Micro-nano magnetic control nozzle module for wind tunnel rectification and preparation method of micro-nano magnetic control nozzle module

Abstract

The invention relates to the field of magnetic control nozzles, in particular to a micro-nano magnetic control nozzle module for wind tunnel rectification and a preparation method of the micro-nano magnetic control nozzle module. The method comprises the following steps: mixing methacrylic acid-2-hydroxyethyl ester, an Irgacure819 photoinitiator, Fe3O4 particles and NdFeB particles, so as to obtain HEMA magnetic hydrogel photosensitive resin; and carrying out 3D printing by using HEMA magnetic hydrogel photosensitive resin to obtain the micro-nano flexible nozzle. The micro-nano magnetic control nozzle modules are arranged in an array mode; all the micro gas channels on all the fixed substrates in one array area are communicated with a gas source; the electromagnet array adopts PID closed-loop control, the current of each electromagnet is adjusted in real time, and a dynamic magnetic field is generated. The micro-nano flexible nozzle can be in three working states of a constant flow mode, a pulse mode and a direction random switching mode, and diversified flow field environments can be simulated.

Description

Technical Field

[0001] The present invention relates to the field of magnetically controlled nozzles, and more specifically to a micro-nano magnetically controlled nozzle module for wind tunnel rectification and a preparation method thereof. Background Art

[0002] Ground effect refers to the phenomenon that when an aircraft approaches the ground or water surface, the aerodynamic characteristics change significantly due to the boundary limitation of the flow field. Wind tunnel tests are the main means for ground effect research, which can simulate the flow field environment and provide data support to ensure the technical guarantee for high-precision aerodynamic analysis. Based on the ground effect research, the aerodynamic characteristic data of the aircraft during takeoff, landing and near-ground flight phases can be obtained, and then the aerodynamic shape design of the aircraft can be optimized. However, in the current wind tunnel tests, usually only the ground effect simulation of a single flow field can be carried out, and it is impossible to simulate the influence of the ground effect on the aircraft when the aircraft faces complex turbulent flows such as crosswinds, gusts, wind shear and turbulence during actual flight. Therefore, a wind tunnel rectification device is needed to truly simulate the flow field characteristics under complex turbulent flow scenarios. Summary of the Invention

[0003] The present invention provides a micro-nano magnetically controlled nozzle module for wind tunnel rectification and a preparation method thereof, aiming to provide a diversified flow field environment.

[0004] The above object is achieved by the following technical solutions:

[0005] A micro-nano magnetically controlled nozzle module includes a fixed base, a micro gas channel is arranged on the fixed base, a micro-nano flexible nozzle communicated with the micro gas channel is fixedly connected to the fixed base, and an electromagnet is fixedly connected to the outer side wall of the fixed base.

[0006] The diameter of the micro gas channel and / or the caliber of the micro-nano flexible nozzle is not greater than 100 μm.

[0007] The micro-nano flexible nozzle is fixedly connected to the fixed base using epoxy resin glue and / or the electromagnet is fixedly connected to the fixed base using epoxy resin glue.

[0008] An electromagnet is fixedly connected to each of the four sides of the wall of the fixed base.

[0009] The fixed base is connected to a gas source, so that the micro-nano flexible nozzle can generate an air flow, thereby realizing blowing or suction.

[0010] A preparation method of a micro-nano flexible nozzle includes the following steps:

[0011] Step 1: Mix 78.4 wt.% 2-hydroxyethyl methacrylate, 1.6 wt.% Irgacure 819 photoinitiator, 10 wt.% Fe3O4 particles and 10 wt.% NdFeB particles to obtain HEMA magnetic hydrogel photosensitive resin;

[0012] Step 2: Use HEMA magnetic hydrogel photosensitive resin for 3D printing to obtain a micro-nano flexible nozzle.

[0013] The ratio of Fe3O4 particles to NdFeB particles is 1:1.

[0014] During the mixing, ultrasonic treatment is carried out for 1 h, and then magnetic stirring is carried out for 1 h.

[0015] A preparation method of a micro-nano magnetically controlled nozzle module for wind tunnel rectification includes the following steps:

[0016] Step 1: Arrange the micro-nano magnetically controlled nozzle modules in an array.

[0017] Step 2: All the micro gas channels on all the fixed substrates in an array area are connected to a gas source.

[0018] Step 3: The electromagnet array adopts PID closed-loop control to adjust the current of each electromagnet in real time and generate a dynamic magnetic field.

[0019] The beneficial effects of the micro-nano magnetically controlled nozzle module for wind tunnel rectification and its preparation method of the present invention are as follows:

[0020] The micro-nano flexible nozzle is prepared by 3D printing, which solves the process limitation problems that it is difficult to prepare high-precision three-dimensional magnetic microstructures by traditional magnetic functional element preparation methods and the multi-material integration problem that it is difficult to integrate magnetic materials and non-magnetic materials in the same device.

[0021] The material of the micro-nano flexible nozzle includes photosensitive resin-based hydrogel doped with Fe3O4 particles and NdFeB particles. The Fe3O4 nanoparticles enhance the light absorption and improve the printing accuracy. The NdFeB particles provide high coercivity and remanence to ensure the strong magnetism of the device, solving the problem that it is difficult to achieve both high printing accuracy and strong magnetism caused by doping only one material in the traditional process. The hydrogel ensures the flexibility of the printed parts.

[0022] The fixed substrate and the micro-nano flexible nozzle are adhered by epoxy resin glue added with a toughening agent, which ensures that the bonding interface is not easy to fall off when the nozzle undergoes flexible deformation and also ensures the airtightness of the connection.

[0023] The electromagnets in the micro-nano magnetically controlled nozzle module are adhered to the four side surfaces of the fixed substrate by epoxy resin glue. This adhesion method has no stress concentration, is easy to operate, and is suitable for precise magnetic field control. The currents on the four electromagnets are controlled separately to generate multiple magnetic fields with different intensities and directions, and finally realize the coordinated driving of the nozzle deformation by multiple coils.

[0024] The electromagnet array adopts PID closed-loop control to adjust the current of each electromagnet in real time and generate a dynamic magnetic field, which can make the nozzle operate in three working states: constant current mode, pulse mode, and randomly switched direction mode, and can simulate diverse flow field environments. Description of the Drawings

[0025] Figure 1 It is a sectional view of the micro-nano magneto-controlled nozzle module;

[0026] Figure 2 It is a microscopic schematic diagram of NdFeB-Fe3O4 photosensitive resin-based hydrogel;

[0027] Figure 3 It is a schematic diagram of the micro-nano flexible nozzle turning.

[0028] In the figure: fixed base 1, micro gas channel 2, micro-nano flexible nozzle 3, and electromagnet 4. Detailed Implementation Manner

[0029] A micro-nano magneto-controlled nozzle module for wind tunnel rectification includes a fixed base 1, on which longitudinal micro gas channels 2 are evenly distributed. The upper end of the fixed base 1 is bonded with a micro-nano flexible nozzle 3 by epoxy resin glue. The micro-nano flexible nozzle 3 has a conical hollow structure. The number of micro-nano flexible nozzles 3 is the same as the number of micro gas channels 2, and the positions of the micro-nano flexible nozzles 3 correspond one by one to the micro gas channels 2, so that each micro gas channel 2 is communicated with a micro-nano flexible nozzle 3. An electromagnet 4 is fixedly connected to the outer side wall of the fixed base 1 by epoxy resin glue.

[0030] Further, the fixed base 1 is made of non-magnetic aluminum alloy material, with a cuboid shape, and the four longitudinal edges on the side are rounded. The aluminum alloy material will not interfere with the magnetic field generated by the electromagnet 4.

[0031] An air supply hose is fixedly connected to the lower end of the fixed base 1 by epoxy resin glue, so that all the micro gas channels 2 on the fixed base 1 are communicated with the air supply hose. Then, the air supply hose is fixedly connected and communicated with the air supply position of the air pump, so that all the micro-nano flexible nozzles 3 can blow air.

[0032] Among them, further, the preparation method of the micro-nano flexible nozzle 3 is as follows:

[0033] First, 78.4 wt.% 2-hydroxyethyl methacrylate (HEMA), 1.6 wt.% Irgacure 819 photoinitiator, 10 wt.% Fe3O4 particles, and 10 wt.% NdFeB particles are mixed together [[Whether ultraviolet light should be irradiated at this time, or whether there is content of curing by irradiating ultraviolet light]]. Then, ultrasonic treatment is carried out for 1 h to prevent particle agglomeration, and then magnetic stirring is carried out for 1 h to make the magnetic particles evenly distributed, obtaining HEMA magnetic hydrogel photosensitive resin. Finally, a micro-nano flexible nozzle 3 is obtained by 3D printing using this as the material. The micro-nano flexible nozzle 3 prepared by this method can maintain a high elastic modulus, effectively avoid the deformation of micro-scale structures caused by internal structural stress, ensure the manufacturing accuracy, and is not easily damaged during deformation due to its high toughness, effectively ensuring the reliability of the device.

[0034] Among them, when the ratio of Fe3O4 particles to NdFeB particles is 1:1, the Fe3O4 nanoparticles enhance the light absorption and improve the printing accuracy, and the NdFeB particles provide high coercivity and remanence to ensure the strong magnetism of the device.

[0035] The 3D printing adopts the micro-continuous liquid interface production (μCLIP) method. Compared with the extrusion printing (FDM) and direct ink writing (DIW), it can achieve higher printing accuracy and is very suitable for printing the micro-nano flexible nozzle 3 of the present invention. The caliber of the micro-nano flexible nozzle 3 is below 100 μm.

[0036] The use of 3D printing technology enables the direct printing of a high-precision micro-nano flexible nozzle 3 structure, realizes the integration of magnetic materials and non-magnetic materials, greatly improves the preparation efficiency, and the low-viscosity characteristic of the photosensitive resin facilitates the uniform dispersion of magnetic nanoparticles, ensuring the uniformity of the magnetic response of the material and avoiding local magnetic field failure.

[0037] Furthermore, a preparation method of a micro-nano magnetically controlled nozzle module for wind tunnel rectification includes the following steps:

[0038] Step 1: Bond the micro-nano flexible nozzle 3 and the fixed substrate 1 together with epoxy resin glue;

[0039] Step 2: Bond the electromagnets 4 to the four sides of the fixed substrate with an adhesive to form an array of electromagnets 4, completing the installation of the micro-nano magnetically controlled nozzle module.

[0040] Step 3: The micro-nano magnetron nozzle modules for wind tunnel rectification are arrayed for batch use. An air pump is used to supply air to an area formed after the array. All the ventilation hoses in this area are connected and fixed and connected to an air collection structure. This air collection structure can be a 3D printed multi-joint structure or a box structure. The multi-joint structure is then fixed and connected to an air pump. The air pump is used to pump air into the air collection structure and then distribute it to each ventilation hose. If the air delivery structure of the air pump has a multi-joint structure, the ventilation hose can also be directly fixed and connected to the air delivery structure of the air pump.

[0041] The electromagnet array 4 uses PID closed-loop control to adjust the current of each electromagnet 4 in real time to generate a dynamic magnetic field. The air pump is connected to the electromagnetic pressure valve below each micro-nano magnetic control nozzle module through parallel gas pipelines. The electromagnetic pressure valve is then connected to the corresponding micro-nano magnetic control nozzle module through the air pipe. One electromagnetic pressure valve corresponds to one micro-nano magnetic control nozzle module. The micro-nano flexible nozzle 3 can be operated in three modes: constant flow mode, pulse mode, and random direction switching mode, which can simulate a variety of flow field environments.

[0042] The constant flow mode is achieved by applying a constant uniform magnetic field, stabilizing the inner diameter and direction of the nozzle, while the air pump maintains a constant air pressure, the electromagnetic pressure valve remains fully open, and the fluid is output at a stable flow rate.

[0043] The pulse mode is implemented by controlling the 4-array electromagnet to generate an alternating magnetic field to drive the nozzle to contract / expand periodically, while coordinating the pulse air pressure generated by the electromagnetic pressure valve to synchronize the frequency and enhance the fluid injection pulse characteristics.

[0044] The random direction switching mode is implemented by generating a random direction magnetic field through an array of electromagnets 4, such as randomly switching the X / Y directions, inducing the micro-nano flexible nozzle 3 to continuously deform, changing the fluid path, and realizing random changes in the injection direction.

[0045] Preferably, a toughening agent is added to the epoxy resin glue used for the micro-nano flexible nozzle 3 to prevent bonding failure caused by frequent deformation of the micro-nano flexible nozzle 3, and also to avoid bonding failure caused by heating of the electromagnet 4. This fixing method is very suitable for precision instruments, has strong stability, and is easy to implement.

Claims

1. A micro-nano magnetically controlled nozzle module, comprising a fixed substrate (1), a micro gas channel (2) is arranged on the fixed substrate (1), a micro-nano flexible nozzle (3) communicated with the micro gas channel (2) is fixedly connected to the fixed substrate (1), and an electromagnet (4) is fixedly connected to the outer side wall of the fixed substrate (1).

2. The micro-nano magnetically controlled nozzle module according to claim 1, wherein the diameter of the micro gas channel (2) and / or the aperture of the micro-nano flexible nozzle (3) is not greater than 100 μm.

3. The micro-nano magnetically controlled nozzle module according to claim 1, wherein the micro-nano flexible nozzle (3) is fixedly connected to the fixed substrate (1) using epoxy resin glue and / or the electromagnet (4) is fixedly connected to the fixed substrate (1) using epoxy resin glue.

4. The micro-nano magnetically controlled nozzle module according to claim 1, wherein an electromagnet (4) is fixedly connected to each of the four sides of the wall of the fixed substrate (1).

5. The micro-nano magnetically controlled nozzle module according to claim 1, wherein the fixed substrate (1) is connected to a gas source so that the micro-nano flexible nozzle (3) can generate an air flow.

6. A preparation method of a micro-nano flexible nozzle (3), comprising the following steps: Step 1: Mix 70 wt.% - 80 wt.% 2-hydroxyethyl methacrylate (HEMA), 1 wt.% - 2 wt.% photoinitiator, and the rest are Fe3O4 particles and NdFeB particles to obtain HEMA magnetic hydrogel photosensitive resin; Step 2: Use the HEMA magnetic hydrogel photosensitive resin for 3D printing to obtain the micro-nano flexible nozzle (3).

7. The micro-nano magnetically controlled nozzle module according to claim 6, wherein the weight percentage ratio of the Fe3O4 particles to the NdFeB particles is 1:

1.

8. The micro-nano magnetically controlled nozzle module according to claim 7, wherein during the mixing, ultrasonic treatment is performed for 1 h, and then magnetic stirring is performed for 1 h.

9. A preparation method of a micro-nano magnetically controlled nozzle module for wind tunnel rectification, comprising the following steps: Step 1: Arrange the micro-nano magnetically controlled nozzle modules in an array; Step 2: All the micro gas channels (2) on all the fixed substrates (1) in an array area are communicated with a gas source; Step 3: The electromagnet (4) array adopts PID closed-loop control to adjust the current of each electromagnet (4) in real time to generate a dynamic magnetic field.

10. The micro-nano magnetically controlled nozzle module according to claim 9, wherein the micro-nano flexible nozzle (3) and / or the electromagnet (4) are fixed to the corresponding fixed substrate (1) using epoxy resin glue.

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