Water Flow In Pipe Research Articles

Exploring the air impacts on the state development of pipe flow using the smooth particle hydrodynamic method

Abstract It is widely recognized that the water flow in pipes can be affected by trapped air pockets. However, the underlying air–water interactions of free flow with non-jacking downstream of the pipe are rarely investigated. There are no studies at this time that clearly elucidate the differences in pipe flow between the vacuum and the presence of air in the free flow case. To this end, the smoothed particle hydrodynamics (SPH) method is applied to study the air–water hydraulic dynamics in the pipe under free flow. We perform SPH simulations in several different scenarios and find that (i) the SPH method is competent to simulate both single- and two-phase flows in the pipe due to its outstanding advantages in capturing complex interfaces; (ii) only when the upstream water level is higher than the top of the pipe inlet, and the water level in the pipe rises to the top of the pipe due to air resistance, can a full pipe flow be formed; and (iii) the presence of air can cause the water to form a full pipe flow, causing a siphon-like effect that promotes pipe drainage. These results provide insights into the underlying complex air–water hydraulic properties in pipe flows.

Design of optical fiber Bragg grating-based sensors for flow measurement in pipes

In this work, optical Fiber Bragg grating (FBG) sensors were used to measure water flow in pipes. Several types of coatings were incorporated into the design of the sensors to examine their effects on the elastic strain that the fiber underwent as a result of the water flow. ANSYS-CFX V2020 R2 software was used to model the elastic strain encountered by the fiber under various flow rates in order to assess the performance of the FBG sensors. The calculations and experimental data exhibited good convergence, demonstrating the accuracy of the FBG sensors in determining water flow. These calculations and procedures can be extrapolated to any other fluid.

Hydraulic-thermal coupling dynamic models based on mechanism and data-driven methods of the heating networks in integrated energy systems

The district heating is expected to play a crucial role in the decarbonization of integrated energy systems within the context of attaining carbon neutrality. The literature review reveals a research gapin the investigation of models that account for thehydraulic-thermalcouplingdynamiccharacteristics of heating networks in integrated energy systems, particularly those based on the flow-regulation mode. This discrepancy may affect the safety of the heating networksand contribute to the inefficient scheduling of integrated energy systems, which motivates this study. In this study, it refutes the harsh hypotheses in previous studies, making it more closely related to the real hydraulic and thermal conditions of heating networks. A mechanism-driven model is proposed, which involves the coupled hydraulic and thermal dynamic characteristics of heating networks. The modified forward–backward iteration as a calculation method is carried out, which is embedded with the method of characteristic and upwind difference. A data-driven hydraulic-thermal dynamic model is proposed for fast calculations. For model validation and case analysis, three heating networks in the integrated energy systems are utilized. The simulation results indicate that1) The hydraulic and thermal average relative errors between the measured data and the simulation results are 0.396% and 0.091%, respectively, validating the effectiveness of the proposed dynamic mechanism model; 2) Compared to the current quasi-dynamic model, the proposed dynamic mechanism modelcould reflect the characteristics of heating networks more accurately and simulates the dynamic processes with higher resolution. These results demonstrate that the fluctuations of water head and pipe flow can reach 61.24 ∼ 237.53 m and −4.26 ∼ 32.16 kg/s, respectively. The average temperature difference between the two models is around 0.264 °C; 3) Compared to the forward–backward iteration, the modified forward–backward iteration has a superior convergence performance and calculation accuracy; 4) Compared to the quasi-dynamic model, the proposed data-driven model increases the overall accuracy of hydraulic-thermal calculations and significantly reduces the amount of time required. The average calculation time of the data-driven model is 0.0349 s, while those of the quasi-dynamic model and the proposed mechanism model are 352.92 s and 624.13 s, respectively. In conclusion, the proposed mechanism model of hydraulic-thermal coupling calculation and the related data-driven model are suitable for the dynamic simulations of heating networks in integrated energy systems.

Different Experimental and Numerical Models to Analyse Emptying Processes in Pressurised Pipes with Trapped Air

In hydraulic engineering, some researchers have developed different mathematical and numerical tools for a better understanding of the physical interaction between water flow in pipes with trapped air during emptying processes, where they have made contributions on the use of simple and complex models in different application cases. In this article, a comparative study of different experimental and numerical models existing in the literature for the analysis of trapped air in pressurised pipelines subjected to different scenarios of emptying processes is presented, where different authors have develope, experimental, one-dimensional mathematical and complex computational fluid dynamics (CFD) models (two-dimensional and three-dimensional) to understand the level of applicability of these models in different hydraulic scenarios, from the physical and computational point of view. In general, experimental, mathematical and CFD models had maximum Reynolds numbers ranging from 2670 to 20,467, and it was possible to identify that the mathematical models offered relevant numerical information in a short simulation time on the order of seconds. However, there are restrictions to visualise some complex hydraulic and thermodynamic phenomena that CFD models are able to illustrate in detail with a numerical resolution similar to the mathematical models, and these require simulation times of hours or days. From this research, it was concluded that the knowledge of the information offered by the different models can be useful to hydraulic engineers to identify physical and numerical elements present in the air–water interaction and computational conditions necessary for the development of models that help decision-making in the field of hydraulics of pressurised pipelines.

Research of water flow measuring device based on Arduino platform

The article provides information about modern methods and devices for measuring water flow in pipes in the irrigation system. To create a device suitable for an automated system for calculating water flow in pipes, and sending information about water flow via Bluetooth and GPRS module, the possibility of using the base of the Arduino platform was considered. A YF-S201 transducer was used to determine the water flow in the pipe. The article presents the experiment results based on a laboratory stand. Based on the Arduino UNO board and laptop, the measurement results were processed, as well as the remote transmission of data and their visualization on a smartphone. The linearity and error of the static characteristic of the proposed water flow detection device were investigated.

Effect of non-condensable gas on submerged steam jet condensation in a narrow pipe

A visualization study was performed to investigate the effect of non-condensable gas on stable submerged steam jet condensation in water flow in a narrow pipe. The direct contact condensation (DCC) characteristics including jet plume shapes, dimensionless penetration length and average heat transfer coefficient were analyzed in a wide range of water flow subcooling, Reynolds number of water flow and steam–air mixture flow rates. As four different steam plume shapes for pure steam jet in subcooled water flow in a pipe were reported in the previous research, the effect of non-condensable gas on the four steam plume shapes was investigated by introducing a certain amount of air into steam. In the current study, the submerged steam–air mixture jet behavior was investigated through direct visualization techniques. The effect of non-condensable gas on jet plume shapes was recorded by using a high speed camera. The gas–liquid interface and the dimensionless penetration length was obtained by digital image processing method implemented by a MATLAB subroutine. Then the average heat transfer coefficient was calculated based on thermal equilibrium of gas–liquid interface. In the experiment, the gas mass flux at nozzle exit was within 320–780 kg/m2/s, with no more than 1 % non-condensable gas. The results indicated that the non-condensable gas plays an important role on the gas–liquid interface, jet penetration length and heat transfer coefficient. It was found that when 1 % non-condensable gas was mixed with steam jet, the dimensionless penetration length was extended by 16–70 %, and the average heat transfer coefficient decreased by 12–50 %. Based on the force-balance of jet plume, a new quantitative correlation for the steam–air mixture jet penetration length was proposed. The predicted jet penetration length agrees well with the experimental measured values.

IDENTIFIKASI PENYUMBATAN ALIRAN AIR PADA PIPA DENGAN METODA GETARAN

The piping system design due to pressure will experience vibrations due to the excitation force that comes from the pump. Excitation force occurs due to changes in fluid flow velocity. In addition, the length of the pipe and the large number of bends of the pipe due to cross with other installations, cause vibrations in the pipe. vibration analysis in the pipe should not be underestimated, where it is necessary to identify the causes of vibration in the pipe due to flow and placement of good support and the effect of obstacles in the pipe flow to prevent failure of the pipe. In addition, clogging of pipelines can result in reduced system carrying capacity, wastage of energy and resources, and the potential for increased likelihood of environmental and health problems. Therefore, this study will discuss the identification of blockage of water flow in pipes using the vibration method. The excitation force comes from the fluid flow flowing in the pipe, while the vibration response is generated using the accelerometer sensor provided with the FFT Analyzer. Retrieval of data using the accelerometer as a vibration sensor served by Ono Sokki's FFT analyzer which is then analyzed using Matlab. Installation with four supports shows that the resonance that occurs in the installation of two supports can be reduced, but it causes the magnitude of the iron pipe to increase, while the PVC pipe decreases at a frequency of 5 Hz. In general, the result of installing four supports shows that the noise on the PVC pipe is reduced while the iron pipe is getting higher due to the installation of a barrier in the pipe due to water flow. The vibration pattern that occurs uses a harmonic response simulation, the vibration pattern that occurs uses a harmonic response simulation.

Simulation of pulsed neutron activation for determination of water flow in pipes

Abstract The effect of the asymmetric distribution of activated water in PNA (pulsed neutron activation) measurements has been investigated experimentally by depositing a small amount of colour, simulating the activated water, in a transparent Plexiglas pipe. Based on the colour experiments, a semi-empirical model has been developed that describes the distribution of the activated water at different distances from the activation point. The model shows that the combination of inhomogeneous activation and a radial velocity profile makes the mean velocity of the activity lower than the mean velocity of the water. It can also be seen that the velocity of the activity increases as the distance from the activation point increases. The model has been compared with experimental values from PNA measurements and the measured mean velocity shows a similar dependence on the distance from the activation point.

Flow characteristic of steam jet condensed into a water pipe flow - a numerical study

• Numerical simulation of steam jet condensation in subcooled water flow is conducted. • Thermal hydraulic parameters of cone and cylinder-cone steam plumes are analyzed. • The total pressure in the centerline reaches maximum at steam volume fraction 0.01. • Heat transfer coefficients based on area and volume of two-phase region are obtained. Gas-liquid two-phase jet condensation has a property of high heat and mass transfer efficiency, thereby its theory and method becoming an urgent requirement for optimization design and safe operation of various industrial processes. Based on the experimental study of steam jet condensation in subcooled water flow in a vertical pipe, we have developed a numerical simulation method of steam-water two-phase jet condensation coupled with thermal phase change model and two-fluid model. Meanwhile, we emphasize on the shape of the steam plume, the distribution of pressure and velocity, and the heat and mass transfer of the two-phase interface. As the steam mass flux increases from subsonic to sonic, the steam plume becomes longer, and its shape transforms from cone to cylinder-cone gradually. The steam volume fraction is close to 0.01 at the end of the two-phase region, where the total pressure in the centerline approaches the total pressure of the water and reaches the maximum. The mass transfer process of steam condensed into liquid mainly occurs in the gas–liquid two-phase region, accompanied by drastic parameter change in pressure and velocity. Under the working conditions of this paper, the heat transfer coefficients based on the interfacial area of the steam plume and the volume of the two-phase region range from 1.71 MW/m 2 K to 3.51 MW/m 2 K, and from 2398.80 MW/m 3 K to 5040.07 MW/m 3 K, respectively.

Interfacial characteristics of steam jet condensation in subcooled water pipe flow – An experimental and numerical study

Subsonic and sonic steam jet condensation in subcooled water pipe flow is investigated experimentally and numerically. Steam plumes are captured using a high-speed camera, and thermal hydraulic parameters and heat and mass transfer are revealed by a two-fluid model coupled with a phase change model. As the Reynolds number of water increases, the steam plumes show a conical shape and gradually shorten in length. The steam dynamic pressure suddenly drops at the nozzle outlet, and the water dynamic pressure rises sharply to the maximum at the end of the two-phase region where the steam volume fraction is 0.001. Starting from the single-phase region, the pressure, velocity and temperature of the jet are self-similar. The heat and mass transfer mainly occur in the two-phase region with steam volume fractions between 0.01 and 0.99, and the mass transfer reaches the maximum at the phase interface with the steam volume fraction of 0.60.

Stereo PIV measurement of diffuser swirling flow

The swirling flow in a diffuser has been studied using the stereo PIV technique. The DANTEC hardware and software were used for the experiment. The water pipe flow in the diffuser inlet has been set spinning by introducing tangential jet flow. Both piping and diffuser were of circular cross-section, however diffuser casing had rectangular (square) cross-section. The plane of measurement was located perpendicular to the flow within the diffuser. The two cameras with the Scheinpflug lens mounting were used, however the angle between the lenses axes and the diffuser outer surface was far from to be perpendicular, as recommended in similar situations. This configuration has been dictated by technical conditions in the laboratory. The two-level calibration target with dots was used for the cameras calibration. The calibration covers the diffusers central region in a good quality, however regions close to the walls were not well resolved. Many combinations of axial and tangential inflow conditions have been studied. The acquisition covered about 3 seconds in real time with frequency 500 Hz. Both statistics and dynamics of the flow have been studied in details. Results are shown for both statistical characteristics and dynamical analysis of various conditions. During experiments the air-glass-water interface was not normal to the camera viewing axis. The discussion how to solve this problem and of the bias of the calibration will be introduced.

Numerical investigation on thermal hydraulic characteristics of steam jet condensation in subcooled water flow in pipes

Because of the high efficiency of heat and mass transfer, the direct contact condensation of the steam jet in subcooled water has been widely used in various industrial processes. Based on the previous experiments, this paper has established the numerical model and simulation method to describe the condensation of saturated steam discharging into the subcooled water in the pipe through the nozzle. Within the frame of the Euler-Euler two-fluid model, the heat and mass transfer in the condensation phase change of steam is calculated by the thermal phase-change model. When the steam pressure at the nozzle inlet increases from 150 kPa to 450 kPa, the steam plume gradually transforms from contraction cone to expansion-contraction cone. The length of the steam plume increases linearly from 0.59de to 3.07de. The condensation heat transfer coefficient based on the volume of the two-phase region gradually decreases from 4847.01 MW/m3K to 1988.16 MW/m3K. By analyzing the distribution of thermal-hydraulic parameters along the nozzle central axis, it is found that the expansion-contraction steam plume channel accelerates the steam jet to a supersonic state. The total pressure decreases suddenly at the nozzle outlet, and the water phase dynamic pressure causes the total pressure to rapidly increase to the maximum at the end of the gas-liquid two-phase region. When the steam pressure at the nozzle inlet is 450 kPa, the Ma number and maximum total pressure are up to 1.43 and 1228.2 kPa, respectively.

Evolution of waves in a horizontal pipe propagating on a surface of a liquid film sheared by gas

Different wavy regimes in stratified air–water pipe flow are determined for a wide range of gas and liquid flow rates in a 10 m long horizontal pipe with a diameter of 24 mm. Three sub-regions of wavy stratified flow are identified: ripples, roll waves, and pre-annular wavy flow. Statistical parameters, such as local mean film thickness and its higher moments (root-mean-square, skewness, excess kurtosis) as well as wave characteristics (mean heights and wave height distributions, lengths, propagation velocities, etc.), are measured and analyzed. It is demonstrated that ripples are essentially linear waves and their propagation velocities are described reasonably well by linear wave theory. High amplitude roll and pre-annular waves are substantially nonlinear, and their propagation velocities differ significantly from that of ripples. Transition to roll waves causes a sharp increase in higher statistical moments. Evolution of wave and statistical parameters characterizing each sub-region of stratified gas–liquid pipe flow is studied. Simplified models describing roll waves are presented; the model predictions are verified by experiments.

A comprehensive model for simulating supercritical water flow in a vertical heavy oil well with parallel double tubes

At present, there is no research on parallel double pipe injection of supercritical water. The research on the process of SAGD supercritical water injection is insufficient. This paper first established a mathematical model of parallel twin-pipe injection supercritical water pipe flow. On this basis, the SAGD supercritical water injection development numerical model was established using numerical simulation software, and the variation characteristics of the temperature field, crude oil viscosity field and oil saturation field in the reservoir were analyzed. The main conclusions obtained are as follows: (a) the high temperature area first developed from the lower part of the vertical well. (b) After 150 days, the temperature in the reservoir gradually increased. (c) When the injection time reaches 210 days, the viscosity of the heavy oil between the vertical wells has been sufficiently reduced. (d) Condensed water occupies a lot of pore space, resulting in a decrease in oil saturation.

Oil Fraction Measurement of Nonuniform Dispersed Oil–Water Two-Phase Flow Based on Ultrasonic Attenuation

Oil volume fraction determination is important for the transportation and separation of oil–water dispersed flow in petroleum industry, for which ultrasound method is suitable with the advantages of good penetration and low cost. The existing ultrasonic attenuation methods are based on homogeneous media for the determination of phase fraction without considering the effect of inhomogeneity on attenuation. In this article, the fractal approach is introduced to modify the acoustic attenuation model by characterizing the inhomogeneity of the dispersed phase in pipe flow, which establishes the relationship between multi-frequency attenuation and droplet size distribution. Then, an improved covariance matrix adaptive evolutionary strategy (CMA-ES) based on the established attenuation model is proposed to estimate oil volume fraction, which combines restart strategy with local search strategy to enhance the search performance and avoid falling into local optimum. Moreover, a demodulation method based on swept-frequency chirp is designed for the time-varying dispersed oil–water pipe flow to quickly obtain the multi-frequency attenuation. The effectiveness of the fractal-based modified attenuation model and the improved CMA-ES is verified by numerical simulations and flowing experiments. The experimental results at different oil volume fractions and flow rates indicate that the fractal-based modified attenuation model can effectively reduce the impact of nonuniform distribution of dispersed phases on the attenuation measurement, and thus effectively improve the measurement accuracy of the oil volume fraction, especially for the dispersed flow in the horizontal pipe.

Bubble formation in globe valve and flow characteristics of partially filled pipe water flow

Air bubble entrainment is a phenomenon that can significantly reduce the efficiency of liquid motion in piping systems. In the present study, the bubble formation mechanism in a globe valve with 90% water fraction flow is explained by visualization study and pressure oscillation analysis. The shadowgraph imaging technique is applied to illustrate the unsteady flow inside the transparent valve. This helps to study the effect of bubbles induced by the globe valve on pressure distribution and valve flow coefficient. International Society of Automation (ISA) recommends locations for measuring pressure drop of the valve to determine its flow coefficient. This paper presents the comparison of the pressures at different locations along with the upstream and the downstream of the valve with the values at recommended positions by the ISA standard. The results show that in partially filled pipe flow, the discrepancies in pressure between different measurement locations in the valve downstream are significant at valve openings less than 30%. The aerated flow induces the oscillation in pressure and flow rate, which leads to the fluctuation in the flow coefficient of the valve. The flow coefficients have a linear relationship with the Reynolds number. For the same increase of Reynolds number, the flow coefficients grow faster with larger valve openings and level off at the opening of 50%.

Evaluation of the effect of the concentration of seeding particles on spike-excitation doppler UVP measurement

In the study of fluid flows, one of the important parameters is the spatial-temporal velocity distribution. Experimental measurement of the parameter is required for the development and validation of various models in this field. Techniques for the measurement of flow velocity at single points have been in operation with great success for many years. However, there are situations where the measured data at one point is obviously not enough to understand structures in, e.g., turbulent/transient flows. One of the well-established and powerful methods for measuring velocity distribution is the UVP - Ultrasonic Velocity Profile method that enables measurements of the instantaneous velocity profile along a measurement line, i.e. the sound path. The new application of spike excitation along with the Doppler signal processing to the UVP method has recently been successfully tested. Regarding this new method, factors influencing the measurement result require further careful investigations. This study addresses, to some extent, the effect of the seeding-particle concentration on the results of spike-excitation UVP measurements. For the investigation, experimental measurements of water pipe flow have been carefully executed for a wide range of the particle concentration. The dependence of the measured data on the particle concentration is evaluated and reported. The result of this study suggests an appropriate range of the seeding-particle concentration in setting up spike-excitation UVP measurements.

The hydraulic resistance paradox in rapid narrow pipe waterflow

In this work we present experimental results of cross-sectional speed of water flow in narrow cylindrical metal tubes at high pressure gradients up to 1.1 GPacdotm−1. The measurement draws attention to the paradoxical behaviour of flowing water in internal diameters less than 250 upmum. At constant pressure gradient, its cross-section speed decreases with decreasing diameter in accordance with the classical hydrodynamic prediction for turbulent flow in rough cylindrical tube. However for very low diameters below 250 upmum, the cross-section speed rises again and reaches almost the maximum theoretical value of the outflow speed for the appropriate pressure without energy loss caused by contraction or hydraulic friction. Our contribution describes mainly experimental character of the new phenomenon and its motivation is to promptly provide the material for further study to the professional public.

Optimization of system and piezoelectric effect on PZT crystal

• The piezoelectric transducer was used to measure the reference pressure of Lead Zirconate Titanate (PZT) crystal material. • The different types input factors such as operating voltage, rated current and resonant frequency were used to found the pressure. • The most influential factor which affects the pressure was measured through variance analyze. • The optimal pressure of PZT crystal was evaluated through taguchi method. The pressure sensing technology is playing an essential role in hydraulic system, water flow in pipes, blood pressure in human body, oil and gas plants. The measurement of pressure, force and stress on the piezoelectric material is difficult. The piezoelectric transducer was used to measure the reference pressure of Lead Zirconate Titanate (PZT) crystal material. It has fast response with dynamic load, self power and simple circuits. For this experimental work, the different types input factors such as operating voltage, rated current and resonant frequency were used to found the response such as pressure. The most influential factor which affects the pressure was measured through variance analysis. The optimal pressure of PZT crystal was evaluated through Taguchi method.

Experimental Analysis of The Effect of Hydrophobic Coating on Pressure Drop in Small Pipes

In this paper, experimental results are reported to quantify the effect of hydrophobic coating LT-8 on frictional drag of water flow in pipes of 450 mm length. Five pipes of 1, 2, 3, 4, and 5 mm inner diameter were tested. The results from 1, 2 and 3 mm diameter pipes demonstrated an average frictional drag reduction of 9%, 11.5% and 3%, respectively, while the results from 4mm and 5mm pipes showed an increase in frictional drag of 12% and 10%, respectively. The 2mm and 4mm pipes were also tested with a half application of hydrophobic coating. The half coated 2mm pipe showed decrease in drag while 4mm pipe showed increase in drag. The results indicate a relationship between drag reduction/ increase within the percentage of coated surface. The main conclusions are, the flow changed from laminar state to the liquid-air wetting surface condition (Cassie-Baxter wetting state) at the pipe surface and then destabilized by the turbulent boundary layer and entered the liquid wetting surface (Wenzel wetting state) will be appeared. This transition lead to a reduction in friction drag for laminar flow condition and increase in drag for turbulent flow condition.