Design method of spoiler pipe structure based on karman vortex street theory

Abstract

The application provides a design method of a spoiler pipe structure based on a Karman vortex street theory, the spoiler pipe structure comprising a liquid conveying pipe and a variable-diameter spoiler arranged in the liquid conveying pipe, the variable-diameter spoiler comprising a spoiler spiral wire wound in a liquid flow direction and having a wire diameter d, the design method comprising the following steps: obtaining an initial calculation formula of the wire diameter d according to a Reynolds number calculation formula; obtaining a calculation formula of a fluid inlet pipe flow rate V2 of the liquid conveying pipe according to a flow conservation calculation formula; and obtaining a final calculation formula of the wire diameter d according to a calculation formula among a liquid pump piston speed V1, a motor rotating speed n, an eccentric distance R of an eccentric wheel and a length-diameter ratio λ of a connecting rod. The application can more easily cause vortexes in the two side regions of the spoiler spiral wire along the radial direction of the liquid conveying pipe, and then more easily cause the liquid to mix along the radial direction of the conveying pipe, so that the spoiler efficiency and mixing degree of the oral cavity flushing liquid in the liquid conveying pipe are further improved.

Description

Technical Field

[0001] This invention relates to the field of oral cleaning technology, and in particular to a design method for a turbulence-prone pipeline structure based on the Karman vortex street theory. Background Technology

[0002] Currently, springs are placed in heating modules to improve heat transfer efficiency. These are mostly fixed-diameter springs, which have limited effect in large-diameter heating pipes.

[0003] like Figure 1 and Figure 2 As shown, existing heating modules typically include a heating pipe 01 and an electric heating spring 02 located within the heating pipe 01. The outer diameter of the spring coil of the electric heating spring 02 is uniform along the length of the heating pipe 01. This results in the water flow at the center of the inner cavity of the heating pipe 01 not being heated, leading to uneven heating or fluctuating temperatures in the water flowing out of the heating pipe 01. Furthermore, existing electric heating modules often use metal for heat conduction, which poses a risk of electric leakage upon contact with water. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a design method for a turbulent pipeline structure based on the Karman vortex street theory, which can more easily induce vortices in both sides of the turbulent spiral wire along the radial direction of the liquid delivery pipe, thereby making it easier for the liquid to mix along the radial direction of the delivery pipe, and thus further improving the turbulence efficiency and mixing degree of the oral irrigation fluid in the liquid delivery pipe.

[0005] To address the aforementioned technical problems, this invention provides a design method for a flow-turbulence pipeline structure based on the Karman vortex street theory. The flow-turbulence pipeline structure includes a liquid delivery pipe and a variable-diameter flow-turbulence element disposed within the liquid delivery pipe. The variable-diameter flow-turbulence element comprises a flow-turbulence spiral wire wound along the liquid flow direction with a diameter of d, where d = Re·v / V², and Re is the Reynolds number, with a value range of 60. <Re<2×10 5 v is the kinematic viscosity of the fluid, and V2 is the fluid velocity at the inlet of the liquid delivery pipe.

[0006] Preferably, when the design method is applied to a water flosser, the turbulence-disrupting pipeline structure is located downstream of the pump assembly of the water flosser, and the calculation method for the wire diameter d includes the following steps:

[0007] According to the flow conservation formula V1A1=V2A2, the formula for calculating the fluid inlet velocity V2 of the liquid delivery pipe (1) is: V2=V1A1 / A2;

[0008] The calculation formula is based on the piston speed V1 of the liquid pump, the motor speed n, the eccentric wheel speed n', the gear ratio i, the eccentric wheel eccentricity R, and the length-to-diameter ratio λ of the connecting rod:

[0009] ω=2πn′,

[0010] n' = n / i,

[0011]

[0012] V 1max =ωR;

[0013] The final formula for calculating the wire diameter d is derived as follows:

[0014]

[0015]

[0016] Where d is the wire diameter. min —Minimum wire diameter; Re—Reynolds number; V1—Pump piston speed, which is approximately equal to the initial fluid velocity; V2—Fluid inlet velocity of the liquid delivery pipe; v—Kinematic viscosity; A1—Flow cross-sectional area of ​​the pump chamber; A2—Flow cross-sectional area of ​​the liquid delivery pipe chamber; r1—Pump chamber radius; r2—Inlet radius of the liquid delivery pipe; ω—October angular velocity of the eccentric wheel; n—Motor speed; R—Eccentric wheel eccentricity; λ—Connecting rod length-to-diameter ratio.

[0017] Preferably, the turbulence spiral wire includes N constant diameter spiral sections and M variable diameter spiral sections arranged along the liquid flow direction of the liquid conveying pipe. When N=1, M>0; when N>1, M≥0. The spiral diameter of a single constant diameter spiral section remains constant along the liquid flow direction of the liquid conveying pipe, and the spiral diameters of two adjacent constant diameter spiral sections are different. The spiral diameter of the variable diameter spiral section changes along the liquid flow direction of the liquid conveying pipe.

[0018] Preferably, the diameter of the liquid delivery pipe is D, and the distance between the largest diameter section of the constant diameter spiral part and the wall of the liquid delivery pipe is 0 to 0.25D.

[0019] Preferably, the distance between the largest diameter section of the constant diameter spiral section and the wall of the liquid delivery pipe is d to 0.25D.

[0020] Preferably, the diameter of the liquid delivery pipe is D, and the inner diameter of the smallest segment of the constant diameter spiral section is 0 to 0.5D.

[0021] Preferably, the inner diameter of the smallest segment of the constant diameter spiral section is 2d to 0.5D.

[0022] Preferably, the diameter of the liquid delivery pipe is D, the distance between the variable diameter spiral section and the wall of the liquid delivery pipe is 0 to 0.25D, and the minimum inner diameter of the variable diameter spiral section is 0 to 0.5D.

[0023] Preferably, the distance between the variable diameter spiral section and the wall of the liquid delivery pipe is d to 0.25D.

[0024] Preferably, the minimum inner diameter of the variable diameter spiral section is 2d to 0.5D.

[0025] As described above, the design method for the turbulence-prone pipe structure based on the Karman vortex street theory of the present invention has the following beneficial effects: The multiple helical segments of the variable-diameter turbulence-prone element with a diameter of d, designed by the above method, are distributed at different radial positions in the liquid delivery pipe. Specifically, the helical segment with the largest diameter is used to turbulent the fluid near the wall, the helical segment with the smallest diameter is used to turbulent the fluid at the center, and the helical segments with diameters of other sizes are used to turbulent the fluid at the remaining positions. More importantly, vortices are more easily generated on both sides of the turbulence-prone spiral wire along the radial direction of the liquid delivery pipe, thus making it easier for the liquid to mix radially along the delivery pipe, thereby improving the turbulence efficiency and mixing degree of the oral irrigating fluid in the liquid delivery pipe 1. Therefore, the variable-diameter turbulence-prone element designed by the design method for the turbulence-prone pipe structure based on the Karman vortex street theory of the present invention can more easily generate vortices on both sides of the turbulence-prone spiral wire along the radial direction of the liquid delivery pipe, thus making it easier for the liquid to mix radially along the delivery pipe, thereby further improving the turbulence efficiency and mixing degree of the oral irrigating fluid in the liquid delivery pipe. Attached Figure Description

[0026] Figure 1 Shown is a cross-sectional view of a heating module in the prior art;

[0027] Figure 2 The image shown is a 3D view of an electrothermal spring in the prior art;

[0028] Figure 3 Shown is a front view of the turbulence-disrupting pipeline structure of the present invention;

[0029] Figure 4 The diagram shown is a cross-sectional view of the turbulence-disrupting pipeline structure of the present invention.

[0030] Figure 5 Shown is a front view of a first embodiment of the variable diameter spoiler;

[0031] Figure 6 Shown is a front view of a second embodiment of the variable diameter spoiler;

[0032] Figure 7 This is a schematic diagram of the turbulent kinetic energy of an existing spring.

[0033] Figure 8 The diagram shows the turbulent kinetic energy of the first type of straight-through spring obtained by the design method of this invention.

[0034] Figure 9 The diagram shows the turbulent kinetic energy of the first type of variable diameter spring obtained by the design method of this invention.

[0035] Figure 10 The diagram shows the turbulent kinetic energy of the second type of straight-through spring obtained by the design method of this invention.

[0036] Figure 11 This diagram illustrates the turbulent kinetic energy of the second type of variable-diameter spring obtained by the design method of this invention.

[0037] Component designation explanation

[0038] 01 Heating pipes

[0039] 02 Heating Spring

[0040] 1. Liquid delivery pipe

[0041] 11 Liquid Inlet End

[0042] 12. Liquid outlet end

[0043] 2. Variable diameter spoiler

[0044] 21. Turbulence-inducing spiral wire

[0045] 211 Constant Diameter Spiral Section

[0046] 211a Large-diameter spiral section

[0047] 211b Small-diameter spiral section

[0048] 211c Medium Bore Spiral Section

[0049] 212 Variable Diameter Spiral Section Detailed Implementation

[0050] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0051] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0052] like Figure 3 , Figure 4 , Figure 5 as well as Figure 6 As shown, the flow-disrupting pipeline structure of the present invention includes a liquid delivery pipe 1 and a variable-diameter flow-disrupting element 2 disposed within the liquid delivery pipe 1. The liquid delivery pipe 1 has an inlet end 11 and an outlet end 12. The diameter of the liquid delivery pipe 1 is D, the radius of its inlet end 11 is r2, and the flow cross-sectional area of ​​the inlet end 11 of the liquid delivery pipe 1 is A2 = πr2. 2 The variable diameter turbulence-disrupting component 2 includes a turbulence-disrupting spiral wire 21 wound along the liquid flow direction with a wire diameter of d. The turbulence-disrupting spiral wire 21 may have turbulence-disrupting protrusions or be in the form of a smooth filament.

[0053] The water flosser of this invention includes a motor, an eccentric wheel, a liquid pump, a connecting rod, and the aforementioned turbulence-prone piping structure. The motor rotates at a speed of n; the eccentric wheel is connected to the motor's drive shaft via a pinion gear, the eccentric wheel rotates at a speed of n', the eccentricity of the eccentric wheel is R, and the angular velocity of the eccentric wheel is ω; the liquid pump includes a cylinder and a piston reciprocating within the cylinder, the cylinder being connected to the inlet end 11 of the liquid delivery pipe 1, the pump chamber radius of the cylinder being r1, and the flow cross-sectional area of ​​the pump chamber being A1 = πr1. 2 The connecting rod has an annular structure at its bottom that mates with the eccentric protrusion of the eccentric wheel, fitting onto the eccentric wheel. The connecting rod head is connected to the piston, and the length-to-diameter ratio of the connecting rod is λ. Furthermore, the oral irrigating fluid has kinematic viscosity, which is the ratio of the fluid's dynamic viscosity to its density ρ at the same temperature, expressed in units of (m²) / s and denoted by the lowercase letter v. Kinematic viscosity v is temperature-dependent; see Table 1.

[0054] Table 1. Relationship between kinematic viscosity and temperature

[0055] Temperature ℃ Kinematic viscosity v[m^2 / s] 30 8.009E-07 31 7.853E-07 32 7.697E-07 33 7.542E-07 34 7.386E-07 35 7.230E-07 36 7.100E-07 37 6.970E-07 38 6.840E-07 39 6.710E-07 40 6.580E-07

[0056] Based on the above technical foundation, the present invention provides a design method for a spoiler pipeline structure based on the Karman vortex street theory, including the following steps:

[0057] According to the Reynolds number calculation formula: The initial calculation formula for the wire diameter d is obtained: d = Re·v / V2, where: Re is the Reynolds number, and the value range of the Reynolds number is: 60 < Re < 2×10 5 , v is the kinematic viscosity of the fluid, and V2 is the fluid velocity at the inlet of the liquid delivery pipe.

[0058] When the design method is applied to a dental irrigator and the spoiler pipeline structure is arranged downstream of the pump assembly of the dental irrigator, the calculation method for the wire diameter d includes the following steps:

[0059] According to the flow conservation calculation formula V1A1 = V2A2, the calculation formula for the fluid inlet velocity V2 of the liquid delivery pipe 1 is obtained: V2 = V1A1 / A2;

[0060] According to the calculation formulas between the liquid pump piston velocity V1, the motor speed n, the eccentric wheel speed n’, the gear transmission ratio i, the eccentric distance R of the eccentric wheel, and the connecting rod length-diameter ratio λ:

[0061] ω = 2πn ′ ,

[0062] n′ = n / i,

[0063]

[0064] V 1max = ωR;

[0065] The final calculation formula for the wire diameter d is obtained:

[0066]

[0067]

[0068] where, d—the wire diameter, d min —the minimum wire diameter; Re—the Reynolds number. When 60 < Re < 500, vortices start to shed inside the liquid delivery pipe. When 500 < Re < 2×10 5 , stable vortices shed inside the liquid delivery pipe; V—the flow velocity, V1—the liquid pump piston velocity, the liquid pump piston velocity is approximately equal to the fluid velocity out of the pump, V2—the fluid inlet velocity of the liquid delivery pipe; v—the kinematic viscosity; A—the pipeline cross-sectional area, A1—the cross-sectional area of the pump chamber of the liquid pump, A2—the cross-sectional area of the pipe cavity at the liquid inlet end of the liquid delivery pipe; r1—the radius of the pump chamber of the liquid pump, r2—the radius of the liquid inlet end of the liquid delivery pipe; ω—the angular velocity of the eccentric wheel; n—the motor speed, n’—the speed of the eccentric wheel; R—the eccentric distance of the eccentric wheel; λ—the connecting rod length-diameter ratio.

[0069] In this invention, the liquid delivery pipe 1 is used to deliver oral rinsing fluid. The inlet end 11 of the liquid delivery pipe 1 can be connected to the liquid storage container of the oral irrigator, and the outlet end 12 of the liquid delivery pipe 1 can be connected to the oral rinsing handle of the oral irrigator. The turbulence spiral wire 21 of the variable diameter turbulence element 2 is wound along the liquid flow direction of the liquid delivery pipe 1. The innovation of the design method of this invention lies in the wire diameter design of the turbulence spiral wire 21 of the variable diameter turbulence element 2:

[0070] First, according to the Reynolds number calculation formula: The initial calculation formula for wire diameter d is derived as: d = Re·v / V;

[0071] Next, based on the flow conservation formula V1A1=V2A2, the formula for calculating the fluid inlet velocity V2 of liquid delivery pipe 1 is obtained: V2=V1A1 / A2;

[0072] The calculation formula is based on the piston speed V1 of the liquid pump, the motor speed n, the eccentric wheel speed n', the gear ratio i, the eccentric wheel eccentricity R, and the length-to-diameter ratio λ of the connecting rod:

[0073] ω=2πn′,

[0074] n′=n / i

[0075]

[0076] V 1max =ωR;

[0077] Finally, the final formula for calculating the wire diameter d is derived:

[0078]

[0079]

[0080] The variable-diameter turbulence-disrupting element 2, designed using the above method, has multiple helical segments of diameter d distributed at different radial positions in the liquid delivery pipe 1. Specifically, the helical segment with the largest diameter disturbs the fluid near the wall, the helical segment with the smallest diameter disturbs the fluid at the center, and the helical segments with the remaining diameters disturb the fluid in the remaining positions. More importantly, the turbulence-disrupting spiral wire 21 more easily generates vortices on both sides of the radial direction of the liquid delivery pipe 1, thus facilitating mixing of the liquid along the radial direction of the delivery pipe 1, thereby improving the turbulence efficiency and mixing uniformity of the oral irrigation fluid within the liquid delivery pipe 1.

[0081] Therefore, the variable-diameter spoiler 2 designed by the design method of the spoiler pipeline structure based on the Karman vortex street theory of the present invention can more easily trigger vortices in the two side regions along the radial direction of the liquid delivery pipe 1 by the spoiler spiral wire 21, and thus more easily mix the liquid along the radial direction of the delivery pipe 1, thereby further improving the spoiler efficiency and mixing degree of the oral irrigation liquid in the liquid delivery pipe 1.

[0082] Generally, when the temperature of the oral cleaning liquid used in the above-mentioned oral irrigator is 35±2°C, the user's oral comfort is relatively good. When the reciprocating frequency of the piston of the liquid pump is 25 Hz, the maximum speed V of the piston 1max = 0.4398 m / s, the radius r2 of the liquid inlet end 11 of the liquid delivery pipe 1 is 3 mm, the lumen diameter D of the liquid delivery pipe 1 is 8 mm, the pump cavity radius r1 of the cylinder block of the liquid pump is 4.025 mm, and the liquid flow rate V2 at the liquid inlet end 11 of the liquid delivery pipe 1 is approximately 0.7917 m / s. When 60 < Re < 500, the wire diameter d ≥ 0.057 mm; when 500 < Re < 2×10 5 ³, the wire diameter d ≥ 0.476 mm.

[0083] To improve the spoiler effect of the above-mentioned spoiler spiral wire 21, the spoiler spiral wire 21 includes N sections of constant-diameter spiral parts 211 and M sections of variable-diameter spiral parts 212 arranged along the liquid flow direction of the liquid delivery pipe 1. When N = 1, M > 0; when N > 1, M ≥ 0; the spiral diameter of a single section of the constant-diameter spiral part 211 remains constant along the liquid flow direction of the liquid delivery pipe 1, the spiral diameters of adjacent two sections of the constant-diameter spiral parts 211 are different, and the spiral diameter of the variable-diameter spiral part 212 changes along the liquid flow direction of the liquid delivery pipe 1..

[0084] Since the lumen diameter of the above-mentioned liquid delivery pipe 1 is D, the distance between the largest-diameter section of the constant-diameter spiral part 211 and the pipe wall of the liquid delivery pipe 1 is 0 to 0.25D, which can trigger vortices at the outer edge of the largest-diameter section of the constant-diameter spiral part 211. Further, the distance between the largest-diameter section of the constant-diameter spiral part 211 and the pipe wall of the liquid delivery pipe 1 is d to 0.25D, which can more easily trigger vortices at the outer edge of the largest-diameter section of the constant-diameter spiral part 211.

[0085] The inner diameter of the smallest-diameter section of the constant-diameter spiral part 211 is 0 to 0.5D, which can trigger vortices at the central core of the smallest-diameter section of the constant-diameter spiral part 211. Further, the inner diameter of the smallest-diameter section of the constant-diameter spiral part 211 is 2d to 0.5D, which can more easily trigger vortices at the central core of the smallest-diameter section of the constant-diameter spiral part 211.

[0086] For example, as Figure 5As shown, the constant diameter spiral section 211 is one of a large diameter spiral section 211a, a medium diameter spiral section 211c, and a small diameter spiral section 211b. The distance between the large diameter spiral section 211a and the wall of the liquid conveying pipe 1 is 0 to 0.25D.

[0087] To allow for better space for the development of turbulence and eddies between the outer edge of the large-diameter spiral section 211a and the wall of the liquid delivery pipe 1, the distance between the large-diameter spiral section 211a and the wall of the liquid delivery pipe 1 is d to 0.25D. When the distance between the large-diameter spiral section 211a and the wall of the liquid delivery pipe 1 is 0.25D, the eddies in the turbulence spiral wire 21 develop uniformly in both radial regions of the liquid delivery pipe 1. Specifically, when the large-diameter spiral section 211a is close to the wall of the liquid delivery pipe 1, it is equivalent to the turbulence spiral wire 21 being in the near-wall boundary layer of the fluid. When the flow velocity is low, the turbulence effect is extremely weak and it only affects the near-wall boundary layer. It has almost no disturbance effect on the high-speed liquid located in the central core of the liquid delivery pipe 1. When the distance between the outer edge of the large-diameter spiral section 211a and the wall of the liquid delivery pipe 1 is at least d, the turbulence spiral wire 21 disturbs the medium and high-speed liquids, thereby forming turbulence, which affects the near-wall boundary layer and improves the heat transfer efficiency of the liquid delivery pipe 1 for the oral cleaning fluid.

[0088] In order to generate a vortex at the center core of the liquid delivery pipe 1, the constant diameter spiral section 211 is one of a large diameter spiral section 211a, a medium diameter spiral section 211c, and a small diameter spiral section 211b, with the inner diameter of the small diameter spiral section 211b being 0 to 0.5D.

[0089] In order to allow for better development space for turbulence and eddies in the aforementioned small-diameter spiral section 211b, the inner diameter of the aforementioned small-diameter spiral section 211b is 2d to 0.5D.

[0090] Similarly, the diameter of the liquid delivery pipe 1 is D, the distance between the variable diameter spiral portion 212 and the wall of the liquid delivery pipe 1 is 0 to 0.25D, and the minimum inner diameter of the variable diameter spiral portion 212 is 0 to 0.5D. Further, the distance between the variable diameter spiral portion 212 and the wall of the liquid delivery pipe 1 is d to 0.25D. The minimum inner diameter of the variable diameter spiral portion 212 is 2d to 0.5D.

[0091] The aforementioned turbulence spiral wire 21 can be made of either a non-elastic material or an elastic material.

[0092] Then, the specific turbulence effect of the turbulence spiral wire 21 with a wire diameter of d in this invention is simulated and analyzed: the turbulence spiral wire 21 is formed by winding metal wire. For example, a straight-through spring and a variable-diameter spring with a wire diameter of 0.8 mm can be obtained by the design method of this invention, or a straight-through spring and a variable-diameter spring with a wire diameter of 1.0 mm can be obtained by the design method of this invention.

[0093] This invention performs simulation calculations on existing straight springs, straight-through springs and variable-diameter springs with a wire diameter of 0.8mm, and straight-through springs and variable-diameter springs with a wire diameter of 1.0mm. The flow field parameters "turbulent kinetic energy," "turbulence intensity," and "average velocity" are analyzed, and the results are shown in Table 2.

[0094] Table 2 Comparison of Turbidity among Existing Straight Springs, Through-Type Springs, and Variable Diameter Springs

[0095]

[0096] The formula relating turbulent kinetic energy k to turbulence intensity I is: Where v represents velocity. Meanwhile, a greater turbulence intensity indicates a more mature turbulence development, which is a positive indicator of heat transfer efficiency. Simulation results (i.e., data in Table 2) show that the turbulence intensity under the action of straight-through springs with 0.8mm wire diameter and variable-diameter springs with 1.0mm wire diameter is greater than that of existing straight springs. Furthermore, as the wire diameter d increases, the turbulence effect is enhanced, turbulence development is more intense, and heat transfer efficiency is higher.

[0097] Figure 7 , Figure 8 , Figure 9 , Figure 10 as well as Figure 11 This is a schematic diagram of the turbulent kinetic energy within the liquid delivery pipe 1 under the action of five different springs.

[0098] From the turbulent kinetic energy diagram, we can conclude that:

[0099] 1. The turbulent kinetic energy of a straight-through spring with a wire diameter of 0.8mm (obtained by the design method of this invention) is 0.087-0.232m. 2 / s 2 The turbulent kinetic energy of a variable-diameter spring with a wire diameter of 1.0 mm (obtained by the design method of this invention) is 0.087-0.290 m. 2 / s 2 The turbulent kinetic energy of existing straight springs is 0.058-0.087 m. 2 / s 2 That is, the turbulent kinetic energy of the straight-through spring and the variable-diameter spring obtained by the design method of the present invention is greater than that of the existing straight spring.

[0100] 2. The variable diameter spring can disturb the high-speed liquid in the central core area of ​​the liquid delivery pipe 1, while the straight-through spring mainly affects the area near the wall of the liquid delivery pipe 1, and has a weaker effect on the liquid in the central core area of ​​the liquid delivery pipe 1, which may result in temperature fluctuations.

[0101] 3. If the portion of the variable diameter spring whose spiral diameter gradually decreases along the direction of liquid flow is arranged near the inlet end 11 of the liquid conveying pipe 1, it can further agitate the fluid in the liquid conveying pipe 1 and improve the heat transfer efficiency.

[0102] Finally, the specific turbulence effect of the turbulence spiral wire 21 with a diameter of d of the present invention was tested and analyzed:

[0103] To further verify the effect of variable diameter springs on heat transfer efficiency, this invention conducted experimental tests: Samples of both straight-through and variable diameter springs with a wire diameter of 0.8 mm were made and installed in water flossers No. 1, 2, 3, and 4 for temperature rise testing. The stable water temperature at each setting was recorded, and the statistical results are shown in Table 3. In Table 3, the cold water temperature is 16±1℃, and the room temperature water temperature is 25±1℃.

[0104] Table 3. Water Temperature Fluctuation of Straight-through Springs and Variable-diameter Springs

[0105]

[0106]

[0107] The temperature comparison between the No. 1 and No. 2 water flossers mentioned above is shown in Table 4:

[0108] Table 4. Temperature Comparison of Straight-through and Variable-diameter Springs for Flossers No. 1 and No. 2

[0109]

[0110] Please refer to Table 5 for a temperature comparison between the No. 3 and No. 4 oral irrigators mentioned above:

[0111] Table 5. Temperature Comparison of Water Flossers No. 3 and No. 4

[0112]

[0113] The test results of No. 1 and No. 2 water flossers show that the difference in stable temperature between different settings of the 0.8mm variable diameter spring is less than that of the 0.8mm straight-through spring. This means that the 0.8mm variable diameter spring has a more stable heat transfer efficiency for water flow at different settings than the straight-through spring of the same wire diameter.

[0114] The test results of water flossers No. 3 and No. 4 show that the difference in stable temperature at each setting of the 0.8mm variable diameter spring is significantly smaller than that of the existing straight spring. This means that the 0.8mm variable diameter spring has a heat transfer efficiency that is several times higher than that of the existing straight spring for water flow at different settings.

[0115] Therefore, the test results are consistent with the simulation results.

[0116] In summary, the variable-diameter turbulence-inducing component designed in this invention can more easily generate vortices on both sides of the turbulence-inducing spiral wire along the radial direction of the liquid delivery pipe, thereby making it easier for the liquid to mix radially along the delivery pipe, and thus further improving the turbulence efficiency and mixing degree of the oral irrigation fluid in the liquid delivery pipe. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0117] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A design method for a turbulent pipeline structure based on the von Kármán vortex street theory, characterized in that, The turbulence-disrupting pipeline structure includes a liquid delivery pipe (1) and a variable diameter turbulence-disrupting component (2) disposed in the liquid delivery pipe (1). The variable diameter turbulence-disrupting component (2) includes a turbulence-disrupting spiral wire (21) wound along the liquid flow direction with a wire diameter of d. Where Re is the Reynolds number, and the range of the Reynolds number is 60. <Re<2×10 5 , V1 is the kinematic viscosity of the fluid, and V2 is the fluid velocity at the inlet of the liquid delivery pipe. When the design method is applied to a dental flosser, the turbulence-inducing pipeline structure is located downstream of the pump assembly of the dental flosser. The calculation method for the wire diameter d includes the following steps: According to the formula for flow conservation The formula for calculating the fluid inlet velocity V2 of the liquid delivery pipe (1) is derived as follows: ; Based on the piston speed of the liquid pump Motor speed n, eccentric wheel speed n', gear ratio i, eccentric wheel eccentricity R, and connecting rod length-to-diameter ratio The calculation formula between them is: ， ， ， ； The final formula for calculating the wire diameter d is derived as follows: ， ； Where d is the wire diameter. —Minimum wire diameter; Re —Reynolds number, —Liquid pump piston speed, which is approximately equal to the initial velocity of the fluid. —Maximum speed of the piston —The fluid inlet velocity of the liquid delivery pipe; —Kinematic viscosity; —The cross-sectional area of ​​the pump chamber of a liquid pump. —The cross-sectional area of ​​the liquid delivery pipe's lumen; —The radius of the pump chamber of the liquid pump, —The radius of the inlet end of the liquid delivery pipe; — angular velocity of the eccentric wheel; n — motor speed; i — gear ratio; R — eccentricity of the eccentric wheel; —Connecting rod length-to-diameter ratio.

2. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 1, characterized in that: The turbulence spiral wire (21) includes N constant diameter spiral sections (211) and M variable diameter spiral sections (212) arranged along the liquid flow direction of the liquid conveying pipe (1). When N=1, M>0; when N>1, M≥0. The spiral diameter of a single constant diameter spiral section (211) remains constant along the liquid flow direction of the liquid conveying pipe (1), and the spiral diameters of two adjacent constant diameter spiral sections (211) are different. The spiral diameter of the variable diameter spiral section (212) changes along the liquid flow direction of the liquid conveying pipe (1).

3. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 2, characterized in that: The diameter of the liquid delivery pipe (1) is D, and the distance between the largest diameter section of the constant diameter spiral part (211) and the wall of the liquid delivery pipe (1) is 0 to 0.25D.

4. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 3, characterized in that: The distance between the largest diameter section of the constant diameter spiral section (211) and the wall of the liquid delivery pipe (1) is d ~ 0.25D.

5. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 2, characterized in that: The diameter of the liquid delivery pipe (1) is D, and the inner diameter of the smallest section of the constant diameter spiral part (211) is 0 to 0.5D.

6. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 5, characterized in that: The inner diameter of the smallest segment of the constant diameter spiral section (211) is 2d to 0.5D.

7. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 2, characterized in that: The diameter of the liquid delivery pipe (1) is D, the distance between the variable diameter spiral part (212) and the wall of the liquid delivery pipe (1) is 0 to 0.25D, and the minimum inner diameter of the variable diameter spiral part (212) is 0 to 0.5D.

8. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 7, characterized in that: The distance between the variable diameter spiral section (212) and the wall of the liquid delivery pipe (1) is d ~ 0.25D.

9. The design method for a turbulent pipeline structure based on the Karman vortex street theory according to claim 7, characterized in that: The minimum inner diameter of the variable diameter spiral section (212) is 2d to 0.5D.

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