A total pressure probe with reduced angle of insensitivity limitation

Abstract

The present application relates to the technical field of total pressure measurement of flow field, in particular to a total pressure probe capable of reducing insensitive angle limitation, comprising a rod body, a sensing part and a stagnation cover; the stagnation cover has an expanded opening; an outer wall of the stagnation cover close to the opening is formed with a boundary layer control surface, which is configured as a concave curved surface to guide the incoming flow contacting the boundary layer control surface to flow away from the sensing part; an inner wall of the stagnation cover is formed with a fluid guiding section, a straight pipe section and a pressure relief section; the fluid guiding section is configured as a curved surface converging towards the sensing part; the pressure relief section is configured as an expanded curved surface to guide the incoming flow entering the opening to flow along the wall surface of the fluid guiding section and turn, and the incoming flow is uniformly dispersed in the straight pipe section, and part of the incoming flow flows out of the stagnation cover through the pressure relief section to reduce the pressure; the port of the sensing part is arranged in the straight pipe section. The total pressure probe can increase the measurement angle of the incoming flow direction of the air flow, and can measure the total pressure of the air flow under better working conditions, and the measurement accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of total pressure measurement technology for flow fields such as wind tunnels, aero engines, gas turbines, and outdoor air, specifically a total pressure probe that reduces the limitation of insensitive angles. Background Technology

[0002] In airflow field measurement, the total pressure probe is one of the important tools for detecting the total pressure of the flow field and calculating the flow velocity. Due to its good performance, stable operation, simple structure, and mature technology, it has been widely used.

[0003] Generally, the total pressure recovery coefficient obtained by a total pressure probe should not be less than 99%. Therefore, the total pressure probe needs to be used facing the wind, and the angle between the sensing part and the incoming flow should not be too large. If only the sensing part is used to measure total pressure, the insensitive angle of the total pressure probe is approximately ±10°; by adding a stagnation shield, its insensitive angle can be increased to approximately ±20°. When the incoming flow angle exceeds the above-mentioned limit of the insensitive angle of the total pressure probe, its total pressure recovery coefficient will be less than 99%, and the measurement will fail. Therefore, when using a total pressure probe, the direction of the incoming flow must not exceed its insensitive angle. This limitation on angle and operation during measurement greatly restricts the practical application of the total pressure probe. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a total pressure probe that reduces the limitation of insensitive angle, which can increase the measurement angle of the total pressure probe relative to the airflow direction, that is, it can measure the total pressure of the airflow at a larger angle; in addition, it can measure the total pressure of the airflow at a more favorable airflow condition, and the measurement accuracy is improved.

[0005] To achieve the above objectives, the present invention provides a total pressure probe that reduces the limitation of insensitive angles. The probe includes a sensing portion and a stagnation shield coaxially disposed outside the sensing portion. The stagnation shield has an opening that expands away from the sensing portion. A boundary layer control surface is formed on the outer wall of the stagnation shield near the opening. This boundary layer control surface is configured as a concave curved surface in the direction of the stagnation shield axis to guide the incoming flow contacting the boundary layer control surface away from the sensing portion. The inner wall of the stagnation shield sequentially forms a fluid guiding section, a straight pipe section, and a pressure relief section from the opening away from the opening. The fluid guiding section is configured as a constricting curved surface near the sensing portion, and the pressure relief section is configured as a curved surface that expands away from the sensing portion to guide the incoming flow entering the opening along the wall of the fluid guiding section and turning, uniformly dispersing in the straight pipe section. Part of the incoming flow flows out of the stagnation shield after passing through the pressure relief section to reduce pressure. The port of the sensing portion is located in the straight pipe section.

[0006] Furthermore, the angle between the tangent of the boundary layer control surface near the opening and the axis of the stagnation cover is 60°; the diameter of the boundary layer control surface smoothly decreases from the maximum outer diameter value to the minimum outer diameter value from the edge near the opening, and then smoothly expands back to the maximum outer diameter value.

[0007] Furthermore, the angle between the tangent of the fluid guide section near the opening and the axis of the stagnation shield is 60°; the diameter of the fluid guide section smoothly decreases from the maximum inner diameter value to the minimum inner diameter value from the edge near the opening.

[0008] Furthermore, the maximum inner diameter value is equal to the maximum outer diameter value.

[0009] Furthermore, the inner diameter of the straight pipe section is equal to the minimum inner diameter value.

[0010] Furthermore, the wall profile of the boundary layer control surface is a first circular arc; the wall profile of the fluid guiding section is a second circular arc.

[0011] Furthermore, the angle between the tangent of the wall surface of the pressure relief section near the opening and the axis of the stagnation cover is 60°, and the angle between the tangent of the wall surface of the pressure relief section away from the opening and the axis of the stagnation cover is 0°.

[0012] The diameter of the pressure relief section smoothly increases from the minimum inner diameter value to the second largest inner diameter value from the position near the opening.

[0013] Furthermore, the distance between the port of the sensing part and the opening of the stagnation cover is 3mm-5mm.

[0014] Furthermore, the inner wall of the sensing part near the port is chamfered.

[0015] Furthermore, the total pressure probe for reducing insensitivity angle limitation includes a rod body, the sensing part and the stagnation cover are both disposed on the rod body, a fluid channel is opened inside the rod body, one end of the fluid channel is connected to the sensing part, and the other end of the fluid channel is connected to a pressure connector through a pressure tapping tube.

[0016] The beneficial effects of this invention are as follows: A stagnation hood is provided, with a boundary layer control surface on the outer side and a fluid guiding section, a straight pipe section, and a pressure relief section on the inner side. These features complement and reinforce each other, improving the guidance and control of airflow and significantly increasing the insensitive angle. Furthermore, by placing the port of the sensing element in the straight pipe section and optimizing the distance between the port of the sensing element and the leading edge of the stagnation hood, the total airflow pressure can be measured at a more favorable airflow condition, thus improving measurement accuracy. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of a total pressure probe that reduces insensitivity angle limitation in one embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of a total pressure probe with another angle that reduces the limitation of insensitive angles, according to one embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the dimensions of a total pressure probe that reduces insensitivity angle limitation in one embodiment of the present invention;

[0020] Figure 4 This is a cross-sectional view of a total pressure probe that reduces insensitivity angle limitation in one embodiment of the present invention;

[0021] Figure 5 This is an enlarged cross-sectional view of the stagnation cover in one embodiment of the present invention. Figure 3 (AA view);

[0022] Figure 6 This is a schematic diagram of the first and second arcs of the stagnation cover in one embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram showing the dimensions of the stagnation cover and the sensing part in one embodiment of the present invention;

[0024] Figure 8 This is a schematic diagram of the opening in the pressure relief section according to one embodiment of the present invention;

[0025] Figure 9 This is an isometric view of a model used for CFD simulation in one embodiment of the present invention;

[0026] Figure 10 This is a front view of the model used for CFD simulation in one embodiment of the present invention;

[0027] Figure 11 This is a top view of the model used for CFD simulation in one embodiment of the present invention. Figure 10 (Top view)

[0028] Figure 12 This is a top view of the model used for CFD simulation in one embodiment of the present invention. Figure 10 (AA view);

[0029] Figure 13 This is a pressure cloud diagram at 0°C and 0.5 Ma, according to an embodiment of the present invention.

[0030] Figure 14 This is a pressure cloud diagram at 0.5 Ma and 20°, according to an embodiment of the present invention.

[0031] Figure 15 This is a pressure cloud diagram at 0.5 Ma and 40°, according to an embodiment of the present invention.

[0032] Figure 16 This is a pressure cloud diagram at 0.5 Ma and 50°, according to an embodiment of the present invention.

[0033] Figure 17 This is a pressure cloud diagram at 0.5 Ma and 60°, according to an embodiment of the present invention.

[0034] Figure 18 This is a velocity vector diagram at 0° and 0.5 Ma, according to an embodiment of the present invention.

[0035] Figure 19 This is a velocity vector diagram at 0.5 Ma and 20°, according to an embodiment of the present invention.

[0036] Figure 20 This is a velocity vector diagram at 0.5 Ma and 40°, according to an embodiment of the present invention.

[0037] Figure 21 This is a velocity vector diagram at 0.5 Ma and 50°, according to an embodiment of the present invention.

[0038] Figure 22 This is a velocity vector diagram at 0.5 Ma and 60°, according to an embodiment of the present invention.

[0039] Figure 23 This is a curve of "α angle versus total pressure coefficient at 0.1 Ma" measured in a wind tunnel according to an embodiment of the present invention.

[0040] Figure 24 This is a curve of "β angle versus total pressure coefficient at 0.1 Ma" measured in a wind tunnel according to an embodiment of the present invention.

[0041] Figure 25 This is a curve of "α angle versus total pressure coefficient at 0.5 Ma" measured in a wind tunnel according to an embodiment of the present invention.

[0042] Figure 26 This is a curve of β angle versus total pressure coefficient measured in a wind tunnel at 0.5 Ma, according to an embodiment of the present invention.

[0043] In the picture:

[0044] 100. Stagnation hood; 110. Opening; 120. Boundary layer control surface; 130. Fluid guiding section; 140. Straight pipe section; 150. Pressure relief section; 151. Orifice.

[0045] 200. Sensing part; 210. Port; 211. Chamfer.

[0046] 300. Rod body; 310. Rod head assembly; 311. Fluid channel; 320. Support rod.

[0047] 400, Pressure tapping tube,

[0048] 500. Pressure fitting. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] like Figures 1-4 As shown, a total pressure probe with reduced insensitivity angle limitation includes a rod body 300, a sensing part 200, and a stagnation shield 100. The sensing part 200 is disposed on the rod body 300, which has a tubular structure with a fluid channel 311 inside. One end of the fluid channel 311 communicates with the sensing part 200, and the other end of the fluid channel 311 is connected to a pressure connector 500 via a pressure tapping tube 400. The stagnation shield 100 is disposed on the rod body 300 and coaxially disposed outside the sensing part 200. Airflow is guided by the stagnation shield 100 into the sensing part 200 and then enters the pressure tapping tube 400 through the fluid channel 311. See also... Figure 4 In this embodiment, the stagnation cover 100 is vertically fixed to the rod 300. The connection between the stagnation cover 100 and the rod 300 includes, but is not limited to, welding, or injection molding. It is used to increase the insensitive angle, that is, to increase the limit of the measurable airflow angle.

[0051] like Figures 1-4 As shown, the rod body 300 has a tubular structure, including a rod head component 310 and a support rod 320 fixed to one end of the rod head component 310. The rod head component 310 has a fluid channel 311. As an example, in this embodiment, the pressure tapping tube 400 is a pipe with a diameter of φ1.2mm, which passes through the internal tubular cavity of the support rod 320, with its top end connected to the sensing part 200 and its tail end connected to the pressure connector 500. The support rod 320 provides a certain degree of protection for the pressure tapping tube 400 inside it. The pressure connector 500, as the tail end of a total pressure probe that reduces the limitation of insensitive angle, is connected to external pressure acquisition equipment such as a pressure scanning valve. The measured flow field airflow is input through the sensing part 200, passes through the pressure tapping tube 400, and is output through the pressure connector 500. It should be noted that the arrangement of the rod body 300 in this invention includes, but is not limited to, the arrangement of this embodiment.

[0052] Specifically, in conjunction with see Figure 5 and Figure 7The stagnation shield 100 has an opening 110 that expands away from the sensing part 200; a boundary layer control surface 120 is formed on the outer wall of the stagnation shield 100 near the opening 110, and the boundary layer control surface 120 is configured as a curved surface recessed in the axial direction of the stagnation shield 100, such as... Figure 5 As shown, the boundary layer control surface 120 is a funnel-shaped structure that gradually expands away from the rod 300 to guide the incoming flow from the boundary layer control surface to flow away from the sensing part 200. The inner wall of the stagnation shroud 100 is formed sequentially with a fluid guiding section 130, a straight pipe section 140, and a pressure relief section 150 from the opening 110 away from the opening 110. The fluid guiding section 130 is configured as a curved surface that contracts towards the sensing part 200, and the pressure relief section 150 is configured as a curved surface that expands away from the sensing part 200 to guide the incoming flow entering the opening 110 to flow along the wall of the fluid guiding section 130 and turn, and to be evenly dispersed in the straight pipe section 140. Part of the incoming flow flows out of the stagnation shroud 100 after passing through the pressure relief section 150 to reduce pressure. The port 210 of the sensing part 200 is located in the straight pipe section 140.

[0053] The aforementioned total pressure probe with reduced insensitivity angle limitation has a stagnation shield 100 provided on the outside of the sensing part 200. The stagnation shield 100 has an opening 110 that expands away from the sensing part 200. On this basis, a boundary layer control surface 120 is arranged on the outside of the stagnation shield 100, and a fluid guiding section 130, a straight pipe section 140, and a pressure relief section 150 are arranged on the inside. These features cooperate and enhance each other, improve the guidance and control of airflow, and significantly increase the insensitivity angle. The insensitivity angle of the total pressure probe of the present invention can be increased to more than ±60°, thereby reducing the limitations of the use of the total pressure probe.

[0054] During measurement, the airflow comes into contact with the stagnation shield 100 and splits into two parts. One part leaves along the outside of the stagnation shield 100, while the other part enters the interior of the stagnation shield 100. The airflow leaving along the outside of the stagnation shield 100, when flowing at a large angle, impacts the exterior of the stagnation shield 100. Due to the impact and friction of the boundary layer control surface 120 wall, the airflow velocity gradually decreases under the guidance of the boundary layer control surface 120, and the airflow pressure gradually increases. Because of the guidance of the outer profile of the boundary layer control surface 120, the aforementioned part of the airflow is moved away from the inlet of the stagnation shield 100, reducing the intensity of the deceleration and lowering its adverse pressure gradient. This guided airflow will not flow in the opposite direction into the interior of the stagnation shield 100 due to the adverse pressure gradient. Therefore, the part of the airflow entering the interior of the stagnation shield 100 will not be blown away from the wall, nor will the total pressure of the airflow inside the stagnation shield 100 be reduced. In other words, on the one hand, the boundary layer control surface 120 can guide the large-angle airflow to a position away from the stagnation hood opening 110, reducing the reverse pressure of the external airflow. On the other hand, the part of the airflow that enters the stagnation hood 100 can enter the fluid guide section 130 closely along the wall because there is no airflow coming in from the outside. The fluid guiding section 130, the straight pipe section 140, and the pressure relief section 150 work together to guide the incoming flow into the opening 110 along the wall of the fluid guiding section 130 and turn, gradually moving along the axis of the stagnation shroud 100. The flow is evenly dispersed in the straight pipe section 140, eliminating a large amount of airflow unevenness caused by the turn, thereby improving the accuracy of the measurement. Part of the incoming flow flows out of the stagnation shroud 100 after passing through the pressure relief section 150 to reduce pressure, forming a region with better airflow conditions in the straight pipe section 140. Based on this, the port 210 of the sensing part 200 is set in the straight pipe section 140. The optimization of the distance between the port 210 of the sensing part 200 and the leading edge of the stagnation shroud 100 ultimately allows for the measurement of the total airflow pressure at a better airflow condition, thus improving the measurement accuracy.

[0055] Through wind tunnel testing, the total pressure probe of this invention, which reduces the limitation of insensitivity angle, achieves an α angle of -61.4° to 62.5° and a β angle of -61.6° to 64.5° at a flow rate of 0.1 Ma; and an α angle of -62.1° to 63.7° and a β angle of -62.1° to 65.2° at a flow rate of 0.5 Ma. These values ​​exceed the insensitivity angle of conventional total pressure probes (approximately ±20°) by about three times. This invention, on the one hand, allows for a larger measurement angle of the total pressure probe relative to the incoming airflow direction, enabling the measurement of total pressure over a larger angle; on the other hand, it also enables the measurement of total pressure in flow fields with unclear incoming flow conditions and can replace conventional five-hole and seven-hole probes, reducing engineering costs.

[0056] See also Figure 5 and Figure 7In one embodiment, the tangent of the boundary layer control surface 120 near the opening 110 forms a 60° angle with the axis of the stagnation shield 100; the diameter of the boundary layer control surface 120 smoothly decreases from its maximum outer diameter value to its minimum outer diameter value near the edge of the opening 110, and then smoothly expands back to its maximum outer diameter value; the wall profile of the boundary layer control surface 120 is a first circular arc. As an example, in this embodiment, the maximum outer diameter value is φ6mm, the minimum outer diameter value is φ4mm, the leading edge of the boundary layer control surface 120 in contact with the airflow forms a 60° angle with the center, and the structural wall is thin. As the airflow moves backward, its diameter smoothly decreases from φ6mm to φ4mm, then expands again, and the diameter returns to φ6mm at a distance of 5.67mm from the leading edge. The aforementioned total pressure probe for reducing insensitive angle limitation is provided with a boundary layer control surface 120, which can guide the large-angle airflow to a position away from the stagnation shroud opening 110, reduce the reverse pressure of the external airflow, and prevent the external low total pressure airflow from entering the stagnation shroud 100 and blowing up the boundary layer, causing the fluid guide section 130 to malfunction.

[0057] See also Figure 5 and Figure 7 The angle between the tangent of the edge of the fluid guide section 130 near the opening 110 and the axis of the stagnation shroud 100 is 60°. The diameter of the fluid guide section 130 smoothly decreases from its maximum inner diameter to its minimum inner diameter near the edge of the opening 110. The wall profile of the fluid guide section 130 is a second circular arc. As an example, in this embodiment, the fluid guide section 130 is also a flared structure that gradually expands away from the rod 300, with the maximum inner diameter equal to the maximum outer diameter, the maximum inner diameter being φ6mm, and the minimum inner diameter being φ3mm. The tangent of the leading edge of the fluid guide section 130 that is in contact with the airflow makes an angle of 60° with the center, and its inner diameter smoothly decreases from φ6mm to φ3mm. It is then connected to a cylindrical channel with an inner diameter of φ3mm, namely the straight pipe section 140, whose inner diameter is equal to the minimum inner diameter, i.e., φ3mm. After entering the fluid guide section 130, the airflow flows close to the wall due to the "Coanda effect". The flow direction changes to close to 0° with the wall and then acts on the sensing part 200 to measure the total pressure.

[0058] like Figure 6 As shown, the wall profile of the boundary layer control surface 120 is a first circular arc with a radius of R1; the wall profile of the fluid guiding section 130 is a second circular arc with a radius of R2. (See also...) Figure 7 As an example, in this embodiment, the first arc is an arc with a radius of R1=2mm, with a smooth wall and no openings, and the second arc is an arc with a radius of R2=2.5mm, with a smooth wall and no openings.

[0059] like Figure 5As shown, the angle between the tangent of the wall surface of the pressure relief section 150 near the opening 110 and the axis of the stagnation shield 100 is 60°, and the angle between the tangent of the wall surface of the pressure relief section 150 away from the opening 110 and the axis of the stagnation shield 100 is 0°. The diameter of the pressure relief section 150 smoothly increases from the minimum inner diameter value near the opening 110 to the second largest inner diameter value. As an example, in this embodiment, the second largest inner diameter value is φ5mm. The airflow passes through the straight pipe section 140 and then gradually expands to the outlet of the pressure relief section 150. The inner diameter of the outlet is φ5mm, the wall surface is smooth and has no openings, and the angle between the wall tangent and the axis changes from 60° to 0°.

[0060] See also Figure 2 and Figure 8 As shown, specifically, in one embodiment, the pressure relief section 150 includes two rearward openings 151, and the size of the openings 151 is calculated and adjusted during the design process based on the actual dimensions of the boundary layer control surface 120 of the stagnation shroud 100 and the fluid guide section 130. The function of the pressure relief section 150 is to release a portion of the gas and create an airflow with a suitable velocity within the stagnation shroud 100, so that the airflow adheres closely to the fluid guide section 130 due to the flow, without causing boundary layer separation due to excessive velocity.

[0061] See also Figure 5 and Figure 7 In one embodiment, the distance between the port 210 of the sensing part 200 and the opening 110 of the stagnation shield 100 is 3mm-5mm. Within this region, the airflow completes its deflection and does not enter the low-pressure area caused by the pressure relief section 150, resulting in a better area of ​​airflow uniformity. As an example, in this embodiment, the sensing part 200 is a φ1.2×0.3mm pipe, and the distance from its top tip to the leading edge of the stagnation shield 100 is 4mm, which is the optimal position. The above-mentioned total pressure probe, which reduces the limitation of insensitive angle, optimizes the distance between the port 210 of the sensing part 200 and the leading edge of the stagnation shield 100, ultimately enabling the measurement of total airflow pressure at the optimal airflow condition.

[0062] like Figure 5 As shown, in order to expand the insensitive angle of the sensing part 200, the inner wall of the sensing part 200 near the port 210 is provided with a chamfer 211 of C0.3-45° to receive the regulated airflow and detect its total pressure. The chamfer provided on the inner wall of the port 210 can further expand the insensitive angle of the sensing part 200.

[0063] See Figures 9-12 , Figures 13-17As shown, to explore and verify the feasibility, scientific validity, and rationality of the total pressure probe design for reducing the insensitivity angle limitation in this invention, five incoming flow angles (0°, 20°, 40°, 50°, and 60°) and nine distances (0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, and 8mm) were selected, totaling 45 models. CFD simulations were performed under three operating conditions: incoming flow velocities of 0.1 Ma, 0.3 Ma, and 0.5 Ma. In the specific implementation, the SST k-omega model was used, with compressible air as the medium, velocity inlet and pressure outlet as boundary conditions, and a mesh size of 10.85 million.

[0064] Specifically, taking the simulation results under the 0.5 Ma condition as an example, the data regarding the relationship between the pressure recovery coefficient and the angle are as follows: the total inlet pressure is 861 Pa. Calculations show that when the distance between the sensing part 200 and the front end of the stagnation shield 100 is 4 mm, the pressure cloud diagrams at five angles (0°, 20°, 40°, 50°, and 60°) are as follows: Figures 13-17 The pressures measured by the sensing element 200 were 858.658 Pa, 858.932 Pa, 860.911 Pa, 860.501 Pa, and 859.367 Pa, respectively, with total pressure recovery coefficients of 99.73%, 99.76%, 99.99%, 99.94%, and 99.81%. These data show that within the range of α from 0 to 60°, the pressure recovery coefficients are all above 99%, meaning they all meet the requirements for total pressure measurement.

[0065] Specifically, taking the simulation results at a 60° angle as an example, the data regarding the relationship between the pressure recovery coefficient and the position of the sensing part 200 are as follows: when the distance between the sensing part 200 and the front end of the stagnation cover 100 is 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, and 8mm, the pressures it senses are 599.485Pa, 723.527Pa, 845.72Pa, 855.845Pa, 859.367Pa, 858.485Pa, 842.873Pa, 794.574Pa, and 750.742Pa, respectively. The optimal position is between 3mm and 5mm, and the optimal distance is 4mm. From the above data, it can be seen that when α=60°, the pressure recovery coefficient is highest at 4mm when the sensing part 200 is within the 0-8mm range.

[0066] See Figures 18-22 As shown, this is a velocity vector diagram of the total pressure probe with reduced insensitivity angle limitation at an α angle of 0°, 20°, 40°, 50°, and 60° under a flow rate of 0.5 Ma. The direction of airflow and the working effect of each surface can be observed through the airflow direction displayed in the vector diagram.

[0067] Specifically, as can be observed from the vector diagram, the airflow changes direction along the fluid guide section 130 as the probe angle deflects. Between 0° and 20°, the airflow adheres closely to the inner wall of the fluid guide section 130 without backflow or boundary layer separation. Between 20° and 50°, the airflow adheres closely to the inner wall of the fluid guide section 130, generating slight backflow, but without boundary layer separation. At 60°, stronger backflow occurs, and boundary layer separation occurs, but the overall airflow still completes the change of direction, with the airflow acting on the sensing part 200 at a very small angle to the axis. Within the aforementioned 0° to 60° range, the main airflow to the sensing part 200 is not obstructed, does not collide with the surface, and is not mixed with backflow airflow. After being changed, the airflow within the stagnation hood 100 acts directly on the sensing part 200 at an angle close to 0°, making the pressure detectable by the sensing part 200 the airflow with the highest total pressure, thus achieving a high turning capability and a high total pressure recovery coefficient.

[0068] Specifically, see Figure 18 , Figure 19 As shown in the vector diagram, the airflow passing through the boundary layer control surface 120, within the range of 0° to 20°, will generate turbulence at the rear edge of the inlet due to the funnel-shaped design. This turbulence will not affect the airflow inside the stagnation shroud 100, and there will be no backflow into the stagnation shroud 100; according to Figure 20 , Figure 21 , Figure 22 As shown in the vector diagram, at 40°~60°, because the tangential angle of the horn mouth edge is 60°, after deflection, the angle between it and the airflow will become smaller, the airflow will reduce the impact with the wall and change to flow along the wall, reducing the intensity of the reverse pressure gradient, thereby eliminating the problem of the reverse pressure pushing the air into the stagnation hood 100.

[0069] Also see Figures 18-22 The airflow velocity shown indicates that the airflow velocity within the stagnation shroud 100 is relatively consistent within an angle of 0° to 60° between the axis of the stagnation shroud 100 and the airflow. For example, the airflow velocity is 2 to 3 m / s between the inlet edge and the inlet of the sensing section 200. This consistent velocity indicates that the pressure relief section 150 has achieved the purpose of controlling the airflow inside the stagnation shroud 100, creating favorable working conditions for the boundary layer control surface 120 and the fluid guiding section 130.

[0070] See Figures 23-26 As shown, to further verify the feasibility, scientific validity, and rationality of the total pressure probe design for reducing insensitivity angle limitations in this invention, a wind tunnel test was conducted on one embodiment. Specifically, a gimbal was used to rotate the probe, causing changes in the incoming flow angles α and β, and tests were performed at incoming flow velocities of 0.1 Ma and 0.5 Ma, respectively. The relationship between the total pressure recovery coefficient and the angle was obtained as follows:

[0071] At 0.1 Ma, the relationship between the probe axis and the airflow angle at angle α was measured as follows: Figure 23 The α angle, with a total pressure recovery coefficient exceeding 99%, ranges from -61.4° to 62.5°; the relationship between the probe axis and the airflow angle at the β angle is shown in the figure. Figure 24 Its total pressure recovery coefficient is over 99%, and the β angle can reach -61.6° to 64.5°.

[0072] At 0.5 Ma, the relationship between the probe axis and the airflow angle at angle α was measured as follows: Figure 25 The α angle, with a total pressure recovery coefficient exceeding 99%, ranges from -62.1° to 63.7°; the relationship between the probe axis and the airflow angle at the β angle is shown in the figure. Figure 26 Its total pressure recovery coefficient is above 99%, and the β angle is -62.1°~65.2°.

[0073] It should be noted that, Figures 23-26 The horizontal red line represents the coordinate line where the total pressure recovery coefficient equals 0.99; the vertical line represents the angle of the curve when the total pressure recovery coefficient equals 0.99. Additionally, Figures 23-26 The horizontal axis is in degrees.

[0074] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In this invention, unless otherwise explicitly specified and limited, "above" or "below" a second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of a second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

Claims

1. A total pressure probe that reduces insensitivity angle limitations, characterized in that: Includes a sensing part and a stagnation cover coaxially disposed on the outside of the sensing part; The stagnation shield has an opening that expands away from the sensing part; A boundary layer control surface is formed on the outer wall of the stagnation hood near the opening. The boundary layer control surface is configured as a curved surface that is concave in the direction of the stagnation hood axis to guide the incoming flow that contacts the boundary layer control surface to flow away from the sensing part. The inner wall of the stagnation hood is formed sequentially from the opening away from the opening by a fluid guiding section, a straight pipe section, and a pressure relief section. The fluid guiding section is configured as a curved surface that contracts towards the sensing part, and the pressure relief section is configured as a curved surface that expands away from the sensing part, so as to guide the incoming flow entering the opening to flow along the wall of the fluid guiding section and turn, and to be evenly dispersed in the straight pipe section. Part of the incoming flow flows out of the stagnation hood after passing through the pressure relief section to reduce pressure. The port of the sensing part is located in the straight pipe section; The total pressure probe for reducing insensitivity angle limitation includes a rod body, the sensing part and the stagnation cover are both disposed on the rod body, a fluid channel is opened inside the rod body, one end of the fluid channel is connected to the sensing part, and the other end of the fluid channel is connected to a pressure connector through a pressure tapping tube.

2. The total pressure probe for reducing insensitivity angle limitation according to claim 1, characterized in that: The angle between the tangent of the boundary layer control surface near the opening and the axis of the stagnation shield is 60°. The diameter of the boundary layer control surface smoothly decreases from the edge near the opening from the maximum outer diameter value to the minimum outer diameter value, and then smoothly expands back to the maximum outer diameter value.

3. A total pressure probe for reducing insensitivity angle limitation according to claim 2, characterized in that: The angle between the tangent of the fluid guide section near the opening and the axis of the stagnation shield is 60°. The diameter of the fluid guide section smoothly decreases from the maximum inner diameter value to the minimum inner diameter value near the edge of the opening.

4. A total pressure probe for reducing insensitivity angle limitation according to claim 3, characterized in that: The maximum inner diameter value is equal to the maximum outer diameter value.

5. A total pressure probe for reducing insensitivity angle limitation according to claim 3, characterized in that: The inner diameter of the straight pipe section is equal to the minimum inner diameter value.

6. A total pressure probe for reducing insensitivity angle limitation according to claim 3, characterized in that: The wall profile of the boundary layer control surface is a first circular arc; the wall profile of the fluid guiding section is a second circular arc.

7. A total pressure probe for reducing insensitivity angle limitation according to any one of claims 1-6, characterized in that: The angle between the tangent of the wall surface of the pressure relief section near the opening and the axis of the stagnation cover is 60°, and the angle between the tangent of the wall surface of the pressure relief section away from the opening and the axis of the stagnation cover is 0°. The diameter of the pressure relief section smoothly increases from the minimum inner diameter value to the second largest inner diameter value from the position near the opening.

8. A total pressure probe for reducing insensitivity angle limitation according to any one of claims 1-6, characterized in that: The distance between the port of the sensing part and the opening of the stagnation cover is 3mm-5mm.

9. A total pressure probe for reducing insensitivity angle limitation according to any one of claims 1-6, characterized in that: The inner wall of the sensing part near the port is chamfered.

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