A three-dimensional isotropic turbulence generating device

Abstract

The application discloses a three-dimensional isotropic turbulent flow generating device, which comprises a second container and a plurality of nozzles, liquid enters the nozzles and is sprayed in a direction of the nozzles, since the speed of liquid sprayed from each nozzle is equal, the chamber has a center point, the distance from each corner to the center point is equal, and the direction of each nozzle is towards the center point, so that isotropic turbulent flow can be formed in the central position of the second container and the surrounding area, in the process, the application reduces the complexity of the device, relies on gravity to drive the liquid flow, through the arrangement of the nozzles and the second container, multiple jet flows can collide in the second container, and three-dimensional isotropic turbulent flow is generated, since the liquid flow source has high consistency, the isotropic degree of the generated turbulent flow is guaranteed, the system complexity is effectively reduced, a technology for generating three-dimensional isotropic turbulent flow with high isotropy is provided, and beneficial effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of fluid mechanics experimental equipment, and more specifically to a three-dimensional isotropic turbulence generation device. Background Technology

[0002] In existing fluid mechanics experiments, the study of isotropic turbulence is a common research topic. It requires personnel to first create fluid turbulence in the laboratory using equipment before they can record, experiment with, and study the turbulence.

[0003] In existing technologies, grid flow and shear flow are mostly used to generate isotropic turbulence. Grid flow turbulence generators require the relative motion between the fluid and the grid to induce isotropic turbulence, thus requiring a fluid loop to drive the fluid motion or a linear motor to drive the grid reciprocating motion, resulting in system complexity and high cost. Shear flow turbulence generators use one or more pairs of counter-rotating impellers to stir the fluid, creating a shear layer inside the fluid. The instability of the shear layer can induce isotropic turbulence. This method requires high-speed motor rotation (over 1000 rpm) to ensure the turbulence intensity of the generated flow, resulting in high energy consumption and placing high demands on the rotational sealing of the container.

[0004] When using the aforementioned common equipment to generate two-dimensional turbulence, its shortcomings are acceptable. However, when studying three-dimensional turbulence, because the mesh and shear layer are both two-dimensional structures in space, and the flow transition and instability also mainly exhibit isotropic characteristics in the two-dimensional plane, the generated isotropic turbulence often only exhibits isotropic characteristics in the two-dimensional plane, which is difficult to meet the generation requirements of three-dimensional isotropic turbulence. If an additional dimension is added under the existing technical approach, the system complexity needs to be significantly increased on the basis of the existing complexity, thereby causing a decrease in equipment reliability and an increase in cost. Summary of the Invention

[0005] This invention provides a gravity-driven jet three-dimensional isotropic turbulence generation device that can balance low system complexity with the generation of high three-dimensional isotropic turbulence, comprising:

[0006] The second container has a regular prism-shaped chamber inside, with multiple corners and a center point. The distance from each corner to the center point is equal. The second container has a second outlet, from which liquid entering the chamber can flow out.

[0007] Multiple nozzles, each corresponding to a corner of the chamber, are positioned at the corresponding corner. Each nozzle is used to spray liquid from an external liquid source into the chamber. All nozzles are oriented towards the center of the chamber, and the liquid exits from the nozzles at the same speed.

[0008] Furthermore, it also includes:

[0009] A first container is configured to hold liquid, a second container has a lower vertical height than the first container, and the first container is connected to each nozzle.

[0010] A third container is configured to contain liquid. The vertical height of the third container is lower than that of the second container. The third container is connected to the internal chamber of the second container and is also connected to the first container.

[0011] A water pump is provided between the third container and the first container. The water pump is used to pump the liquid inside the third container into the first container. Valves are provided between the first container and the second container, between the second container and the third container, and between the third container and the first container.

[0012] Furthermore, the internal chamber of the second container is a regular square prism with eight corners, and also includes eight first connecting pipes, one first connecting pipe corresponding to one nozzle. The first connecting pipe connects the corresponding nozzle to the first container. The central axis of the second container is horizontal, and the second container has two opposing mounting sidewalls on the central axis. Each mounting sidewall has four first connecting pipes that pass through to connect to the nozzle. The four first connecting pipes located on the same mounting sidewall are parallel to each other, so that the pressure loss generated by the liquid flow through each first connecting pipe is consistent.

[0013] Furthermore, it also includes eight second connecting pipes, which connect the second container and the third container. Each mounting sidewall has four second connecting pipes that are connected to the second container, and the four second connecting pipes located on the same mounting sidewall are parallel to each other.

[0014] Furthermore, the first container has a vertical central axis and eight first outlets, each of which is symmetrical about the central axis of the first container, so as to keep the flow rate and direction of the liquid flowing out from each first outlet consistent. The first connecting pipe is connected to the first container through the first outlets.

[0015] Furthermore, the central axis of the second container is horizontal, and each mounting side wall has four second water inlets and four second water outlets. Each second water inlet is connected to a nozzle, and the second water outlets are connected to the interior of the second container. Each second water inlet on each mounting side wall is symmetrical about the central axis of the second container, and each second water outlet on each mounting side wall is symmetrical about the central axis of the second container. The first connecting pipe is connected to the nozzle through the second water inlet, and the second connecting pipe is connected to the second container through the second water inlet.

[0016] Furthermore, the third container has a vertical central axis and eight third inlets, each of which is symmetrical about the central axis of the third container to ensure that the liquid flowing in from each third inlet maintains a consistent flow rate and direction. The second connecting pipe is connected to the second container through the third inlets.

[0017] Furthermore, the nozzle includes a nozzle and a fixing part. The fixing part is located at the corner inside the second container and is detachably connected to the second container. The nozzle passes through the fixing part and faces the center point of the internal cavity of the second container. The fixing part is used to maintain the orientation of the nozzle. A nozzle and its corresponding second water inlet are connected by a pipe buried inside the second container.

[0018] Furthermore, the second container also includes a box body, with a mounting sidewall detachably connected to each end of the box body on the central axis of the second container. A fixing part is fixedly connected to the mounting sidewall, and a sealing layer is provided between the outside of the fixing part and the inner sidewall of the box body. The sealing layer is fixedly connected to the outside of the fixing part.

[0019] Furthermore, the first container has a first inlet, the first container includes a first tank body, the first inlet and the first outlet are both located at the bottom of the first tank body, there is one and only one first inlet, the first inlet is located at the center of the bottom of the first tank body, each first outlet is centrally symmetrical around the first inlet, the lower end of the side wall of the first tank body has a guide cone surface, the guide cone surface is used to guide and collect the liquid towards the middle of the lower wall of the first tank body, the connection between the guide cone surface and the lower wall of the first tank body surrounds the periphery of each first outlet.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: In use, since each nozzle is configured such that the liquid sprays out of the nozzle at the same speed, the distance from each corner to the center point of the chamber is equal, and the orientation direction of each nozzle is towards the center point, based on the prism spatial property of the second container chamber, when the prism chamber is filled with liquid, isotropic turbulence is formed in the central position and surrounding area of ​​the second container, thus achieving the technical effect. In the above process, the present invention reduces the complexity of the device, relies on gravity to drive the liquid flow, and through the setting of the nozzle and the second container, multiple jet collisions can be generated in the second container, thereby generating three-dimensional isotropic turbulence. Moreover, since the liquid flow source has high consistency, the isotropic degree of the generated turbulence is guaranteed. While effectively reducing the system complexity, a technique for generating highly isotropic three-dimensional isotropic turbulence is proposed, achieving beneficial effects. Attached Figure Description

[0021] Figure 1 This is a schematic front view of one embodiment;

[0022] Figure 2 This is a partial front sectional view of one embodiment;

[0023] Figure 3 This is a top view schematic diagram of one embodiment;

[0024] Figure 4 This is a three-dimensional schematic diagram of one embodiment;

[0025] Figure 5 This is a cross-sectional view of the diagonal section of a second container component according to one embodiment;

[0026] Figure 6 This is a schematic diagram of the component connection relationship in one embodiment.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. First container; 11. First inlet; 12. First outlet; 2. Second container; 21. Second inlet; 22. Second outlet; 23. Mounting side wall; 24. Box body; 3. Third container; 31. Third inlet; 32. Third outlet; 4. Nozzle; 41. Nozzle; 42. Fixing part; 51. First valve; 52. Second valve; 53. Third valve; 61. First connecting pipe; 62. Second connecting pipe. Detailed Implementation

[0029] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] The present invention provides a three-dimensional isotropic turbulence generation device, comprising: a second container 2, the second container 2 having a regular prism-shaped chamber with multiple corners and a center point, the distance from each corner to the center point being equal; the second container having a second outlet 22, through which liquid entering the chamber can flow out; and multiple nozzles 4, each nozzle 4 corresponding to a corner of the chamber, the nozzle 4 being disposed at its corresponding corner, each nozzle 4 being used to spray liquid from an external liquid source into the chamber, the orientation of each nozzle 4 being towards the center point of the chamber, and the velocity of the liquid ejected from the nozzle 4 being equal.

[0031] For details, please refer to Figures 1-6In this embodiment, the chamber is a regular square prism with eight corners and eight nozzles 4. During use, since each nozzle 4 is configured such that the liquid ejected from the nozzle 4 has the same velocity, the distance from each corner to the center point of the chamber is equal, and the orientation of each nozzle 4 is towards the center point, based on the regular prism spatial property of the second container 2 chamber, when the regular prism chamber is filled with liquid (at this time the liquid geometry is also a regular prism liquid column), isotropic turbulence is formed in the central position and surrounding area of ​​the second container 2, thus achieving the technical effect.

[0032] In the above process, the present invention reduces the complexity of the device, relies on gravity to drive the liquid flow, and by setting the nozzle 4 and the second container 2, multiple jet collisions can be generated in the second container 2, thereby generating three-dimensional isotropic turbulence. Since the liquid flow source has high consistency, the isotropic degree of the generated turbulence is guaranteed. While effectively reducing the system complexity, a technique for generating highly isotropic three-dimensional isotropic turbulence is proposed, achieving beneficial effects.

[0033] Furthermore, it also includes: a first container 1, configured to contain liquid; a second container 2 with a vertical height lower than that of the first container 1; the first container 1 being connected to each nozzle 4; a third container 3, configured to contain liquid; the third container 3 with a vertical height lower than that of the second container 2; the third container 3 being connected to the internal chamber of the second container 2 and also connected to the first container 1; a water pump, provided between the third container 3 and the first container 1, used to pump the liquid inside the third container 3 into the first container 1; and valves provided between the first container 1 and the second container 2, between the second container 2 and the third container 3, and between the third container 3 and the first container 1.

[0034] Specifically, the first container 1 contains a predetermined amount of liquid, and all valves are kept closed. Using conventional technical means such as external equipment or brackets, the first container 1 is placed at a predetermined height. The passage between the first container 1 and the second container 2 is opened using valves. The liquid in the first container enters the nozzle 4 and is sprayed out in the direction of the nozzle 4. In this embodiment, the liquid in the first container flows downwards under the driving force of gravity and enters the nozzle 4. At the same time, the passage between the third container 3 and the first container 1 is opened using valves. The liquid inside the second container 2 flows out of the second container 2 and flows upwards back to the first container 1 under the action of a water pump, ensuring the continuous operation of the device and the continuous generation of turbulence.

[0035] In this embodiment, during the process of the liquid flowing back from the second container 2 to the first container 1, the speed at which the liquid flows out of the second container 2 is slower than the speed at which it enters the second container 2 by controlling the water pump. This reduces the system flow resistance and improves efficiency while ensuring the turbulence intensity in the central region.

[0036] Furthermore, considering that the means by which this application achieves high three-dimensional isotropy of turbulence is by using eight nozzles 4, and the liquid source of the nozzles 4 comes from the supply of the first container 1, in order to ensure the stability and consistency of the liquid flow out of the first container 1, and to ensure the high consistency of the liquid flow entering the second container 2 (i.e. the liquid flow supplied to the eight nozzles 4), specifically, eight first connecting pipes 61 are also included. One first connecting pipe 61 corresponds to one nozzle 4. The first connecting pipe 61 is connected between its corresponding nozzle 4 and the first container 1. The central axis of the second container is horizontal. The second container has two opposing mounting sidewalls 23 on the central axis. Four first connecting pipes 61 are inserted into each mounting sidewall 23 to connect with the nozzles 4. The four first connecting pipes 61 located on the same mounting sidewall 23 are parallel to each other, so that the pressure loss generated by the liquid flow through each first connecting pipe 61 is consistent, ensuring the stability and consistency of the liquid flow supplied to the eight nozzles 4, and improving the high isotropy of turbulence.

[0037] Furthermore, considering that the fluid movement of the liquid inside the second container 2 is also affected by the liquid flow out of the second container 2, in order to ensure that the liquid flow out of the second container 2 has high consistency, eight second connecting pipes 62 are also included. The second connecting pipes 62 are connected between the second container 2 and the third container 3. There are four second connecting pipes 62 on each mounting side wall 23 that are connected to the second container 2. The four second connecting pipes 62 located on the same mounting side wall 23 are parallel to each other. This symmetrical arrangement ensures that the liquid flow supplied to the eight nozzles 4 has high consistency, thereby improving the high homogeneity of the turbulence.

[0038] Furthermore, considering that the fluid motion of the liquid flowing out of the first container 1 is affected by the outflow, especially the velocity and direction of the flow are affected by the geometric position of the outflow point in the liquid space, and specifically, the first container 1 has a vertical central axis and eight first outlets 12, each of which is symmetrical about the central axis of the first container 1. The first connecting pipe 61 is connected to the first container through the first outlets 12. In this way, each outflow point is homogeneous in terms of the overall liquid space inside the first container 1, thereby ensuring that the liquid flowing out from each first outlet 12 maintains the consistency of velocity and direction, thus improving the high homogeneity of the turbulence.

[0039] Furthermore, considering that the fluid movement of the liquid flowing into and out of the second container 2 is affected by the outflowing liquid flow, especially the flow velocity and direction are affected by the geometric position of the outflow point in the liquid space, the central axis of the second container 2 is horizontal. Each mounting sidewall 23 has four second inlets 21 and four second outlets 22. One second inlet 21 is connected to one nozzle 4, and the second outlets are connected to the interior of the second container 2. Each second inlet 21 on each mounting sidewall 23 is symmetrical about the central axis of the second container 2, and each second outlet 22 on each mounting sidewall 23 is symmetrical about the central axis of the second container 2. The first connecting pipe 61 is connected to the nozzle 4 through the second inlet 21, and the second connecting pipe 62 is connected to the second container 2 through the second inlet 21. Each outflow point is homogeneous with respect to the overall liquid space inside the first container 1, and each outflow point is also homogeneous with each other, thereby ensuring that the liquid flowing into and out of the second container 2 maintains the same flow velocity and direction, thus improving the high homogeneity of the turbulence.

[0040] Furthermore, although the liquid flow into the third container 3 does not directly participate in generating turbulence inside the second container 2, the liquid flow state inside the first container 1 directly affects the liquid flow entering the second container 2. Therefore, if the liquid flow inside the third container 3 is unstable and is sent into the first container 1 in a state of chaotic flow, it will inevitably affect the generation of turbulence inside the second container 2. Therefore, the third container 3 has a vertical central axis and eight third inlets 31, each symmetrically positioned around the central axis of the third container 3, to ensure that the liquid flowing in from each third inlet 31 maintains a consistent flow velocity and direction. The second connecting pipe 62 is connected to the second container 2 through the third inlets 31. Thus, after these highly consistent liquid flows enter the third container 3, they can ensure that the liquid inside the third container 3 is in a dynamic steady state, which is beneficial for the generation of liquid flow in the second container 2 after being sent into the first container 1.

[0041] Furthermore, considering that the nozzle 4 is the structural component directly relied upon for turbulence generation in this device, it needs to ensure high stability and low complexity. Therefore, the nozzle 4 includes an orifice 41 and a fixing part 42. The fixing part 42 is located at the corner inside the second container 2 and is detachably connected to the second container 2. The orifice 41 passes through the fixing part 42 and faces the center point of the internal cavity of the second container 2. The fixing part 42 is used to maintain the orientation of the orifice 41. One orifice 41 is connected to its corresponding second inlet 21 through a pipe embedded inside the second container 2. The liquid flow power comes solely from the gravity experienced when falling from the first container 1. The nozzle 4 uses the orifice 41 as a guide to achieve turbulence generation, while the fixing part 42 ensures the stability of the orifice 4's orientation.

[0042] Furthermore, due to the importance of nozzle 4 for unidirectional operation, it requires inspection, maintenance, and replacement after multiple experiments. To facilitate these operations, the second container 2 also includes a housing 24. Each end of the housing 24 on the central axis of the second container 2 is detachably connected to a mounting sidewall 23. A fixing part 42 is fixedly connected to the mounting sidewall 23. A sealing layer 231 is provided between the outside of the fixing part 42 and the inner sidewall of the housing 24, and the sealing layer 231 is fixedly connected to the outside of the fixing part 42. This facilitates the inspection, maintenance, and replacement of nozzle 4.

[0043] Furthermore, the first container 1 has a first inlet 11. The first container 1 includes a first tank body. The first inlet 11 and the first outlet 12 are both located at the bottom of the first tank body. There is only one first inlet 11. The first inlet 11 is located at the center of the bottom of the first tank body. Each first outlet 12 is centrally symmetrical around the first inlet 11. The lower end of the side wall of the first tank body has a guide cone surface 7. The guide cone surface 7 is used to guide and collect the liquid towards the middle of the lower wall of the first tank body. The connection between the guide cone surface 7 and the lower wall of the first tank body surrounds the periphery of each first outlet 12.

[0044] Furthermore, the third container 3 has a third outlet 32. The third container 3 includes a second tank body. The third outlet 32 ​​and the third inlet 31 are both located at the bottom of the second tank body. The third outlet 32 ​​is located at the center of the bottom of the second tank body. Each third inlet 31 is centrally symmetrical around the third outlet 32. The lower end of the side wall of the second tank body has a guide cone surface 7. The guide cone surface 7 is used to guide and collect the liquid towards the middle of the lower wall of the second tank body. The connection between the guide cone surface 7 and the lower wall of the second tank body surrounds the periphery of each third inlet 31.

[0045] In one embodiment, to facilitate the implementation of the experiment, the specific positions of each valve are set. Specifically, the valves located between the first container 1 and the second container 2 include multiple first valves 51, and the valves located between the second container 2 and the third container 3 include multiple second valves 52. One first valve 51 corresponds to one second water inlet 21, and one second valve 52 corresponds to one second water outlet 22. The first valve 51 is located between its corresponding second water inlet 21 and the first water outlet 12, and the second valve 52 is located between its corresponding second water outlet 22 and the third water inlet 31.

[0046] In one embodiment, in order to facilitate the control of the experimental process, a control device is also included. The valve between the third container 3 and the first container 1 is a third valve 53. The first valve 51, the second valve 52 and the third valve 53 are solenoid valves. The control device is signal connected to the first valve 51, the second valve 52 and the third valve 53. The control device is used to control the opening and closing of the first valve 51, the second valve 52 and the third valve 53.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional isotropic turbulence generation device, characterized in that, include: The second container (2) has a regular prism-shaped chamber inside, the chamber has multiple corners, the chamber has a center point, and the distance from each corner to the center point is equal. The second container has a second outlet (22), and the liquid entering the chamber can flow out from the second outlet (22). Multiple nozzles (4), one nozzle (4) corresponds to one corner of the chamber, the nozzle (4) is located at its corresponding corner, each nozzle (4) is used to spray liquid from an external liquid source into the chamber, the orientation of each nozzle (4) is towards the center point of the chamber, and the speed of the liquid sprayed out from the nozzle (4) is equal. Also includes: The first container (1) is configured to contain liquid, the vertical height of the second container (2) is lower than the vertical height of the first container (1), and the first container (1) is connected to each nozzle (4); The third container (3) is configured to contain liquid. The vertical height of the third container (3) is lower than that of the second container (2). The third container (3) is connected to the internal chamber of the second container (2) and is also connected to the first container (1). A water pump is provided between the third container (3) and the first container (1), and the water pump is used to pump the liquid inside the third container (3) into the first container (1); valves are provided between the first container (1) and the second container (2), between the second container (2) and the third container (3), and between the third container (3) and the first container (1); The chamber inside the second container (2) is a regular square prism with eight corners, and also includes eight first connecting pipes (61). One first connecting pipe (61) corresponds to one nozzle (4). The first connecting pipe (61) is connected between its corresponding nozzle (4) and the first container (1). The central axis of the second container is horizontal. The second container has two opposing mounting sidewalls (23) on the central axis. Each mounting sidewall (23) has four first connecting pipes (61) that pass through it to connect with the nozzle (4). The four first connecting pipes (61) located on the same mounting sidewall (23) are parallel to each other, so that the pressure loss generated by the liquid flow through each first connecting pipe (61) is consistent. It also includes eight second connecting pipes (62), which are connected between the second container (2) and the third container (3). Each of the mounting sidewalls (23) has four second connecting pipes (62) connected to the second container (2), and the four second connecting pipes (62) located on the same mounting sidewall (23) are parallel to each other.

2. The three-dimensional isotropic turbulence generation device as described in claim 1, characterized in that, The first container (1) has a vertical central axis and eight first outlets (12). Each first outlet (12) is symmetrical about the central axis of the first container (1) to keep the flow rate and direction of the liquid flowing out from each first outlet (12) consistent. The first connecting pipe (61) is connected to the first container through the first outlets (12).

3. The three-dimensional isotropic turbulence generation device as described in claim 2, characterized in that, The central axis of the second container (2) is horizontal. Each of the mounting sidewalls (23) has four second inlets (21) and four second outlets (22). One second inlet (21) is connected to one nozzle (4). The second outlet is connected to the interior of the second container (2). Each second inlet (21) on each mounting sidewall (23) is symmetrical about the central axis of the second container (2). Each second outlet (22) on each mounting sidewall (23) is symmetrical about the central axis of the second container (2). The first connecting pipe (61) is connected to the nozzle (4) through the second inlet (21). The second connecting pipe (62) is connected to the second container (2) through the second inlet (21).

4. The three-dimensional isotropic turbulence generation device as described in claim 3, characterized in that, The third container (3) has a vertical central axis and eight third inlets (31). Each third inlet (31) is symmetrical about the central axis of the third container (3) to keep the flow rate and direction of the liquid flowing in from each third inlet (31) consistent. The second connecting pipe (62) is connected to the second container (2) through the third inlets (31).

5. The three-dimensional isotropic turbulence generation device as described in claim 4, characterized in that, The nozzle (4) includes a nozzle (41) and a fixing part (42). The fixing part (42) is located at the corner inside the second container (2) and is detachably connected to the second container (2). The nozzle (41) passes through the fixing part (42) and faces the center point of the internal cavity of the second container (2). The fixing part (42) is used to maintain the orientation of the nozzle (41). One nozzle (41) is connected to its corresponding second water inlet (21) through a pipe buried inside the second container (2).

6. The three-dimensional isotropic turbulence generation device as described in claim 5, characterized in that, The second container (2) also includes a box body (24), and each end of the box body (24) on the central axis of the second container (2) is detachably connected to an installation side wall (23). The fixing part (42) is fixedly connected to the installation side wall (23). A sealing layer (231) is provided between the outside of the fixing part (42) and the inner side wall of the box body (24). The sealing layer (231) is fixedly connected to the outside of the fixing part (42).

7. The three-dimensional isotropic turbulence generation device as described in claim 6, characterized in that, The first container (1) has a first inlet (11). The first container (1) includes a first tank body. The first inlet (11) and the first outlet (12) are both located at the bottom of the first tank body. There is only one first inlet (11). The first inlet (11) is located at the center of the bottom of the first tank body. Each first outlet (12) is centrally symmetrical around the first inlet (11). The lower end of the side wall of the first tank body has a flow guide cone (7). The flow guide cone (7) is used to guide and collect the liquid to the middle of the lower wall of the first tank body. The connection between the flow guide cone (7) and the lower wall of the first tank body is around the periphery of each first outlet (12).

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