84) is fixed on the inner side of the outer wall (4) of the large fan support section of the power section, and the small fan (7) includes a small fan inlet guide structure (71), a small fan blade (72), a small fan guide vane (73), and a small fan guide vane fixing ring (74) and a small fan motor (75), the large fan (8) comprising a large fan inlet guide structure (81), a large fan rotor blade (82), a large fan guide blade (83), a large fan guide blade fixing ring (84), a large fan outlet guide structure (85) and a large fan motor (86), the large fan motor (86) being respectively connected to the large fan inlet guide structure (81), the large fan rotor blade (82), the large fan guide blade (83) and the large fan outlet guide structure (85), the small fan motor (75) being respectively connected to the small fan inlet guide structure (71), the small fan rotor blade (72), the small fan guide blade (73), the small fan guide blade fixing ring (74) and the large fan inlet guide structure (81), the axial cross-sectional area of ​​the inlet section outer wall (2) from the inlet to the outlet The axial cross-sectional area of ​​the large fan inlet outer wall (3) shows a trend of continuously increasing from the inlet to the outlet, the axial cross-sectional area of ​​the inner channel outlet section outer wall (5) shows a trend of continuously increasing from the inlet to the outlet, the non-full-circumference support structure (9) is fixed at the position where the inlet section outer wall (2) and the large fan inlet outer wall (3) are connected, the actuator outer slideway (10) is fixed to the non-full-circumference support structure (9), the non-full-circumference support structure (9) is a non-full-circumference closed support structure through which gas can pass, the on-off actuator pipe section (11) is limited to move axially in the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74), and can reach the wall surface of the inlet section outer wall (2) or the wall surface of the large fan inlet guide structure (81),The maximum flow value of the flow range of the small fan (7) is greater than the minimum flow value of the flow range of the large fan (8).

[0013] As a preferred embodiment of the present invention, Figure 2As shown, the working method of the power section of the induced-type ultra-wide flow regulation range low-noise wind tunnel includes a small fan working condition and a large fan working condition. The small fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the inlet section outer wall (2). At this time, a part of the air flows in from the inlet port (1) of the induced-type ultra-wide flow regulation range low-noise wind tunnel power section, flows through the space surrounded by the front wall surface of the inlet section outer wall (2) and the inner wall surface of the on-off execution pipe section (11) and the outer wall surface of the small fan inlet guide structure (71), enters the small fan blade (72) and the small fan guide blade (73) of the small fan (7) to accelerate, and then flows out from the outer side of the wall surface of the large fan inlet guide structure (81), and successively enters the stationary large fan blade (82) area. The air flows out from the ejection-type inner duct outlet (6); another part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall of the outer duct (13), the outer wall of the outer duct to the inner duct transport channel (15), and the outer wall of the inner duct to the outer duct transport channel (16); and then flows out from the ejection-type inner duct outlet (6); the other part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall of the outer duct (13), the outer wall of the outer duct to the inner duct transport channel (15), and the outer wall of the inner duct to the outer duct transport channel (16); and then enters the area surrounded by the rear inner wall of the outer duct (13) together with the air flowing out from the ejection-type inner duct outlet (6); the two air flows are mixed to form one air flow, and then flows out from the ejection-type ultra-wide flow adjustment range low noise wind tunnel power section from the outer duct outlet (14);The large fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the large fan inlet guide structure (81). At this time, a part of the air flows in from the inlet (1) of the induced ultra-wide flow adjustment range low noise wind tunnel power section, flows through the inner side of the inlet section outer wall (2), the inner side of the large fan inlet outer wall (3), and the outer side of the small fan inlet guide structure (71), the outer side of the actuator outer slideway (10), and the outer side of the on-off execution pipe section (11), and enters the large fan blade (82) area and the large fan guide vane (83) area in turn, and accelerates to enter the inner wall surface of the inner channel outlet section outer wall (5) and the large fan outlet guide structure (8 5), the area surrounded by the outer wall surface of the outer duct to inner duct conveying channel (15) and the area surrounded by the inner wall surface of the inner duct to outer duct conveying channel (16), and then flows out from the ejection type inner duct outlet (6), and the other part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall surface of the outer duct (13), the outer wall surface of the outer duct to inner duct conveying channel (15), and the outer wall surface of the inner duct to outer duct conveying channel (16), and then enters the area surrounded by the rear inner wall surface of the outer duct (13) together with the air flowing out from the ejection type inner duct outlet (6), and the two air flows are mixed to form one air flow, and then flows out from the ejection type ultra-wide flow adjustment range low noise wind tunnel power section from the outer duct outlet (14). ;

[0014] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. The power section of the ejection type wind tunnel with ultra-wide flow adjustment range and low noise is characterized by: The invention comprises an air inlet (1), an outer wall of an inlet section (2), an outer wall of a large fan inlet (3), an outer wall of a large fan support section of a power section (4), an outer wall of an inner channel outlet section (5), an ejection-type inner channel air outlet (6), a small fan (7), a large fan (8), a non-full-circumference support structure (9), an actuator outer slideway (10), an on-off actuator pipe section (11), an outer duct inlet (12), an outer duct (13), an outer duct outlet (14), a conveying channel from the outer duct to the inner duct (15), and a conveying channel from the inner duct to the outer duct (16), wherein the air inlet (1) is connected to the outer wall of the inlet section (2), the outer wall of the large fan inlet (3) is connected to the outer wall of the large fan support section of the power section (4), the outer wall of the inner channel outlet section (5) is connected to the large fan support section of the power section (5), and the outer wall of the large fan outlet section (5) is connected to the large fan support section of the power section (6). The outer wall (4) of the fan support section is connected to the outer wall (4) of the fan support section, the outer duct to inner duct conveying channel (15) and the inner duct to outer duct conveying channel (16) are connected to the outer wall (5) of the inner duct outlet section, the ejection type inner duct outlet (6) is connected to the outer duct to inner duct conveying channel (15) and the inner duct to outer duct conveying channel (16), the outer duct inlet (12) is connected to the outer duct (13), the outer duct outlet (14) is connected to the outer duct (13), the large fan guide vane fixing ring (84) is fixed to the inner side of the outer wall (4) of the fan support section of the power section, the small fan (7) includes a small fan inlet guide structure (71), a small fan rotor blade (72), a small fan guide vane (73), a small fan guide vane fixing ring (74) and a small fan motor (75), and the large fan guide vane fixing ring (84) is fixed to the inner side of the outer wall (4) of the fan support section of the power section, the small fan (7) includes a small fan inlet guide structure (71), a small fan rotor blade (72), a small fan guide vane (73), a small fan guide vane fixing ring (74) and a small fan motor (75), The fan (8) comprises a large fan inlet flow guide structure (81), a large fan rotor blade (82), a large fan guide blade (83), a large fan guide blade fixing ring (84), a large fan outlet flow guide structure (85) and a large fan motor (86); the large fan motor (86) is respectively connected to the large fan inlet flow guide structure (81), the large fan rotor blade (82), the large fan guide blade (83) and the large fan outlet flow guide structure (85); the small fan motor (75) is respectively connected to the small fan inlet flow guide structure (71), the small fan rotor blade (72), the small fan guide blade (73), the small fan guide blade fixing ring (74) and the large fan inlet flow guide structure (81); the axial cross-sectional area of ​​the inlet section outer wall (2) increases continuously from the inlet to the outlet. The axial cross-sectional area of ​​the large fan inlet outer wall (3) shows a trend of continuously decreasing from the inlet to the outlet, and the axial cross-sectional area of ​​the inner channel outlet section outer wall (5) shows a trend of continuously increasing from the inlet to the outlet. The non-full-circumference support structure (9) is fixed at a position where the inlet section outer wall (2) and the large fan inlet outer wall (3) are connected. The actuator outer slideway (10) is fixed to the non-full-circumference support structure (9). The non-full-circumference support structure (9) is a non-full-circumference closed support structure through which gas can pass. The on-off actuator pipe section (11) is limited to move axially in the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74), and can reach the wall surface of the inlet section outer wall (2) or the wall surface of the large fan inlet guide structure (81).The maximum flow value of the flow range of the small fan (7) is greater than the minimum flow value of the flow range of the large fan (8).

2. The working method of the power section of the ejection type ultra-wide flow adjustment range low noise wind tunnel according to claim 1 is characterized in that: The working method includes a small fan working condition and a large fan working condition. The small fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the inlet section outer wall (2). At this time, a part of the air flows in from the induced ultra-wide flow adjustment range low noise wind tunnel power section air inlet (1), flows through the space surrounded by the front wall surface of the inlet section outer wall (2) and the inner wall surface of the on-off execution pipe section (11) and the outer wall surface of the small fan inlet guide structure (71), enters the small fan rotor blade (72) and the small fan guide vane (73) of the small fan (7) to accelerate, and then flows out from the outer side of the wall surface of the large fan inlet guide structure (81), and successively enters the stationary large fan rotor blade (82) area and the large fan guide vane (83) area. , the area surrounded by the inner wall surface of the outer wall of the inner duct outlet section (5) and the outer wall surface of the large fan outlet guide structure (85), the area surrounded by the inner wall surface of the outer duct to inner duct conveying channel (15) and the inner wall surface of the inner duct to outer duct conveying channel (16), and then flows out from the ejection type inner duct outlet (6), and the other part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall surface of the outer duct (13) and the outer wall surface of the outer duct to inner duct conveying channel (15) and the outer wall surface of the inner duct to outer duct conveying channel (16), and then enters the area surrounded by the rear inner wall surface of the outer duct (13) together with the air flowing out from the ejection type inner duct outlet (6), and the two air flows are mixed to form one air flow, which flows out from the outer duct outlet (14) to the ejection type ultra-wide flow adjustment range low noise wind tunnel power section;The large fan working condition refers to the on-off execution pipe section (11) moving along the annular gap between the actuator outer slideway (10) and the small fan guide vane fixing ring (74) to the wall surface of the large fan inlet guide structure (81). At this time, a part of the air flows in from the inlet (1) of the induced ultra-wide flow adjustment range low noise wind tunnel power section, flows through the inner side of the inlet section outer wall (2), the inner side of the large fan inlet outer wall (3), and the outer side of the small fan inlet guide structure (71), the outer side of the actuator outer slideway (10), and the outer side of the on-off execution pipe section (11), and enters the large fan blade (82) area and the large fan guide vane (83) area in turn, and accelerates to enter the inner wall surface of the inner channel outlet section outer wall (5) and the large fan outlet guide structure (8 5), the area surrounded by the outer wall surface of the outer duct to inner duct conveying channel (15) and the area surrounded by the inner wall surface of the inner duct to outer duct conveying channel (16), and then flows out from the ejection type inner duct outlet (6), and the other part of the air flows from the outer duct inlet (12) into the area surrounded by the front inner wall surface of the outer duct (13), the outer wall surface of the outer duct to inner duct conveying channel (15), and the outer wall surface of the inner duct to outer duct conveying channel (16), and then enters the area surrounded by the rear inner wall surface of the outer duct (13) together with the air flowing out from the ejection type inner duct outlet (6), and the two air flows are mixed to form one air flow, and then flows out from the ejection type ultra-wide flow adjustment range low noise wind tunnel power section from the outer duct outlet (14). ;

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