Elastic Diaphragm Research Articles

Fiber Bragg grating guided laser interferometer-based highly sensitive vacuum pressure sensor

Vacuum sensing and metrology pave the way for promising solutions to fulfill the scientific and technological demands of various contemporary industries and research fields. This study introduces an innovative vacuum pressure sensor, employing a fiber Bragg grating (FBG) guided Michelson interferometer. The sensor works on the principle of interferometric measurement of precisely gauging the displacement of an elastic diaphragm with pressure variation connected to a vacuum chamber in terms of interference fringe counts due to arm-length variation of the interferometer. The elastic silicone diaphragm and stainless steel cantilever, being critical components of the sensor, were examined using finite element analysis and subsequently demonstrated experimentally. The diaphragm’s position is continuously monitored in real time through the Bragg’s wavelength of the FBG, continuously updating the interferometer after each 15 ms for the accurate measurement of fluctuating vacuum pressures. The strain-induced shift in the FBG’s Bragg wavelength follows a linear trend with pressure variation, exhibiting a sensitivity of 12.7 pm/mbar. With a dynamic range spanning 0.05–100 mbar, the sensor demonstrates a sensitivity of 16.073 fringe counts/mbar and a notable resolution of 0.3364 mbar. Moreover, the sensor exhibits good repeatability, with a hysteresis of up to 2.59% during full span cyclic operation. The coupling of the interferometer with FBG makes it a unique secondary standard solution for precision vacuum measurement.

Development of Elastic Diaphragm Structure for Ultralow Stiffness Probe and Mechanical Properties Testing Method

Development of Elastic Diaphragm Structure for Ultralow Stiffness Probe and Mechanical Properties Testing Method

Experimental Investigations on the Wake‐Induced Vibration of an Electromagnetic Energy‐Harvesting System

The wake energy of an electromagnetic harvesting device is derived from the phenomena of wake‐induced vibration (WIV). Experiments were conducted to determine the effects of the Reynolds number, the resistance of the circuit, and the distance between two concentric circular cylinders on the wake energy of the flow. The mechanism of the diaphragm energy harvester (DEH) consists of a single and tandem circular cylinders, which were examined separately. An elastic diaphragm with a magnet was also mounted in the wake of the cylinders. The Reynolds number varies between 2000 and 5000. The converter transforms the wake energy of the flow into electricity due to the vibration of the cylinder in a magnetic field. This research fills a critical gap in the literature by investigating the energy performance of a DEH under the wake‐induced vibration of two fixed circular bluff bodies, demonstrating for the first time the feasibility of capturing vortex energy through the wake in the presence of a diaphragm. This unique approach distinguishes our work in the field of electromagnetic energy‐harvesting devices, showcasing the potential for practical applications in renewable energy generation. The test results indicate that increasing the Reynolds number enhances the converter’s power output. Additionally, it has been observed that two critical distances are significant for the output voltage: the gap between the tandem cylinders (L∗) and the distance between the edge of the diaphragm and the center of the cylinder (X∗). The voltage output of tandem cylinders suggests that an optimal cylinder spacing falls within the range of 4 ≤ L∗ < 5.

Dynamic Low-Pressure Measurement Using a Fiber Optic-based Fabry-Perot Interferometer

A dynamic low-pressure measurement using a fiber optic-based Fabry-Perot Interferometer (FFPI) has been demonstrated in this work. The developed system has been divided into 2 main parts: pressure source and sensing system. The former is a chamber comprised of an elastic diaphragm, which proportionally deflects according to input pressure from an air pump. The FFPI, consequently, detects the material deflection and demodulates the parameter into useful pressure value via the fringe counting technique and Kirchhoff-Love’s plate theory. To validate the performance of the developed system, a reference pressure instrument is utilized while the air pump feeds pressure of 0.34–6.57 mbar with 10 times repeatability into the system. The experimental results indicated that the FFPI can measure the pressure of 0.343–6.568 mbar, while the reference instrument showed the output values from 0.343–6.471 mbar, respectively. Moreover, the average and maximum percentage error in measurement is 1.27% and 2.67%, respectively. The resolution of the FFPI sensor is also analyzed to be approximately 0.05% or 0.0382 mbar/μm over all measurement ranges. Therefore, we conclude that the FFPI has high accuracy, resolution, linearity, and reliability in dynamic low-pressure measurements.

A Simplified Method for Evaluating the Diaphragm Flexibility for Frame-Shear Wall Structure under Earthquake Load

The rigid floor assumption is commonly used in structural design, but it is not applicable to buildings with a large plane aspect ratio. This study designed nine frame-shear wall structures with the story of 3, 6, and 12, with a plane aspect ratio of 2, 3.33, and 4. Based on the design results, the finite element models were set up by ETABS. Both the rigid diaphragm and the flexible diaphragm cases were considered in each model. The effect of elastic diaphragm deformation on structural seismic performance was investigated, including fundamental period, top displacement, inter-story drift, and base shear force. The results indicate that the diaphragm deformation on 3-story structures is more significant than that on 6-story and 12-story structures. The diaphragm in-plane deformation increases with the aspect ratio. On the basis of the analysis results, a simplified formula to calculate the internal force amplification factor and a quantitative assessment method for evaluating the diaphragm flexibility were proposed, which can provide a reference for engineering design.

Impact of Elastic Diaphragm Hardness and Structural Parameters on the Hydraulic Performance of Automatic Flushing Valve

Automatic flushing valve (AFV) can improve the anti-clogging ability of the drip fertigation system. The minimum inlet pressure (Hamin) required for automatic closing and the maximum flushing duration (FDmax) are two important performance indexes of AFV. The existing AFV products have the problem of larger Hamin and smaller FDmax, which result higher investment and operating cost, and poor flushing efficiency. Based on the mechanical analysis of the AFV elastic diaphragm and the derivation of the FD, elastic diaphragm hardness (E), ascending channel offset distance (D), and drain hole width (W) were selected as the experimental factors, and nine AFVs were designed by L9(33) orthogonal test method to investigate the influence of elastic diaphragm hardness and structural parameters on the hydraulic performance of AFVs. The hydraulic performance test results showed that the Hamin of the nine AFVs ranged from 0.026 to 0.082 MPa and FDmax ranged from 36.3 to 95.7 s. Hamin was positively correlated with E and D and negatively correlated with W. FDmax was negatively correlated with E and W and tended to increase and then decrease with D. All elastic diaphragm hardness and structural parameters had a significant effect on Hamin, and E and W had a significant effect on FDmax. Based on the range analysis, two new combinations of AFV elastic diaphragm hardness and structural parameters with minimum Hamin (E = 40 HA, D = 0 mm, W = 2 mm) and maximum FDmax (E = 40 HA, D = 2 mm, W = 1.68 mm) were determined, and the corresponding Hamin was 0.022 MPa, 63.3% lower than that of the existing product, and FDmax was 116.4 s, 71.2% higher than that of the existing product. In this study, two ternary nonlinear mathematical regression models of Hamin and FDmax with elastic diaphragm hardness and structural parameters was constructed. The simulation accuracy of the models is good and can be used to quickly predict the optimal combination of AFV parameters to satisfy the actual engineering-required Hamin and FDmax.

Highly accurate differential pressure FBG gas flow sensor

In this paper, the limitations of traditional electronic-type gas flow sensors for flow measurements in practical engineering applications such as flammable and explosive gas environments are discussed. Further, the importance and uncertainty of gas flow measurements in critical parts of industrial equipment are also discussed. In this work, a high-precision differential-pressure FBG gas flow and a temperature sensor with an embedded nozzle were designed using a long-diameter nozzle-type throttle tube with a fiber optic Bragg grating and an elastic-sensitive diaphragm composite strain mechanism. It was observed that the pressure difference between the two sides of the nozzle leads to the deformation of the elastic-sensitive diaphragm, and it results in a wavelength drift of the strain grating that is attached to the elastic diaphragm. Further, it also enables real-time monitoring of the gas flow value. Moreover, the temperature compensation grating which was attached to the side wall of the gas chamber was used to eliminate the cross-sensitivity of the strain grating as well as to improve measurement accuracy while implementing a temperature monitoring system. The experimental results showed that the Bragg wavelength drift in the fiber grating gas flow sensor acts as a quadratic curve with respect to the gas flow, and the experimental results were found to be highly compatible with the results of the theoretical analysis.

Multi-factorial failure of pressure-compensating emitters in drip fertigation systems: An in-situ sampling investigation

Pressure-compensating emitter (PCE) is an important equipment to improve irrigation and fertigation uniformity of drip irrigation system. Due to multiple factors, PCE failure would lead to the whole drip irrigation system failure and consequently affect the crop growth. However, few studies reported the key reason and influential factors of PCE failure yet. Therefore, an in-situ sampling study of PCE, which was collected from 16 different operating locations and all were operated for several years in the apple orchard, was conducted in this paper. The effects of water quality characteristics and climatic conditions on the fouling formation inside PCE and the mechanical properties of the elastic diaphragm were analyzed. The result indicated that the PCE relative average discharge (Dra) decreased by 4.65%− 33.19% after 3–9 years. The phosphorus content, average temperature, suspended particles, and pH showed significant impacts on fouling accumulation inside the PCE flow channel, particularly biofouling. Meanwhile, the stretch rate, elastic modulus, tensile strength, and the hardness of PCE elastic diaphragm were mainly affected by humidity conditions, longitude, SO42- content and pH. Both the fouling accumulation and elastic diaphragm variations synthetically decreased the Dra of the drip irrigation system. This study provides theoretical support to further improve the irrigation uniformity of drip irrigation systems.

A Wide Range and High Repeatability MEMS Pressure Sensor Based on Graphene

Graphene pressure sensors have attracted extensive attention due to their excellent performance. However, the range and linearity of conventional suspension graphene pressure sensors are too small to meet commercial requirements. In this article, we propose a wide range and high repeatability MEMS pressure sensor based on graphene array structure. Single-layer chemical vapor deposition (CVD) graphene was transferred at the root of silicon pressure-bearing elastic diaphragm, and it was simultaneously protected by the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanofilm. In addition, the Au/Sn eutectic bonding technology was employed to complete the hermetic package of the sensor. Pressure tests showed that the repeatability error of the pressure sensor in the range of 0–20 MPa was 4.062% full scale output (FSO) and the hysteresis was 2.118% FSO. Furthermore, the temperature resistance studies confirmed that the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanofilm can effectively protect graphene due to its extremely high thermal stability. And with excellent characteristics of high long-term stability, it can work stably in humid environments. Conclusionally, this research provides significant exploration to promote the practicality and commercialization of graphene devices.

High sensitivity fiber optic acceleration sensor based on Fabry-Perot interferometer

• This paper proposes a high sensitivity fiber optic acceleration sensor based on Fabry-Perot interference. • The sensitivity of the sensor is 3.81 nm/g at 300 Hz, and the resonance frequency of the sensor is 800 Hz. • The sensor has a simple structure, low cost and easy to fabricate. A high sensitivity fiber optic acceleration sensor based on Fabry-Perot interferometer is proposed and experimentally demonstrated. The proposed sensor is composed of a sensor pedestal, a mass block, elastic diaphragm and two reflectors, wherein the collimating reflector 1 and the reflector 2 constitute a fiber Fabry-Perot (F-P) interference cavity. By analyzing the relevant parameters of F-P interference theory, we modulate the F-P reflection spectrum with high finesse, and demodulate the F-P reflection spectrum by wavelength demodulation method to obtain the acceleration signal. Through simulation analysis and experimental verification, the resonant frequency, sensitivity and lateral anti-interference ability of the sensor have been investigated. The experimental results show that the resonant frequency of the sensor is 800 Hz, the sensitivity is 3.81 nm/g when the frequency is 300 Hz, the resolution is 0.263 mg, and the lateral anti-interference degree is less than 5 %. Furthermore, the proposed acceleration sensor exhibits the advantages of simple structure and low cost, and has great application prospects in the vibration monitoring of the pitch bearing of wind power generation.

Abundant exact solutions for the deoxyribonucleic acid (DNA) model

In this study, the improved [Formula: see text] expansion method and Exp[Formula: see text] function method are used to construct the newly closed-form exact solutions for the deoxyribonucleic acid (DNA) model which includes hyperbolic, trigonometric and exponential solutions. These solutions include a wealth of information regarding the dynamical behavior of homogeneous long elastic rods with circular cross-sections. These rods comprise a pair of polynucleotide rods of the DNA molecule that are connected by an elastic diaphragm, demonstrating the involvement of the hydrogen bond in this communication. The performance of these approaches demonstrates their use and efficacy in solving a variety of nonlinear evolution problems of integer and fractional order. The physical significance of the established and the obtained solutions has been shown via 3D shapes. It is worth noting that the solutions obtained here via the proposed schemes are more generalized and can be helpful to demonstrate the internal interaction of the DNA model arising in mathematical biology. The proposed method has been used to obtain exact traveling wave solutions for fraction nonlinear partial differential equations (NPDEs) arising in nonlinear sciences.

Design of a Fiber Bragg Grating Pressure Sensor Based on a Metal Diaphragm and Lever Structure.

In this paper, a pressure sensor based on a metal diaphragm and lever structure is designed, the sensing principle and mechanical structure of this sensor are analyzed and simulated, and its sensitization effectiveness and temperature compensation are verified. The maximum deflections of metal diaphragms of different sizes and materials were compared, and it was found that the square beryllium bronze diaphragm with a thickness of 1 mm and a side length of 20 mm had good elastic properties. The influence of the FBG in different positions of the lever on the center wavelength is analyzed. The sensitivity of the bare FBG is markedly improved under the influence of the two structures of the square elastic diaphragm and the lever, with a typical pressure sensitivity of 3.35 nm/MPa at 3 mm to the left of the lever center. The purpose of temperature compensation is achieved by adding another FBG that measures the temperature, and the sensing sensitivity can be tuned by adjusting the position of the FBG. It can meet the detection needs of a small range and high sensitivity.

Simultaneous Measurement of Temperature and Pressure Based on Ring-Shaped Sensing Structure With Polymer Coated No-Core Fiber

A ring-shaped structure based on polymer coated no-core fiber (NCF) is presented for simultaneous temperature and pressure measurements. The sensing structure is fabricated by splicing the partially coated NCF between single-mode fibers and bending it into a loop. The anti-resonance effect is formed in the NCF and the resonant dips have wavelength shift responses to the temperature and displacement variations. It should be noted that the increase of temperature leads to a decrease in the polymer coating refractive index and changes the displacement measurement sensitivity, thus, the compensation algorithm is required to resolve this cross-sensitivity problem. Combining the ring-shaped structure with the elastic diaphragm encapsulation can convert seawater pressure into structural deformation displacement to achieve pressure measurement. The experimental and simulation results show that this sensor offers a high temperature sensitivity of −5.098 nm/°C with the resolution of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 10^{-4}$ </tex-math></inline-formula> °C and a pressure sensitivity of −2.368 nm/MPa with the resolution of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.4\times 10^{-3}$ </tex-math></inline-formula> MPa. In addition, the sensing performances could be changed by adjusting the NCF size and the ring-shaped structure diameter, which enables this sensing structure to have a broader application potential for seawater parameter measurement.

Structure design and optimization of SOI high-temperature pressure sensor chip

A high-temperature pressure sensor chip based on SOI(Silicon-On-Insulator) material is designed in this paper. In this paper, the structural design of the elastic pressure-sensitive diaphragm is carried out, and the diaphragm dimensions are optimized using finite element analysis, according to the sensor's Wheatstone bridge principle and hydrostatic simulation method, combined with the sensor's design requirements. The optimal design dimensions of the elastic pressure-sensitive diaphragm at 2.1 MPa pressure were finally determined, with an island width w1 of 600 μm, a membrane length of w2 of 1000 μm, a membrane thickness h1 of 60 μm, and an island height h2 of 440 μm. Under the premise of 5KΩ varistor value, the packaging structure and process of the sensor are designed to finally obtain the test results that meet the initial setting value.

Flow characteristics and diaphragm deformation of pressure‐compensating drip irrigation emitters*

AbstractPressure‐compensating (PC) emitters are extensively utilized because they can enhance the irrigation uniformity and the terrain adaptability of drip irrigation systems. To examine the interaction between the elastic diaphragm and fluid of PC emitters, the internal flow behaviour and the diaphragm deformation of PC emitters were studied by one‐way and two‐way fluid–structure interaction (FSI) numerical simulation methods. The deformation characteristics of the elastic diaphragm, the change of the outflow section around the outlet of the pressure‐compensating chamber, and the pressure and velocity distribution of the flow field were analysed in this study. The results illustrate that the deformation process of an elastic diaphragm during the entire working process could be divided into three phases: rapid deformation, slow deformation, and long‐term tiny deformation. After the diaphragm contacted convex land, the overflow groove was the only channel where water could flow out of the PC emitters; and as working pressure increased, the increment of the diaphragm deformation was extremely tiny. However, it was the tiny deformation of the elastic diaphragm that maintained the flow rate of the PC emitters constant over a wide range of working pressures. The results can provide references for exploring the pressure‐compensating mechanism of PC emitters and their optimal design.

Layout Design of a Press Compactor for Compacting Moisture-Containing Industrial Waste and Analysis of the Water Separation Process in the Area of the Screw Drive

The article presents a design and technological scheme of the layout of a press compactor for moisturecontaining industrial waste with a conical screw drive and an additional compacting unit in the form of a multi-petal elastic diaphragm. A model for separating the liquid fraction from the waste being compacted through a perforated conical insert surrounding the screw has been developed.

High-precision optical fiber pressure sensor using frequency-modulated continuous-wave laser interference

This work presents a high-precision fiber optic pressure sensor based on frequency-modulated continuous-wave (FMCW) laser interference. The pressure sensor is primarily composed of a diaphragm-type Fabry–Pérot (F–P) cavity, with the diaphragm fabricated using high-elasticity SUS631 stainless steel. The external air pressure causes the center of the elastic diaphragm to deform, and this deformation results in a change in the F–P cavity length. The FMCW laser-interference method was used to demodulate the change in the length of the cavity and realize high-precision pressure measurements. The experimental results showed that when the pressure measurement is in the range of 0 kPa–600 kPa, an accuracy of 3.8 Pa can be obtained. In addition, the sensor had very good linearity with pressure change (R2 = 0.999 94), repeatability, and stability.

Influence of Constraint Method of Elastic Diaphragm on Numerical Simulation of Pressure-Compensating Emitter

HighlightsDeformation of the elastic diaphragm can affect the flow field characteristics of a pressure-compensating emitter.The contact constraint method’s simulation of the elastic diaphragm were consistent with its actual deformation.The contact constraint method can reduce the relative errors between simulated and experimental results.Abstract. Numerical simulation is an important method for revealing the working principle and optimizing the design of drip emitters. The hydraulic performance of pressure-compensating (PC) emitters is determined by the interaction between the elastic diaphragm and the flow field; therefore, correct deformation of the elastic diaphragm is one of the factors determining the accuracy of numerical simulation of PC emitters. This study investigated the effects of three constraint methods of the elastic diaphragm on the numerical simulation of PC emitters. The three methods were fully fixed constraint (FFC), upper surface fixed constraint (UFC), and contact constraint (CC). Fluid-structure interaction (FSI) simulation was used to analyze the deformation characteristics of the elastic diaphragm, the flow field characteristics, and the flow rate of the PC emitter. The simulated diaphragm deformation and flow rates were compared with the results of a visual experiment and a hydraulic performance experiment, respectively. The simulation results showed that the constraint method affected the diaphragm deformation and flow field of the PC emitter. In comparing the simulation results with the experimental results, the CC method had the highest accuracy among the three constraint methods, but an extremely long computation time was required. The FFC method had the lowest accuracy but required less computation time. The accuracy of the UFC method was lower than CC and higher than FFC, but its computation time decreased by 60.03% compared with CC. This study provides a foundation for further research on the numerical simulation and design of PC emitters. Keywords: Constraint method, Deformation characteristics, Flow field characteristics, Fluid-structure interaction, Visual experiment.

Computational and numerical simulations for the deoxyribonucleic acid (DNA) model

&lt;p style='text-indent:20px;'&gt;In this research paper, the modified Khater method, the Adomian decomposition method, and B-spline techniques (cubic, quintic, and septic) are applied to the deoxyribonucleic acid (DNA) model to get the analytical, semi-analytical, and numerical solutions. These solutions comprise much information about the dynamical behavior of the homogenous long elastic rods with a circular section. These rods constitute a pair of the polynucleotide rods of the DNA molecule which are plugged by an elastic diaphragm that demonstrates the hydrogen bond's role in this communication. The stability property is checked for some solutions to show more effective and powerful of obtained solutions. Based on the role of analytical and semi-analytical techniques in the motivation of the numerical techniques to be more accurate, the B-spline numerical techniques are applied by using the obtained exact solutions on the DNA model to show which one of them is more accurate than other, to explain more of the dynamic behavior of the homogenous long elastic rods, and to show the coincidence between the different types of obtained solutions. The obtained solutions verified with Maple 16 &amp;amp; Mathematica 12 by placing them back into the original equations. The performance of these methods shows the power and effectiveness of them for applying to many different forms of the nonlinear evolution equations with an integer and fractional order.&lt;/p&gt;

Structure Design of Disposable Ocean Temperature Depth Sensing Probe Based on F-P Cavity and FBG

The basic principle of sensing is the combination of F-P cavity interference and fiber grating reflection. A hybrid structure sensor probe has been designed based on the combination of an F-P cavity of liquid-filled thermometer structure, and a fiber grating with an elastic diaphragm, herein F-P cavity is used for temperature sensing, and the fiber grating is used for pressure sensing. By adopting the dual optical path structure, the dual-parameter detection of temperature and depth is realized, which solves the problem of low accuracy caused by the cross response of temperature and pressure of a single sensor device and the calculation of the depth information of the ocean with empirical formulas. Compared with traditional sensors, the sensitivity is effectively improved. Theoretical analysis shows that the sensitivity of the F-P cavity with a thermometer structure filled with kerosene reaches 1.334 nm/?C, and the depth sensitivity of the fiber grating is 284.6 pm/Mpa within the ocean depth range of 0 - 400 m.