A narrow-slit resonance wave period measuring device

Abstract

The present invention discloses a narrow-slot resonance wave period measuring device, which is used for measuring the wave period. The main structure includes a wave-facing body, a wave-rearing body, a narrow slot, a wave-transmitting hole, a connecting pipe, a ruler, a handle, etc. The wave-facing body, the wave-rearing body and the narrow slot in the middle together form a narrow-slot resonance system. The wave-transmitting hole at the bottom of the device allows the wave to pass through and generates hydrodynamic interaction with the water body in the narrow slot. The connecting pipe and the ruler are used to measure the wave period. The device of the present invention vertically probes into the wave to be measured to a certain depth. The incident wave passes through the wave-transmitting hole and generates hydrodynamic interaction with the water body in the narrow slot. When the wave height of the water body in the narrow slot reaches the maximum, the natural oscillation period of the water body in the narrow slot is consistent with the incident wave period, and the scale of the ruler aligned with the air-water interface of the connecting pipe indicates the period of the incident wave. The present invention has the significant advantages of novel principle, simple and reliable, good portability and maintenance-free, and provides convenience for the rapid measurement of wave elements.

Description

Technical Field

[0001] The invention belongs to the field of wave parameter measuring instruments or devices, and in particular relates to a narrow-slit resonance wave period measuring device. Background Art

[0002] In the design and construction of ships and marine engineering and hydrodynamic model experiments, the determination of wave elements is one of the most important and complex contents. Wave elements are used to characterize the size and shape of waves, mainly including wave height, wavelength, period, etc. Among them, the wave period refers to the time required for two adjacent wave crests (or troughs) to pass through a fixed observation point. Its value is equal to the quotient of the wavelength and the wave speed, represented by T, and the unit is second (s). At present, the measurement devices or methods for wave elements mainly include visual inspection, wave direction buoy method, pressure wave measurement method, optical wave measurement method, acoustic wave measurement method and radar wave measurement method. However, the sensors used in these wave element measurement devices are more susceptible to interference from visible light, visibility and other environmental factors, resulting in low measurement accuracy. Moreover, most of the devices are relatively complex, prone to failure, and have poor portability.

[0003] According to the hydrodynamic theory of fluid in narrow gaps, when the incident wave frequency (period) is the same as the natural frequency (period) of the water body confined in the narrow gap between the floating bodies, the water body in the narrow gap will produce hydrodynamic resonance. This resonance phenomenon will cause the wave height of the water body in the narrow gap to increase sharply, reaching several times the wave height of the wave to be measured. Using this method, the period of the wave to be measured can be directly measured based on the resonance period of the fluid in the narrow gap. Summary of the invention

[0004] The main purpose of the present invention is to provide a narrow-slit resonance wave period measuring device, which has a novel principle, is simple and reliable, has good portability and is maintenance-free, and can effectively solve the problems of existing measuring devices being susceptible to environmental interference and having a complex structure.

[0005] The specific technical solution adopted by the present invention is as follows:

[0006] A narrow-slit resonance wave period measuring device is used for measuring wave period. The device is a wave element measuring device, and its main structure includes a wave-facing body, a wave-rearward body, a narrow slit, a wave-transmitting hole, a connecting pipe, a ruler, a handle, etc.

[0007] The wave-facing body, the wave-rearing body, the base and the handle form a whole and are integrally formed.

[0008] The wave-facing body and the back-wave body are two groups of rectangular parallelepiped structures with the same shape and size. The narrow slit is a narrow gap located between the wave-facing body and the back-wave body. The gap at the lower end of the narrow slit is connected to the wave-transmitting hole.

[0009] The wave-transmitting hole is located at the lower part of the device and is a hollow cylinder, preferably a rectangular structure. Two opposite walls consistent with the wave propagation direction are open to allow waves to pass through. The gap in the middle of the upper wall of the wave-transmitting hole connected to the lower end of the narrow slit allows waves to pass through. The lower wall of the wave-transmitting hole is the base of the device.

[0010] The connecting tube is a semi-cylindrical, transparent, elongated U-shaped tube with two ends open, and comprises a long tube and a short tube.

[0011] The connecting pipe is fixed on the outer wall of the non-wave-transmitting hole of the narrow-slot resonance wave period measuring device. The end of the long pipe is located at the upper edge of the fixed wall, and the end of the short pipe is slightly higher than the bottom surface of the wave-transmitting hole.

[0012] The scale is fixed on the outer wall of the non-wave-transmitting hole of the narrow-slit resonance wave period measuring device along the long tube of the connecting tube and is arranged parallel to the connecting tube. A series of scale lines marking the wave period are drawn on the scale to indicate the natural oscillation period corresponding to the water body in the narrow slot at different depths, that is, the wave period to be measured.

[0013] The handle is connected to the wave-facing body and the wave-rearward body respectively, and is used by a measuring person to hold the narrow-slit resonance wave period measuring device.

[0014] The working process and principle of the present invention are as follows: the surveyor uses a handle to vertically probe the narrow slit resonance wave period measuring device into the wave to be measured to a certain depth, and makes the wave propagation direction parallel to the wave-transmitting hole wave-transmitting channel. The air-water interface of the connecting pipe is consistent with the probed water depth interface. The water body in the narrow slit oscillates under the hydrodynamic effect of the wave to be measured passing through the wave-transmitting hole. The depth of the narrow slit resonance wave period measuring device probed into the wave is adjusted. When the oscillation wave height of the water body in the narrow slit increases rapidly and reaches the maximum, the resonance state is reached. The scale scale aligned with the air-water interface of the connecting pipe is the reading of the wave period.

[0015] The present invention proposes a narrow-slot resonance wave period measurement device, which changes the natural oscillation period of the water body by changing the water body depth in the narrow slot, and measures the wave period quickly and accurately based on the principle of narrow-slot fluid resonance between floating bodies. Compared with the prior art, the present invention has the significant advantages of novel principle, simple structure, good portability and maintenance-free, and is particularly suitable for wave element measurement in the design and construction of ships and marine engineering and hydraulic model experiments.

[0016] Beneficial effects of the invention: The invention solves the problem that the existing wave element measurement devices or technologies are easily affected by environmental interference and have complex structures, and improves the portability and rapidity of wave period determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a stereogram of a narrow-slit resonance wave period measuring device;

[0018] Figure 2 is a sectional view of the side of the present invention;

[0019] Figure 3 It is a schematic diagram of the connecting pipe in the present invention.

[0020] In the figure, 1-wave-facing body, 2-back wave body, 3-narrow slit, 4-wave-transmitting hole, 5-base, 6-handle, 7-connecting tube, 8-ruler, 9-wave to be measured, 10-air-water interface, 11-oscillation wave crest, 12-long tube of connecting tube, 13-short tube of connecting tube, 14-end of long tube of connecting tube, 15-end of short tube of connecting tube. DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0022] Example: Figure 1 , Figure 2 and Figure 3 As shown, a narrow slot resonance wave period measuring device mainly comprises a wave-facing body 1, a back wave body 2, a narrow slot 3, a wave-transmitting hole 4, a base 5, a handle 6, a connecting pipe 7 and a scale 8.

[0023] The wave-facing body 1, the back-wave body 2, the wave-transmitting hole 4, the base 5, the handle 6, the connecting pipe 7 and the scale 8 form a whole. The wave-facing body 1 and the back-wave body 2 are two sets of rectangular parallelepiped structures with the same shape and size. The narrow slit 3 is located between the wave-facing body 1 and the back-wave body 2, and the lower end is connected to the wave-transmitting hole 4.

[0024] The ratio of the width s of the narrow slit 3 perpendicular to the crest line to the width L of the wave-facing body 1 or the back wave body 2 perpendicular to the crest line must meet a certain range, which mainly depends on the range of the wave period to be measured and needs to be determined through model tests or numerical simulations. Specifically, according to the numerical simulation results of the narrow slit resonance phenomenon of this type of device, for example, for the range of the wave period to be measured: 1.0s≤T≤10.0s, the ratio of s to L satisfies: 0.15≤s / L≤0.20.

[0025] The wave-transmitting hole 4 is a rectangular parallelepiped structure, which is located at the lower part of the device, wherein two opposite walls consistent with the wave propagation direction are open to allow the wave 9 to be measured to pass through. The gap in the middle of the upper wall of the wave-transmitting hole 4 connected to the lower end of the narrow slit 3 allows the wave 9 to be measured to have hydrodynamic effects with the water in the narrow slit 3, and the lower wall of the wave-transmitting hole 4 is the base 5 of the device.

[0026] The connecting tube 7 is a semi-cylindrical, transparent, elongated, U-shaped tube with both ends open, and is composed of a long tube 12 and a short tube 13 to minimize the influence of the measured wave 9 on the air-water interface 10 in the connecting tube 7.

[0027] In this embodiment, it is optimized that the long tube end 14 of the connecting tube is located at the upper edge of the back wave body 2 , and the short tube end 15 of the connecting tube is slightly higher than the lower edge of the base 5 .

[0028] In this embodiment, the diameter of the connecting pipe 7 needs to be within a reasonable range. When the diameter is too large, the air-water interface 10 is affected by the hydrodynamic force of the wave 9 to be measured and is difficult to stabilize; when the diameter is too small, the air-water interface 10 is significantly affected by the surface tension of the liquid, resulting in a large position error of the air-water interface 10. The optimal choice is that the diameter range of the connecting pipe 7 is: 5.0mm-7.5mm.

[0029] The scale 8 is marked with a series of scale lines marking the wave period and is fixed to the outer wall of the back wave body 2 along the connecting tube 12 to indicate the natural oscillation period corresponding to the water body in the narrow gap 3 at different depths, that is, the period of the wave 9 to be measured.

[0030] In this embodiment, under the premise that the cross-sectional area S of the narrow slit 3 parallel to the still water surface has been determined, the resonance period T of the water body in the narrow slit 3 corresponding to different immersion depths D of the measuring device of the present invention (i.e., the wave period to be measured, which is also the wave period value marked by the ruler 8 at different immersion depths D) can be preliminarily determined according to the following formula: Where: g is the acceleration due to gravity.

[0031] The base 5 is located at the bottom of the device and constitutes the lower wall of the wave-transmitting hole 4, providing a partition for the hydrodynamic effect of the wave 9 to be measured, so that the measurement accuracy is not affected by the water depth.

[0032] In a specific embodiment, the dimensions, mass, material, working parameters, etc. of the main structures such as the wave-facing body 1, the back wave body 2, the wave-transmitting hole 4, the base 5, the handle 6, the connecting pipe 7, etc. adopted in the present invention can be adjusted according to the period range of the wave measurement.

[0033] like Figure 1 , Figure 2 and Figure 3As shown, the surveyor vertically probes the narrow slit resonance wave period measuring device into the wave 9 to be measured to a certain depth through the handle 6, and adjusts the direction of the device so that the propagation direction of the wave 9 to be measured passes through the wave-transmitting channel of the wave-transmitting hole 4 in parallel. The air-water interface 10 of the connecting pipe 7 will be flush with the probed water depth interface. The water body confined in the narrow slit 3 will oscillate under the hydrodynamic effect of the wave 9 to be measured passing through the wave-transmitting hole 4. The depth of the adjusting device probed into the water, when the oscillation wave crest 11 of the water body in the narrow slit 3 rises rapidly and reaches the maximum, the water body in the narrow slit 3 and the wave 9 to be measured reach a resonance state. The scale of the ruler 8 aligned with the air-water interface 10 of the connecting pipe 7 indicates the period of the wave 9 to be measured.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A narrow-slit resonance wave period measuring device, characterized in that: It includes a wave-facing body, a back-wave body, a wave-transmitting hole, a connecting pipe and a ruler; the wave-facing body and the back-wave body are arranged in parallel front and back, the wave-transmitting hole is arranged at the lower part of the wave-facing body and the back-wave body, a gap is arranged at the upper part of the wave-transmitting hole, the connecting pipe is fixed on the outer wall surface of the non-wave-transmitting hole of the narrow-slit resonance wave period measuring device, the ruler is arranged in parallel with the connecting pipe, a series of scale lines marking the wave period are drawn on the ruler, the ruler is fixed on the outer wall surface of the back-wave body along the long tube of the connecting pipe, and is used to indicate the natural oscillation period corresponding to the water body in the narrow slot at different depths; the wave-facing body and the back-wave body are two groups of rectangular structures with the same shape and size, there is a narrow slot in the middle of the wave-facing body and the back-wave body, and the lower end of the narrow slot is connected with the wave-transmitting hole.

2. The narrow-slit resonance wave period measuring device according to claim 1, characterized in that: The wave-transmitting hole is a hollow cylinder, and its axis is parallel to the arrangement direction of the wave-facing body and the back-wave body.

3. The narrow-slit resonance wave period measuring device according to claim 1, characterized in that: The connecting pipe is a U-shaped pipe with two ends opened, including a long pipe and a short pipe.

4. The narrow-slit resonance wave period measuring device according to claim 3 is characterized in that: The end of the long tube is located at the upper edge of the fixed wall surface, and the end of the short tube is slightly higher than the bottom surface of the wave-transmitting hole.

5. The narrow-slit resonance wave period measuring device according to claim 4 is characterized in that: The connecting tube is a semi-cylindrical elongated transparent tube, and the diameter range of the connecting tube is: 5.0mm-7.5mm.

6. The narrow-slit resonance wave period measuring device according to claim 1, characterized in that: It also includes a base, which is located at the bottom of the wave-transmitting hole and provides a partition for the hydrodynamic influence of the waves to be measured.

7. The narrow-slit resonance wave period measuring device according to claim 1, characterized in that: It also includes a handle, which is fixed on the wave-facing body and the back-wave body.

8. The narrow-slit resonance wave period measuring device according to any one of claims 1 to 7, characterized in that: The wave-transmitting hole, the wave-facing body, the wave-rearward body and the base are integrally formed.

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