Fractional-order modelling and system identification of a permanent-magnet induction flowmeter for ionically conductive liquids

Assessment of hydraulic jump dynamics on sediment deposition in river Orisa, Omu-Aran, Nigeria

Abstract This study experimentally investigates the thermal-hydraulic performance and flow instability characteristics of a two-phase natural circulation loop (NCL) using the FASSIP-06 facility, representative of passive heat removal systems in advanced water-cooled reactors. The system comprises a water heating tank (WHT), a water cooling tank (WCT), and a rectangular loop with a 3-inch hot leg and 1-inch cold leg operating at atmospheric pressure. Heater power (3000-4000 W) and coolant flow rate in the WCT jacket (3-7.5 LPM) were systematically varied to assess their effects on circulation dynamics. Temperature distributions were measured using 16 thermocouples, while volumetric flow rate was monitored by a magnetic flowmeter and supported by flow visualization in a transparent riser. Increasing heater power from 3000 W to 4000 W enhanced steady-state circulation by up to 33% in volumetric flow rate. The operating point of 4000 W and 7.5 LPM achieved the fastest transient response, reaching steady state at 4863 s with the highest outlet temperature and flow rate, but also exhibited the strongest oscillations. In contrast, 3000 W and 5 LPM produced the most stable operation with longer stabilization time and reduced oscillation amplitude. Flow visualization at 3000 W and 3 LPM documented transitions from bubbly to slug, churn, and annular flow between 85 °C and saturation. The resulting benchmark data and identified stability window support the design and optimization of two-phase NCL-based passive cooling systems for small modular and advanced reactors.

Research and Design of Non-Contact Electromagnetic Flowmeter

Flow measurements in molten salt are. Flow rate measurement using a thermal wave flow meter is a simple and reliable flow rate measurement not limited only to molten salts. The present study focuses on verifying and analyzing the thermal wave flow meter. Several flow meter settings were tested in order to evaluate flow meter accuracy and reliability. The flow meter was verified on a testing loop with water where an electromagnetic flow meter was used for a reference. First tests showed sensitivity of flow meter on heat pulse length and accuracy of peak location searching for a time delay evaluation.

Abstract Accurate flow monitoring in sewage networks is essential for public health and environmental management. Ultrasonic Doppler flow meters (UDFMs) are non-invasive and widely used, yet their readings can deviate by nearly 90% under fluctuating water levels and turbidity, making calibration difficult and expensive. To address this challenge, a neural-network–based end-to-end calibration framework is introduced. An end-to-end calibration dataset is constructed by collecting UDFM measurements under varying turbidity and water level conditions along with actual flow values measured by an electromagnetic flow meter. Building on this dataset, the core model RatioNet, a rational-polynomial neural network, captures the nonlinear mapping between meter readings and actual flow. By directly learning this mapping, RatioNet reduces the initial measurement error from about 90% down to about 2%. This data-driven approach improves accuracy and efficiency, and greatly enhances the practicality of UDFMs for long-term sewage monitoring, offering significant economic and societal benefits.

This paper investigates the weight function distribution in the electromagnetic flowmeter with conductive pipe wall by combining the virtual current density method and COMSOL Multiphysics simulation software. It was found that the average weight function values were identical in any arbitrarily small annular domain in the pipe wall or fluid. Additionally, the ratio of the average weight function of the fluid domain to the pipe wall domain was only related to the ratio of their conductivity. Then a correlation for the average weight function ratio of the fluid and pipe wall was derived for the first time. The weight function correlation of the fluid domain was subsequently obtained by combining the physical meaning of the weight function. Finally, a theoretical model was derived based on the weight function correlation and the control equation of the electromagnetic flowmeter. The deviation between this model and the calculation results of the electromagnetic flowmeter model established by COMSOL Multiphysics was less than 4%.

Understanding flow dynamics in open-channel node systems is crucial for designing effective hydraulic engineering solutions and minimizing energy losses. This study investigates how junction geometry—specifically the lateral inflow angle (α = 45° and 60°) and the longitudinal bed slope (I = 0.0011 to 0.0051)—influences the water velocity distribution and hydraulic losses in a rigid-bed Y-shaped open-channel junction. Experiments were performed in a 0.3 m wide and 0.5 m deep rectangular flume, with controlled inflow conditions simulating steady-state discharge scenarios. Flow velocity measurements were obtained using a PEMS 30 electromagnetic velocity probe, which is capable of recording three-dimensional velocity components at a high spatial resolution, and electromagnetic flow meters for discharge control. The results show that a lateral inflow angle of 45° induces stronger flow disturbances and higher local loss coefficients, especially under steeper slope conditions. In contrast, an angle of 60° generates more symmetric velocity fields and reduces energy dissipation at the junction. These findings align with the existing literature and highlight the significance of junction design in hydraulic structures, particularly under high-flow conditions. The experimental data may be used for calibrating one-dimensional hydrodynamic models and optimizing the hydraulic performance of engineered channel outlets, such as those found in hydropower discharge systems or irrigation networks.

Theoretical model of electromagnetic flowmeter under annular conductivity distribution based on annular domain weight function

Traditional electromagnetic flowmeters are inherently prone to external interference and uneven velocity distribution during measurement, which severely limits their accuracy. In this study, an improved method is proposed, which optimizes the excitation drive waveform, performs multiple filtering and amplification of the electrode input, and uses a Complex Programmable Logic Device to achieve rapid switching between positive and negative induction signals. This enables smooth rectification and, in combination with software filtering techniques, achieves highly precise performance. Additionally, empty pipe detection is realized by recognizing excitation waveform and input waveform patterns. Experimental verification shows that the designed electromagnetic flowmeter achieves an accuracy of 0.1% within a flow velocity range of 0.1-15 m/s, with system repeatability errors of less than 1%. The results validate the effectiveness of the proposed method in high-precision flow measurement. The study demonstrates that high-precision detection can be achieved with minimal additional cost, which is important for industry applications.

Surgical mitral valve repair remains a challenging procedure. Although several repair techniques have been defined, data comparing their hemodynamic effects are lacking. The commercially available pulse duplicators are commonly used to simulate blood circulation through mechanical or 3D printed cardiac valves. However, due to the specific structure and working mechanism of the mitral valve, the experiments on surgical techniques require the use of biological tissues. Ex vivo lamb mitral valves are suitable for such experiments, but the methods for mounting these valves to the pulse duplicator system (PDS) are not well defined. To address this, we modified the system by 3D printing and silicone molding as a mitral valve holder. We excised the mitral valve from a lamb heart for each experiment, including its annulus and subvalvar apparatus. We implanted this into the atrioventricular (mitral) valve area of the test machine using the silicone holder. Papillary muscle tension was simulated by tying sutures around the chordae-papillary junctions and passing these sutures through the release hole at the bottom of the ventricular chamber. Initial testing of the valve competence was conducted at a heart rate of 120 beats per minute and a cardiac output of 2 L/min. Valve regurgitation and the pressure gradient between the atrial and ventricular chambers were measured using pulse duplicator electromagnetic flowmeters and validated with echocardiography. Baseline hemodynamic testing demonstrated consistent valve function across five experiments, with a mean regurgitation fraction of 21.1% and echo-derived transmitral gradients ranging from 5.15 to 8.13 mmHg. Stroke volumes and peak flow rates varied among specimens, reflecting physiological variability within the pediatric model.

This study investigated the possibility of using the Discrete Cosine Transform (DCT) method for Time-of-Flight (ToF) estimation in ultrasonic water flow measurements, as an improvement over traditional correlation-based techniques. A DN-20 ultrasonic water flow meter was employed to collect data across 13 distinct flow rates, calculating the travel time of signals through the medium. The average flow readings were compared against reference values obtained from an electromagnetic flow meter. The DCT method demonstrated superior performance, consistently yielding lower error percentages than the correlation method. At low flow rates, such as 16 L/h, the DCT method achieved an error of 4.62%, compared to the 4.75% obtained with the correlation method, while at higher flow rates, such as 4000 L/h and 5000 L/h, the DCT method maintained minimal errors of 0.02% and 0.06%, respectively, versus the 0.05% and 0.07% attained with the correlation method. The DCT method's computational efficiency, derived from its frequency domain analysis, significantly reduced the required computational resources, as well as its robustness to noise, ensuring more accurate ToF estimates in noisy environments. Overall, the DCT method offered a more accurate, efficient, and robust alternative for ToF estimation in ultrasonic flow measurements. These findings suggest potential improvements in various applications requiring precise flow measurement, with future research focusing on integrating the DCT method into embedded systems and extending its applicability to other types of flow measurements.

The article is devoted to solving the problems of automation of the pasteurizer in LLC «Baltika Brewing Company» - «Voronezh Brewery» to improve the quality of control. The control system structure was developed based on the SIEMENS S7-400 controller, input/output modules SM321, SM331, SM322, SM332 and IEI PPC-5190A touch panel. The equipment includes local automation tools: SENSYCON PT100 temperature sensors; Endress+Hauser Cerabar S PMC631, Aplysens 0…10 bar pressure sensors; Endress+Hauser electromagnetic flow meters; HAFFMANS-PENTAIR oxygen meter; Enress+Hauser CLD134-PLC148AB2 conductivity meter; SPIRAX SARCO valves. The DANFOSS 131B2132 FC-302 frequency converter was adjusted to control the pump to enable working with small beer flows. Algorithmic and software support for the SIEMENS S7-400 control controller (Step7 environment) and the IEI PPC-5190A touch panel (WinCC environment) has been developed. To control the pasteurization process, it is proposed to implement a scheme for combined beer temperature control (steam flow rate) with disturbance compensation based on the heating steam pressure in the pipeline. To synthesize the algorithm for digital combined control, discrete dynamic models of the control channel (“heating steam flow rate – beer temperature at the pasteurization section outlet”) and the disturbance channel (“steam pressure in the coolant supply pipeline – beer temperature at the pasteurization section outlet”) were identified. The channel models were identified based on the experimental data obtained on the pasteurizer using the least squares method (LSM). A numerical optimization method (coordinate descent method) was used to calculate the settings of the digital PID controller and compensator for the control and disturbance channels. Model experiments were conducted, which showed that the use of this algorithm significantly reduces the fluctuation of beer temperature during pasteurization. To synthesize the algorithm, the author's programs for identifying discrete dynamic models of object channels and optimizing the settings of digital regulators and compensators were used. The process control system was put into operation.

Accurate grouting flow measurement is critical for optimizing construction quality and reducing material waste in geotechnical engineering. While electromagnetic flowmeters are widely used, their precision deteriorates significantly under low-flow conditions. This study proposes a laser ranging-based method to address this limitation by analyzing slurry liquid level fluctuations in mixing drums. Through theoretical modeling, indoor experiments, and numerical simulations, the liquid level fluctuation patterns under varying water-cement ratios (0.5:1–5:1) and stirring speeds (40–80 r/min) were investigated. Key findings reveal that liquid level stability increases radially outward from the stirring shaft for ratios ≥ 0.7:1 but inversely for 0.5:1. The slurry surface was categorized into three zones: a turbulent central zone (within 1/3 radius, R/3), a stable intermediate zone (R/3–7R/8), and a high-fluctuation wall zone (7R/8–R). Optimal sensor placement in the stable zone reduced measurement errors to 0.83% (power-function-distributed sensors) and 1.12% (uniformly spaced sensors), significantly outperforming electromagnetic flowmeters (up to 20% error). This work provides a validated framework for sensor layout optimization, enhancing the reliability of laser-based grouting flow detection in practical applications.

As a common volume flow measuring instrument, an electromagnetic flowmeter (EMF) is widely used in various fields and plays an important role. With the development of EMFs in the direction of complex fluid measurement, further improving their measurement accuracy is becoming increasingly urgent. The optimization research of EMF is the key to reducing measurement error and eliminating the influence of interference noise. This article reviews the latest optimization technology for circular pipeline EMFs. First, the optimization technology of the EMF sensor is introduced, including the optimization of the excitation coil and signal electrode. Then, the optimization technology of the EMF converter is discussed, including the optimization of signal excitation mode and signal processing method. Finally, the future development trend of EMF optimization technology is discussed, and the work is summarized. This review compares different optimization techniques for EMFs and demonstrates their effectiveness in improving flow measurement accuracy. This article can provide valuable research references for researchers in the field of instrumentation who use EMF optimization technology to measure single-phase flow or multiphase flow to keep in touch with the latest research progress in this field.

A new method was proposed for calibrating large electromagnetic flow meters using small flowrates. The method has traceability and can be theoretically supported. It can avoid using large volume flow rigs and much power consumption. Preliminary experiment was done. Theoretical analysis was given briefly. Uncertainty of the method was discussed.

Research on measurement characteristics of electromagnetic flowmeter with sensor installed at rectangular cross section

Simulation method for modeling the operation of magnetic flowmeters

Piping and overtopping are the most important causes of earth-fill dam failure. Such dams may erode under seepage, causing a reduction in the structural strength. The aim of this study was to investigate the temporal evolution of the breach and flow rate from the breach resulting from the piping in earth-fill dams. The experiments were carried out at Hydraulics Laboratory of Civil Engineering Department within İzmir University of Economics. The dam was constructed by using a mixture consisting of 85 % sand and 15 % fine (low plasticity clay). In the first scenario a circular tunnel with a diameter of 2 cm was created along the centreline at 6 cm below the dam crest whereas in the second one it was located at the upper edge. Six cameras at different locations recorded the evolution of the progress of the breach formation. The pump flow rate was measured by magnetic flow meter, and the continuity equation was used to calculate the flow rate values from the breach. The time-varied values of the total breach areas were determined using the Gauss Area formula. The image processing method was also applied in the determination of the breach areas. The time-dependent changes of water depth in the channel were also recorded. The obtained experimental findings are presented and commented, together with the universal dimensionless curves. The failure of the dams occurred mainly because of the headcut erosion developed from downstream to upstream. When breaching started, the orifice flow was converted to open channel flow where breach bottom behaved like a broad crested weir. In the second scenario, the rigid lateral side considerably influenced the flow rate and the development of the breach. The peak flow rate corresponding to the first scenario was found approximately 2.3 times greater than that of the second one. The maximum values of all the breach parameters were reached earlier in the case of the seepage along the centerline. The ratios between the values corresponding to the first and the second scenarios were found as 3.25 and 1.75 for maximum breach areas at downstream and at upstream sides, respectively. These ratios were 2.44 and 1.37 for the average breach widths at downstream and upstream sides, respectively. A very good agreement was found between the area values obtained from Gauss area method and image processing technique, in both scenarios. This fact demonstrated that either of these two approaches can be used to determine the time-dependent breach areas. These experimental findings provide the opportunities for the calibration and validation of the numerical models used in the relevant numerical investigations. This study also offers guidance for the strategies concerning emergency action plans related to the failure of homogeneous earth-fill dams when the piping starts at upper part of the homogeneous earth-fill dams.

The Lawas community in Sarawak, especially in the town area, heavily depends on treated water from the Trusan Regional Water Treatment Plant (WTP) for daily water needs. However, the hilly and remote areas face several challenges, such as deteriorated water distribution, inadequate supply, and low water pressure. These issues are worsened by the increasing number of new water meter connections each year and the difficulties in supplying water to remote areas. As a result, there have been more complaints to water authorities from the community due to the impact on their essential survival needs. This study aims to comprehensively investigate, analyse, and assess water demand and residual water pressure to determine if the current water supply is sufficient for the population in Lawas. By utilising population data from the 2022 Lawas District Office and recent water pressure measurements obtained using a Pressure Gauge and Prime Log, along with water flow data collected using a Portable Ultrasonic Flow Meter (PT900), Electromagnetic Flow Meter, and Insertion Flow Meter, this research identifies the factors contributing to the inadequacy of water demand. The recommended solutions optimise water pressure and flow to ensure reliable data for future operations and maintenance. These findings provide a reference for designing an efficient water distribution system and promoting optimised water usage tailored to specific areas based on their needs.