CN112098272A - Method and device for simultaneously measuring surface tension and viscosity of liquid on line - Google Patents
Method and device for simultaneously measuring surface tension and viscosity of liquid on line Download PDFInfo
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Abstract
The invention discloses a method for simultaneously measuring the surface tension and the viscosity of a liquid on line, which comprises the following steps: the liquid drop generating unit generates liquid drops oscillating in a second-order mode; the laser irradiates the oscillated liquid drop and the motion trail thereof to generate a rainbow signal; recording a rainbow image of the oscillating ellipsoidal droplets to spherical droplets when a steady state is formed; obtaining a calibration curve of pixel columns and scattering angles; extracting signals in the rainbow image, corresponding to the calibration curve, and inverting the rainbow image to obtain the refractive index and the radius of the spherical liquid drop; then obtaining the evolution situation of the ellipsoid degree in the falling process of the liquid drop according to the rainbow angle deviation of the rainbow image; and converting the ellipsoid degree into oscillation amplitude information, fitting to obtain the oscillation frequency and the time constant of the damping oscillation function, and respectively obtaining the surface tension and viscosity value of the liquid. The invention also discloses a device for simultaneously measuring the surface tension and the viscosity of the liquid on line. The method and the device realize the tracking of microsecond-order liquid drop oscillation and improve the space-time resolution of measurement.
Description
Technical Field
The invention relates to the field of liquid thermophysical property online measurement, in particular to a method and a device for simultaneously measuring the surface tension and the viscosity of a liquid on line.
Background
Surface tension and viscosity are important physicochemical properties of liquids and are the fundamental data commonly used in many scientific research and engineering applications such as medicine, food, fuel atomization and multiphase reactions. The current common methods for measuring the surface tension and viscosity of liquids are: a capillary rise method in which a liquid is driven to flow through a capillary by an external pressure, and the surface tension and viscosity of the liquid are estimated by measuring the height of the liquid in the capillary and the liquid flow rate; the maximum bubble method, which measures the inner radius of the capillary when the pressure in the bubble is maximum; drop weight method, which measures the mass of a drop of liquid when it is dropped from a capillary. The common problems of the methods are that the sample consumption is large, the contact measurement is easy to cause sample pollution, the determination time is long, and the like. The capillary rise method is a static method in terms of time resolution of measurement, and other methods can be used for measuring dynamic surface tension, but the time accuracy can only reach 1ms at most.
The oscillating liquid drop method obtains the surface tension and viscosity value of the liquid by observing the form and time evolution of the oscillating liquid drop formed after jet flow cracking, the time resolution can reach microsecond magnitude, and the method can be used for measuring the dynamic interface parameters of the liquid. For example, chinese patent publication No. CN108007825A discloses a method for testing liquid viscosity based on mechanical vibration of liquid droplets, which specifically includes the following steps: placing a hydrophobic substrate on an ultrasonic probe of a Doppler ultrasonic instrument, and generating liquid drops on the hydrophobic substrate through a micro-injector; the liquid drops are vibrated through a vibration trigger device with an automatic rebound function, and then the vibration trigger device rebounds, so that the liquid drops freely vibrate; the ultrasonic probe converts the free vibration of capillary waves on the surface of the liquid drop into an ultrasonic Doppler frequency shift signal by adopting a non-focusing continuous wave Doppler method and amplifies the ultrasonic Doppler frequency shift signal; the computer signal processing module collects and processes the Doppler frequency shift signal to obtain a free vibration characteristic diagram of the liquid drop; and fitting the free vibration characteristic diagram to obtain the attenuation rate of the liquid drop amplitude along with time, and further calculating to obtain the liquid viscosity. In addition, the oscillating droplet method is also suitable for liquid parameter measurement under extreme conditions (super-cooling, high-temperature and high-pressure environments). At present, the liquid drop form change is observed by adopting direct imaging methods such as high-speed photography and the like, but the method is limited by the pixel size and the view field size, the liquid drop contour needs to be fitted, and the data processing is more complex. Therefore, the development of a rapid, efficient, accurate and reliable online measuring method and device for the dynamic surface tension and viscosity of the liquid has very important scientific significance and practical value.
Disclosure of Invention
In view of the superiority of the oscillating liquid drop method for measuring the liquid interface parameters, the invention aims to provide a method and a device for simultaneously measuring the surface tension and the viscosity of liquid on line, thereby realizing the tracking of microsecond-order liquid drop oscillation and improving the time-space resolution of measurement.
In order to achieve the purpose, the invention provides the following technical scheme:
a method for simultaneously measuring the surface tension and the viscosity of a liquid on line comprises the following steps:
(1) the liquid drop generating unit generates liquid drops oscillating in a second-order mode, and the cross section of each liquid drop is ellipsoidal;
(2) the laser beam expanding unit generates sheet laser and irradiates the oscillated liquid drop and the motion trail thereof to generate a rainbow signal; the signal processing and collecting unit records the oscillating ellipsoid liquid drop to form a rainbow image of the spherical liquid drop in a stable state;
(3) calibrating the rainbow signal height and the scattering angle in the rainbow image to obtain a calibration curve of a pixel column and the scattering angle; extracting signals in the rainbow image, corresponding to the calibration curve, and inverting the rainbow image in a steady state to obtain the refractive index and the radius of the spherical liquid drop;
(4) combining the refractive index and the radius of the spherical liquid drop, and obtaining the evolution condition of the ellipsoid degree in the liquid drop falling process according to the rainbow angle deviation of the oscillating ellipsoid liquid drop and the spherical liquid drop rainbow image in a stable state; converting the ellipsoid degree information of the liquid drops into oscillation amplitude information, and fitting by using a damping oscillation function; and obtaining the oscillation frequency and the time constant of the damping oscillation function by fitting, and respectively obtaining the surface tension and viscosity value of the liquid.
Further, the method for calibrating the rainbow signal height and the scattering angle in the step (3) comprises the following steps:
the method comprises the steps of arranging a reflector with a rotary displacement table in a liquid drop measuring area in the extension direction of a main optical axis of a laser beam expanding unit, adjusting the rotary displacement table, enabling light rays reflected by the reflector to coincide with the main optical axis of an optical system unit, recording an initial angle of the rotary displacement table, finely adjusting a rotation angle of the rotary displacement table, recording positions of a rotation angle and reflected light on a digital camera, combining angles of a laser beam emitted by a laser in the liquid drop generating unit and the main optical axis of the optical system unit to obtain a scattering angle of a calibration point, and further obtaining a relation between a pixel and a scattering angle of a digital camera in a signal processing and collecting unit. And (3) adjusting the vertical heights of the reflector and the laser synchronously, measuring the variation of the heights, and repeating the measuring process to obtain the corresponding relation between the measuring points with different heights on the one-dimensional line and the upward and downward directions of the pixels of the digital camera.
Further, the angular deviation of an ellipsoidal droplet is related to the ellipticity of the droplet by
Calculating by the formula:
wherein, thetagn，θrgThe geometrical rainbow angles of the ellipsoidal liquid drop and the spherical liquid drop with the same volume respectively; xi is the ellipsoid degree of the ellipsoid liquid drop; beta, thetargAre obtained by the following formulas:
where m is the refractive index of the droplet.
Further, the polar radius of the droplet may be represented by the following formula:
wherein r is0The radius of a spherical liquid drop with the same volume; theta is the polar angle of the ellipsoid; a (t) is a function of the amplitude of oscillation of the liquid drop along with time, and the relationship between the amplitude and the ellipticity of the liquid drop can be expressed as:
and fitted by the following formula:
A(t)＝A0exp(-t/τ)·sin[Ω·t+φ]+c (6)
wherein A is0Phi is the amplitude and phase of the liquid drop oscillation at 0 moment; tau and omega are time constant and frequency of oscillation; c is the offset of the asymmetric oscillation.
Based on the description of Rayleigh and Lamb on free oscillation of liquid drops, the time constant and frequency of oscillation are respectively related to the viscosity mu and the surface tension sigma of the liquid, and under a second-order oscillation mode, the method is determined by the following formula:
wherein Ω is represented by formula
Correction, ρ is the liquid density, r0Is the radius of the droplet at steady state.
The invention also provides a device for simultaneously measuring the surface tension and the viscosity of the liquid on line, which comprises a liquid drop generating unit, a sheet laser beam expanding unit and a signal acquisition and processing unit;
the liquid drop generating unit comprises a liquid drop generator, an injection pump and a piezoelectric driver, wherein the injection pump sends the liquid to be detected into the liquid drop generator and then generates oscillation liquid drops of the liquid to be detected under the action of the piezoelectric driver;
the chip laser beam expanding unit comprises a laser, a beam expanding element and a reflector, wherein a laser beam emitted by the laser is modulated into chip laser through the beam expanding element, and the chip laser irradiates oscillating liquid drops through the reflector to generate a rainbow signal;
and the signal acquisition and processing unit comprises a digital camera and a field lens, and is used for imaging rainbow signals of the oscillating liquid drops with different heights on different pixel lines of the digital camera through optical filtering respectively and outputting the rainbow signals in a data form.
Further, the drop generator may be a monodisperse drop generator or a single drop generator, respectively, for generating an oscillating stream of drops and a single drop.
The laser is a continuous laser and is used for generating laser beams with adjustable intensity, the beam expanding element expands the emitted laser beams into sheet lasers, and the reflector is arranged on the rotating table and is used for reflecting the sheet lasers to the liquid drops and the motion tracks of the liquid drops.
The reflector is arranged on the rotary displacement table.
The beam expanding element is a beam expander or a lens group.
The signal acquisition and processing unit comprises a field lens, a horizontal slit diaphragm and an area array digital camera; scattered light emitted from the liquid drops sequentially passes through the field lens and the horizontal slit diaphragm and then enters the area-array digital camera. Wherein, the visual field lens is convex lens, and convex lens, horizontal slit diaphragm and digital camera set gradually in the rainbow angle region of liquid drop and collineation. And, a horizontal slit diaphragm is disposed on a back focal plane of the convex lens.
Rainbow signals scattered by the liquid drops at different heights are collected by the field lens, and the horizontal slit diaphragm positioned on the focal plane of the field lens enables only the rainbow signals horizontally entering the field lens to pass through, so that the rainbow signals of the liquid drops at different heights are separated; controlling the size of a field area by adjusting the distance between a digital camera and a horizontal slit diaphragm; the height of the liquid drop generating unit is adjusted, so that the digital camera records a rainbow image of liquid drops oscillating to form a stable sphere.
The horizontal slit diaphragm is adjustable in width, the line width is 0.5 mm-5 mm, and the horizontal slit diaphragm is located on the back focal plane of the field lens.
The signal acquisition and processing unit comprises a field lens and a linear array digital camera, and scattered light emitted from the liquid drops enters the linear array digital camera through the field lens.
Furthermore, the device provided by the invention also comprises a linear moving and rotating device. The monodisperse droplet flow generator or the single droplet generator is arranged on a displacement platform with five degrees of freedom and is used for adjusting the position and the collimation of the droplet track; and the digital camera is arranged on the linear displacement table and used for controlling the liquid drop height corresponding to the collected scattering signals.
The invention has the advantages that: the surface tension and the viscosity of the liquid drop are measured in a non-contact type online manner, so that the sample is not polluted; the rainbow angle of the droplets is very sensitive to their ellipsoids, so that small deformations can be detected and resolved by the digital camera; the position information of the liquid drop is converted into the time information of the liquid drop oscillation deformation, and the time resolution of the system is greatly improved.
The method and the device for simultaneously measuring the surface tension and the viscosity of the liquid realize the simultaneous online measurement of the surface tension and the viscosity of the liquid; the method has the characteristics of simple and convenient operation, short time consumption, suitability for liquid parameter measurement under extreme conditions of supercooling, overheating and the like; the transient surface tension and viscosity of the liquid drop forming process can be determined quickly, accurately and effectively.
Drawings
FIG. 1 is a schematic structural diagram of a device for simultaneously measuring surface tension and viscosity of a liquid on line according to the present invention;
FIG. 2 is a schematic structural diagram of another device for simultaneously measuring the surface tension and viscosity of a liquid in an online manner according to the present invention;
wherein, 1, a laser; 2. a beam expanding element; 3. a mirror; 4. a field lens; 5. a horizontal slit diaphragm; 6. an area-array digital camera; 7. a monodisperse droplet flow generator; 8. an injection pump; 9. a piezoelectric driver; 10. a stream of droplets; 11. a linear array digital camera; 12. a single drop generator; 13. single drops and their motion trajectory;
fig. 3 is a rainbow image recorded by the area-array digital camera provided in example 1;
FIG. 4 shows the fitting results of the rainbow image oscillations in example 1.
Detailed Description
The following further describes embodiments of the present invention by way of examples, in conjunction with the accompanying drawings.
Example 1
As shown in fig. 1, a schematic structural diagram of a device for simultaneously measuring surface tension and viscosity of a liquid on line provided by the present invention includes a droplet generation unit, a sheet laser beam expansion unit, and a signal acquisition and processing unit. Wherein the droplet generation unit comprises a monodisperse droplet generator 7, a syringe pump 8 and a piezoelectric actuator 9 for generating a steady stream of monodisperse droplets 10; the sheet laser beam expanding unit comprises a laser 1, a beam expanding element 2 and a reflector 3, and is used for generating a sheet light source and irradiating a liquid drop stream; the signal acquisition and processing unit comprises a field lens 4, a horizontal slit diaphragm 5 and an area array digital camera 6. And the chip laser beam expanding unit and the signal acquisition and processing unit are respectively positioned on the two linear guide rails.
Specifically, in the present embodiment: the laser 1 adopts a semiconductor continuous laser with the wavelength of 532 nanometers; the beam expanding element 2 is a 20-time beam expander and expands 2 mm laser into 40 mm; the diameter of the field lens 4 is 100 mm, and the focal length is 150 mm; the slit width of the horizontal slit diaphragm 5 is 1 mm; the pixel size of the area array digital camera is 5.86 micrometers, the number of pixels is 1200 multiplied by 1920, and the height of an effective measuring area is 11.5 centimeters. The method for measuring the surface tension and the viscosity of the liquid by using the device comprises the following steps:
step 1: turning on the droplet generation unit: the injection pump 8 and the monodisperse droplet flow generator 7 are connected by a hose, and the piezoelectric driver 9 is connected to the positive and negative electrodes of the piezoelectric ceramic plate of the monodisperse droplet flow generator 7 by a lead. After the connection is finished, the injection pump 8 pushes the liquid to be detected into the monodisperse droplet flow generator 7, and parameters such as the flow rate of the injection pump 8 and the excitation frequency of the piezoelectric driver 9 are adjusted, so that the jet flow crushing process of the monodisperse droplet flow generator 7 is under a Rayleigh mechanism to generate a monodisperse droplet flow 10 with second-order oscillation (second-order mode);
step 2: and starting the laser 1, expanding the laser beam into sheet laser after passing through the beam expanding element 2, and adjusting the angle and the position of the reflector 3 to enable the sheet laser to irradiate the droplet flow 10.
And step 3: adjusting the position and the angle of the signal processing and collecting unit to enable the signal processing and collecting unit to be positioned near a rainbow area of the liquid drop; simultaneously, adjusting the distance between the area array digital camera 6 and the horizontal slit diaphragm 5, and controlling the size of the recorded field of view; the height of the monodisperse droplet stream generator 7 is adjusted so that the area-array digital camera 6 records the rainbow image of the oscillation of the stream of monodisperse droplets 10 from the droplets to a stable spherical shape, as shown in figure 3.
And 4, step 4: after the recording is finished, calibrating the rainbow signal height and the scattering angle by using the sheet laser beam expanding unit, the reflecting mirror and the rack system to obtain a calibration curve of the pixel array and the scattering angle; the method specifically comprises the following steps:
a reflector with a rotary displacement table is arranged in a liquid drop measuring area in the extension direction of a main optical axis of the chip laser beam expanding unit; adjusting the rotary displacement table to enable light rays reflected by the reflector to coincide with a main optical axis of the laser beam expanding unit, and recording an initial angle of the rotary displacement table; finely adjusting the rotation angle of the rotary displacement table, recording the rotation angle and the position of reflected light on the digital camera, and combining the recorded initial angle of the displacement table to obtain the scattering angle of the calibration point so as to obtain the relationship between the digital camera pixel and the scattering angle in the signal processing and collecting unit;
the vertical heights of the reflector and the laser beam expanding unit are synchronously adjusted, the position of the light beam on the digital camera is recorded, and the corresponding relation between the measuring points with different heights on the one-dimensional line and the upward and downward directions of the pixels of the digital camera can be obtained.
And 5: extracting signals of every 40 pixel rows in the recorded rainbow image, corresponding the signals to a calibration curve, and inverting the rainbow image in a steady state to obtain the refractive index m and the radius r of the spherical liquid drop0。
Step 6: and (4) rapidly analyzing the surface tension and viscosity information of the liquid by using a processing program. The treatment process comprises the following steps: firstly, calculating the angular deviation delta theta of the oscillating liquid drop and a liquid drop rainbow image in a steady state, and calculating the evolution of the ellipsoid degree of the liquid drop by using a formula (1); converting the ellipticity of the liquid drop into oscillation amplitude information by using a formula (5), and fitting the oscillation amplitude information by using a formula (6); and (3) obtaining the oscillation frequency and the time constant of the damping oscillation function by fitting, and obtaining the surface tension and viscosity value of the liquid by respectively using a formula (7) and a formula (8).
As shown in FIG. 4, the oscillation frequency and time constant of an ethanol droplet with a temperature of 20.3 ℃ and a steady state radius of 71.5 μm were measured to be 24840 Hz and 0.672 ms, respectively, and the corresponding surface tension and viscosity values were 73.72mN/m and 1.09 mPas, respectively.
Example 2
As shown in fig. 2, another device for simultaneously measuring the surface tension and the viscosity of a liquid on line provided by the present invention includes a droplet generation unit, a laser beam expansion unit and a signal acquisition and processing unit. The liquid drop generating unit comprises a single liquid drop generator 12, an injection pump 8 and a piezoelectric driver 9, and is used for generating an oscillating single liquid drop 13; the sheet laser beam expanding unit comprises a laser 1, a beam expanding element 2 and a reflector 3, and is used for generating a sheet light source and irradiating liquid drops and the motion trail of the liquid drops; the signal acquisition and processing unit comprises a field lens 4 and a linear array digital camera 11. The method for measuring the surface tension and the viscosity of the liquid by using the device comprises the following steps:
step 1: turning on the droplet generation unit: the syringe pump 8 and the single droplet generator 12 are connected by a hose, and the piezoelectric driver 9 is connected to the positive and negative electrodes of the piezoelectric ceramic sheet of the single droplet generator 12 by a lead. After the connection is finished, the injection pump 8 pushes the liquid to be measured into the single droplet generator 12, and parameters such as the flow rate of the injection pump 8 and the excitation frequency of the piezoelectric driver 9 are adjusted, so that the single droplet generator 12 generates single droplets 13 with second-order oscillation at certain time intervals.
Step 2: starting the laser 1, expanding the laser beam into a piece of laser after passing through the beam expanding element 2, and adjusting the angle and the position of the reflector 3 to enable the piece of laser to irradiate the liquid drop 13 and the motion track thereof;
and step 3: adjusting the position and the angle of the signal processing and collecting unit to enable the signal processing and collecting unit to be positioned near a rainbow area of the liquid drop; controlling the linear array digital camera 11 to record a rainbow image of the single liquid drop 13 liquid drop oscillation;
the liquid surface tension and viscosity simultaneous on-line measuring device of the embodiment is used for calibrating the rainbow signal height and angle, and the data processing method is as in embodiment 1.
The above detailed description is provided for the device for simultaneously measuring the surface tension and the viscosity of a liquid on line, and the description of the embodiment is only for the purpose of assisting understanding of the method of the present invention and should not be construed as limiting the present invention.
Claims (10)
1. A method for simultaneously measuring the surface tension and the viscosity of a liquid on line is characterized by comprising the following steps:
(1) the liquid drop generating unit generates liquid drops oscillating in a second-order mode, and the cross section of each liquid drop is ellipsoidal;
(2) the chip laser beam expanding unit generates chip laser and irradiates the oscillated liquid drop and the motion trail thereof to generate a rainbow signal; the signal processing and collecting unit records the oscillating ellipsoid liquid drop to form a rainbow image of the spherical liquid drop in a stable state;
(3) calibrating the rainbow signal height and the scattering angle in the rainbow image to obtain a calibration curve of a pixel column and the scattering angle; extracting signals in the rainbow image, corresponding to the calibration curve, and inverting the rainbow image in a steady state to obtain the refractive index and the radius of the spherical liquid drop;
(4) combining the refractive index and the radius of the spherical liquid drop, and obtaining the evolution condition of the ellipsoid degree in the liquid drop falling process according to the rainbow angle deviation of the oscillating ellipsoid liquid drop and the spherical liquid drop rainbow image in a stable state; converting the ellipsoid degree information of the liquid drops into oscillation amplitude information, and fitting by using a damping oscillation function; and obtaining the oscillation frequency and the time constant of the damping oscillation function by fitting, and respectively obtaining the surface tension and viscosity value of the liquid.
2. The method for on-line measurement of liquid surface tension and viscosity simultaneously as claimed in claim 1, wherein the method for calibrating rainbow signal height and scattering angle in step (3) comprises:
a reflector with a rotary displacement table is arranged in a liquid drop measuring area in the extension direction of a main optical axis of a sheet laser beam expanding unit, the rotary displacement table is adjusted, light rays reflected by the reflector are overlapped with the main optical axis of an optical system unit, the initial angle of the rotary displacement table is recorded, the rotation angle of the rotary displacement table is finely adjusted, the positions of a rotation angle and reflected light on a digital camera are recorded, and the scattering angle of a calibration point can be obtained by combining the angle between a laser beam emitted by a laser in a liquid drop generating unit and the main optical axis of the optical system unit, so that the relation between the pixel of the digital camera in a signal processing and collecting unit and the scattering angle is obtained;
and (3) adjusting the vertical heights of the reflector and the laser synchronously, measuring the variation of the heights, and repeating the measuring process to obtain the corresponding relation between the measuring points with different heights on the one-dimensional line and the upward and downward directions of the pixels of the digital camera.
3. The method for the simultaneous on-line measurement of liquid surface tension and viscosity according to claim 1, characterized in that the drop oscillation process in step (4) is fitted by the following formula:
A2(t)＝A0exp(-t/τ)·sin[Ω·t+φ]+c
wherein A is0Phi is the amplitude and phase of the liquid drop oscillation at 0 moment; tau and omega are time constant and frequency of oscillation; c is the offset of the asymmetric oscillation.
4. The method for on-line measurement of liquid surface tension and viscosity simultaneously as claimed in claim 1, wherein in step (4), the liquid viscosity μ and the surface tension σ are obtained by calculating the time constant and frequency of oscillation respectively according to the following formula:
wherein Ω is represented by formula
Correction, ρ is the liquid density, r0Is the radius of the droplet at steady state.
5. A device for simultaneously measuring the surface tension and the viscosity of a liquid on line is characterized by comprising a liquid drop generating unit, a sheet laser beam expanding unit and a signal acquisition and processing unit;
the liquid drop generating unit comprises a liquid drop generator, an injection pump and a piezoelectric driver and is used for generating oscillation liquid drops of the liquid to be detected;
the chip laser beam expanding unit comprises a laser, a beam expanding element and a reflector, wherein a laser beam emitted by the laser is modulated into chip laser through the beam expanding element, and the chip laser irradiates oscillating liquid drops through the reflector to generate a rainbow signal;
and the signal acquisition and processing unit comprises a digital camera and a field lens, and is used for imaging rainbow signals of the oscillating liquid drops with different heights on different pixel lines of the digital camera through optical filtering respectively and outputting the rainbow signals in a data form.
6. The device for the simultaneous on-line measurement of liquid surface tension and viscosity according to claim 5, wherein the mirror is mounted on a rotary displacement table.
7. The device for on-line measurement of liquid surface tension and viscosity simultaneously according to claim 5, wherein the beam expanding element is a beam expander or a lens group.
8. The device for the simultaneous on-line measurement of the surface tension and the viscosity of a liquid according to claim 5, wherein the signal acquisition and processing unit comprises a field lens, a horizontal slit diaphragm and an area array digital camera; scattered light emitted from the droplet flow sequentially passes through the field lens and the horizontal slit diaphragm and then enters the area-array digital camera.
9. The device for the simultaneous on-line measurement of the surface tension and the viscosity of a liquid according to claim 8, wherein the horizontal slit diaphragm has an adjustable width, a line width of 0.5mm to 5mm, and is located in a back focal plane of the field lens.
10. The device for the simultaneous on-line measurement of the surface tension and viscosity of a liquid according to claim 5, wherein the signal acquisition and processing unit comprises a field lens and a line digital camera, and wherein scattered light emitted from the liquid drop enters the line digital camera through the field lens.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112611680A (en) * | 2021-01-14 | 2021-04-06 | 新疆大学 | Liquid viscosity detection device |
| CN112666047A (en) * | 2021-01-14 | 2021-04-16 | 新疆大学 | Liquid viscosity detection method |
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| CN112611680A (en) * | 2021-01-14 | 2021-04-06 | 新疆大学 | Liquid viscosity detection device |
| CN112666047A (en) * | 2021-01-14 | 2021-04-16 | 新疆大学 | Liquid viscosity detection method |
| CN113029872A (en) * | 2021-03-25 | 2021-06-25 | 兰州理工大学 | Method and system for measuring surface tension of liquid metal of welding pool in real time |
| CN113281221A (en) * | 2021-05-19 | 2021-08-20 | 太原理工大学 | Method and system for measuring viscosity and surface tension of high-temperature molten mass |
| CN113281221B (en) * | 2021-05-19 | 2023-07-25 | 太原理工大学 | Method and system for measuring viscosity and surface tension of high-temperature melt |
| CN114324071A (en) * | 2021-12-31 | 2022-04-12 | 四川大学 | Method for measuring surface tension coefficient of liquid by breaking liquid drops |
| CN114324072A (en) * | 2022-01-17 | 2022-04-12 | 四川大学 | Method for measuring surface tension coefficient of liquid by thin plate method |
| CN114749222A (en) * | 2022-03-30 | 2022-07-15 | 北京航空航天大学 | Integrated piezoelectric multi-column uniform liquid drop generator |
| CN114749222B (en) * | 2022-03-30 | 2023-05-05 | 北京航空航天大学 | Integrated piezoelectric type multi-column uniform liquid drop generator |
| CN117606980A (en) * | 2023-09-22 | 2024-02-27 | 中煤科工开采研究院有限公司 | Method for measuring the flow properties of a liquid and device for observing liquid drops |
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