Channel Inclination Angle Research Articles

Research on erosion wear law of four-way flow channel of wellhead fracturing in ultra-deep wells

Abstract This paper establishes a 1/2 three-dimensional finite element model that considers multiple factors affecting the erosion rate of the four-way fracturing structure on site. The model can simulate the effects of different inlet velocities, dynamic viscosities, outlet quantities, outlet pressures, and channel wall angles on the velocity and streamline distribution of the four-way channel. It is also possible to analyze the effects of different factors such as inlet velocity, sand carrying mass flow rate, inlet quantity, fluid dynamic viscosity, fracturing fluid particle density, fracturing fluid particle diameter, four-way wall hardness, and channel wall inclination angle on the erosion of the inner wall. Through the established model calculation, it was found that as the inlet flow velocity increases, the maximum flow velocity in the channel also increases, and the value is close to 1.8 times the inlet velocity, with the maximum value appearing at the inlet corner. When the inlet velocity of the four-way valve is low, a significant vortex-like flow field appears in the closed flow channel of the four-way valve, which will lead to the accumulation of particles in the fracturing fluid. The calculation shows that the number and velocity of sand containing fracturing fluid inlets have the greatest impact on the erosion rate of the four-way flow channel, and the optimal inclination angle of the flow channel is 9 degrees. Increasing the hardness of the four-way wall can improve the maximum erosion rate of the flow channel wall, but changing the sand particle density and diameter has little significance in reducing the erosion rate of the four-way flow channel. It is recommended to perform corresponding heat treatment on the inner wall of the four-way valve to reduce the impact of sand containing fracturing fluid on wall erosion. This article provides a theoretical basis and guidance for controlling or avoiding erosion and thinning failure of four-way valves and also provides a theoretical basis for the design of wellhead four-way valves and various safe construction operations.

Performance analyses on the air cooling battery thermal management based on artificial neural networks

Air cooling thermal management technology is a lightweight and cost-effective approach for managing heat in power battery packs for electric ships. However, it suffers from significant drawbacks such as poor temperature control and excessive noise generation. To address these challenges, this study proposes a method that combines fluid dynamics and artificial neural networks (ANNs) to optimize the thermal management and aeroacoustic performance of the air cooling battery thermal management system (BTMS) for marine power batteries. Initially, a thermal-flow coupled model and an acoustic model for the BTMS were developed to investigate the impact of system structural parameters (battery spacing d, and main channel inclination angle θ) and operating parameter (system inlet velocity v) on the thermal management performance indicators (maximum temperature Tmax, and maximum temperature difference ΔTmax) as well as the aeroacoustic performance indicator (overall sound pressure level, OSPL). Subsequently, a relationship between the system structural and operating parameters and performance indicators was established using the 50-layer Residual Network (ResNet-50) model, enabling accurate and rapid prediction of the system thermal management and aeroacoustic performance. Furthermore, by combining ResNet-50 with the evaluation method of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), this study successfully obtained the optimal system structure and operating parameters. The research indicates that keeping the remaining parameters constant, increasing the battery spacing results in higher maximum temperature and maximum temperature difference, while decreasing the overall system sound pressure level. Conversely, increasing the main channel inclination angle results in lower maximum temperature and maximum temperature difference, but higher overall system sound pressure level. In addition, increasing the inlet velocity will result in higher maximum temperature and maximum temperature difference, as well as higher overall system sound pressure level. The optimal case were found to be a main channel inclination angle θ = 3°, battery spacing d = 2 mm, and inlet velocity v = 10 m⋅s−1. Compared to the base case, the optimal case shows a maximum temperature reduction of 10.63 K, a maximum temperature difference reduction of 9.41 K, and an overall sound pressure level reduction of 4.6 dB. The prediction errors for these values are 0.08 %, 2.64 %, and 1.36 % respectively. This research demonstrates an effective and rapid approach based on fluid dynamics and ANNs in the design and optimization of BTMS.

CFD-DEM numerical investigation of the effects of water content and inclination angle on interactions between debris flows and slit dam

Debris flows, composed of sediment–water mixtures, can pose significant risks to downstream populations and infrastructure in mountainous regions. Slit dams have been demonstrated as being effective measures for decreasing the destructivity of debris flows. Reliable evaluations of the interactions between debris flows and slit dams are challenging if the complicated component characteristics of debris flows, such as the water content, are not considered. Here, a multi-scale study of debris flows impacting a slit dam is conducted via computational fluid dynamics and discrete element method (CFD-DEM) simulations to understand the influences of the water content (controlled by solid volume fraction in this study) and the channel inclination angle on flow–slit dam interactions. The results indicate that both the initial solid volume fraction and the channel inclination angle have significant effects on the impact kinematics of flow–slit dam interactions and regulation functions of the slit dam: (i) For gentle slopes, the deposition of debris flows is primarily influenced by flume basal friction, and the normalized peak total impact forces have little difference for a given inclination angle, whereas for steep slopes, an overtopping can occur, further result in the increasing of the normalized peak total impact forces with the increase of solid volume fraction. (ii) The run-up height and retention efficiency are also analyzed to provide a scientific reference for optimizing the design of slit dams.

Unravelling the dependency of dross formations in metal additively manufactured channels as a function of channel diameter and inclination angle

Unravelling the dependency of dross formations in metal additively manufactured channels as a function of channel diameter and inclination angle

Second Law Investigation in a Non-Newtonian Liquid Flow in a Porous Channel with Circular Obstacle

The problem of non-Newtonian fluid flow has taken considerable interest and has been the subject of several work in latest years due to its various requests in different fields of engineering, in particular the interest in the problems of heat transfer in non-Newtonian liquids, such as lubrication, hot rolling, cooling problem and drag reduction. Here, mixed convection heat transport and its related entropy production in a porous channel with circular obstacle saturated via non-Newtonian power law liquid has been scrutinized. The influences on entropy production of the power law index, the Reynolds number, the Rayleigh number and the Darcy number are investigated. Being a novelty of this work, an optimization study of the thermodynamic irreversibility as a function of the channel inclination angle and the power law index is undertaken. The governing equations of the problem are solved employing the COMSOL software. Outcomes illustrate that the governing parameters strongly affect the entropy production. The thermal entropy generation is maximal at low value of power law index and high value of Reynolds number. The effect of Reynolds number become insignificant at relatively high power law index. At fixed Reynolds number value, a rise in the power index (n) leads to a reduce in the thermal entropy. This decrease is tiny, at low value of Reynolds number (Re) and turn into increasingly considerable as Re rises. The streamlines show the existence of two recirculation zones just after the circular obstacle, whose existence depends on both Re and power law index. Results show that the greatest variation relating to the inclination angle is for power law index equal to 0.4. Results indicate also that, at low Darcy number and relatively high power law index, the intrinsic effect of the modified Darcy number on Darcy viscous irreversibility become pronounced giving a sharp increase in the total entropy production.

Influence of inclination angle, shape and size of the flow channels on the AlSi10Mg complex products fabricated by selective laser melting

The design and manufacture of complex products with flow channels produced by the Selective Laser Melting (SLM) have attracted much attention due to its influence on the practicability of products. In this research, the inclination angle, shape and size of channel were compared on the complex products produced by SLM. Besides, the surface quality and forming difficulty of AlSi10Mg were investigated. As shown by the results, the overhang length played a key role in collapse, which was determined by inclination angle. In addition, the limited inclination angle was attributed to the position relationship between the inclination plane and the moving direction of the scraper. Meanwhile, the ridge-shaped flow channels had an advantage on surface quality and dimensional accuracy over the circular channel. No matter whether the section of the flow channels is circular or ridge-shaped, the size of the flow channels should be designed equal or >2 mm. The complex product with flow channels had been successfully produced by SLM without remaining powder or defects, which could withstand 2 MPa for 5 min. Furthermore, the CT test is suitable to investigate the forming quality of the flow channels, especially whether there is remaining powder inside the flow channels. Especially for the complex product with flow channels, it provides an integrated detection method based on X ray test and CT test for remaining powder, internal surface quality or internal defects. In addition, the design idea and criteria of three-dimensional flow channels based on the SLM technology provide a basis for the design of other products with flow channels.

Study on the influence of structural parameters on the flow and cavitation characteristics of tandem multi-stage pressure-reducing valves

Tandem multi-stage pressure-reducing valves (TMSPRV) are widely used for piping systems in the process industry. The flow coefficient is a central factor in valve design. The cavitation was caused by the local pressure of the fluid passing through the pressure-reducing valve being lower than the saturated steam pressure. Would cause serious damage to the pipeline system. Therefore, it is important to investigate systematically the effect of throttling structure parameters on the flow and cavitation characteristics of valves. In this paper, a combination of experimental and numerical simulations was used to study the effect of different structural parameters of valves on the flow coefficient. The results showed that increasing the flow channel inclination is beneficial to enlarging the flow coefficient. Meanwhile, the effects of different structural parameters on pressure and velocity of pressure reducing valves are discussed, the results indicated that increasing the inclination of the flow channel would reduce the vortex volume at the outlet. With the increase of the chamfer, the low-pressure area caused by the vortex in the near-wall surface decreases. Numerical simulations are conducted to investigate the effect of different structural parameters on the cavitation characteristics of valves. The numerical results showed that the flow channel inclination angle is 60° and the flow channel chamfer is less than 6 mm as the optimal value. In summary, considering the influence of structural parameters on flow coefficient, flow characteristics, and cavitation characteristics. The runner inclination angle is 60°, and the runner chamfer is 4 mm as the best value. The research work in this paper could provide technical support to achieve a better fluid pressure reducing and flow state of the TMSPRV under severe working conditions.

Numerical investigation on flow and atomization characteristics of hydrated magnesium nitrate gas-liquid two-fluid nozzle

The aim of this study is to reveal the atomization process of Mg(NO3)2·2H2O generated in the nitric acid leaching process of laterite nickel ore through a nozzle into a pilot pyrolysis furnace using CFD method. Based on the Euler-Lagrange method, a mathematical model of the hydrated magnesium nitrate gas-liquid two-fluid atomization nozzle was established, which can describe the gas-liquid flow characteristics. A visualization experimental platform was built for whose reliability has been verified by using graphical analysis technique. The influence law of gas channel inclination angle (hereinafter referred to as inclination angle), channel number and gas inlet pressure on the velocity inside the nozzle, liquid volume fraction and velocity and particle diameter of the atomization field were further explored. The results show that the number of gas channels is the main influencing factor for the average velocity at nozzle outlet and Sauter Mean Diameter (SMD) of atomized particles, while the gas inlet pressure mainly affects the volume fraction of liquid. When the inclination angle increases, the average velocity of nozzle outlet increases, and the Average Mean Diameter (AMD) and SMD of the atomized particles decrease. At the same time, the average volume fraction of hydrated magnesium nitrate first increased and then decreased, with the maximum value to 27.91% when the angle is 30°. Therefore, the high nozzle outlet velocity can play an important role in promoting droplet fragmentation and the volume fraction of hydrated magnesium nitrate for the later pyrolysis, only when the inclination angle is set properly.

Numerical assessment of the impact of transverse roughness ribs on the turbulent natural convection in a BIPV air channel

The effect of varying rib geometry on the turbulent natural convective heat transfer coefficient in a BIPV air channel was assessed numerically. The CFD model was validated with experimental data from the literature to within reasonable accuracy. The study investigated parameters such as the rib shape, dimensionless rib height (e/D), dimensionless rib pitch (p/e), and channel inclination angle (θ). In each case, the heat flux is varied from 100 W/m2 – 1000 W/m2. The natural convection heat transfer coefficient on the heated wall is maximized for a vertical channel with triangular rib of e/D = 0.16 and p/e = 8.84. The enhancement in heat transfer afforded by the transverse ribs translates to a reduction of the summer heat gain of up to 35.5%. The natural convection heat transfer coefficient correlates with Ras*(S/H), e/D, p/e and θ to within 15% error.

Flow and heat transfer of supercritical RP-3 kerosene in an inclined rectangular channel heated on one side

The flow and heat transfer of the supercritical RP-3 kerosene in inclined rectangular channel was investigated by a series of the three-dimensional numerical simulations. The inclined rectangular channel is only heated on the one side by the heat flux ranging from 500 kW/m2 to 640 kW/m2. The inclination angle of the rectangular channel varies from −90° to 90°. The results show that the evolution of the secondary flow along the main flow direction strongly depends on the inclination angle. In addition, the evolution of the secondary flow in vertical channels is much more complex than that in the inclined and horizontal ones. The average velocity of the secondary flow near the inlet of the heating section decreases with the increase of the inclination angle, while it increases firstly and then decreases after the inlet of the heating section with the increase of inclination angle. The secondary flow is enhanced by the increase of the heat flux. The severe thermal stratification always appears in the rectangular channels at all inclination angles. The minimum local heat transfer coefficient always appears near the walls at x = ±1 mm slightly after the inlet of the heating section, while the maximum one locates at x = 0 mm of the inlet of the heating section. The average heat transfer coefficient decreases first and then increases with the increase of heat flux and decrease of the inclination angle.

The technologies for the removal of coal technogenic deposits in the form of highly concentrated hydro mixtures

An analysis of the existing beneficiation coal waste storage facilities was carried out and ecologically friendly ways of lowering the water level and removing man-made deposits in the form of highly concentrated aqueous mixtures were carried out. The methodology for calculating the parameters and regimes of transportation for the man-made deposits waste with a high content of pollutants in the form of highly concentrated aqueous mixtures was developed. Models of the processes that occur during the extraction and transportation of man-made deposits in the form of highly concentrated aqueous mixtures were developed taking into account promising technologies. In case of an aqueous mixture with the significant initial tangential stress value, the transport of a highly concentrated aqueous mixture model along a vertical pipeline using a screw conveyor was developed. In this case, it is assumed that the aquous mixture will be lifted up at a height that ensures a nonpressure flow to the levee, where the aqueous mixture will be liquefied and its further transportation by pressure transport, vehicles or railway transport. The model of the process of the pressure flow of a highly concentrated aqueous mixture through the horizontal pipeline, depending on the transportation distance, provides for the use of centrifugal type pumps or piston pumps. Depending on the relative radius value for the undisturbed core of flow, the model takes into account the three most probable flow modes of highly concentrated aqueous mixtures through a circular cross-section pipeline and allows to perform both design and verification calculations. When the gravity force is used to transport a highly concentrated aqueous mixture to the shore, a mathematical model of nonpressure flow process of an aqueous mixture along an inclined channel with a rectangular cross-section was developed. This model takes into account the channel inclination angle, its width and the rheological parameters of the aqueous mixture and allows to calculate the geometric parameters of the channel, which are necessary to ensure the predefined transportation distance with the required flow rate. The results of the study could be applied for coal beneficiation waste storage facilities when they are out of maintenance, which will contribute to the elimination of technogenic impact on the environment, while for waste storage facilities that operate, appliance of the proposed technologies is a way of their size containing. Keywords: coal beneficiation waste storage, man-made deposits, highly concentrated aqueous mixtures.

Structured packing geometry study for liquid-phase mass transfer and hydrodynamic performance using CFD

An investigation on the geometry of structured packings was conducted using CFD to determine its impact on the liquid-phase hydrodynamic and mass transfer performance. Three variables validated the CFD hydrodynamic simulations: the liquid holdup, the liquid flow angle, and the Fanning friction factor. The hydrodynamic CFD predictions demonstrated excellent agreement with experimental holdup data, having a six percent average deviation. The CFD-predicted liquid mass transfer coefficient for the structured packing matched experimental data to within eight percent and also compared favorably with predictions from four industry-accepted semi-empirical correlations. To determine the dependence of the liquid-phase performance on the geometry of structured packings, the channel inclination angle and the channel opening angle varied. The liquid flow angle impacted the liquid mass transfer coefficient by increasing the upheaval as the film crossed each crimp in the structured packing.

Numerical Modeling of the Effects of Channel Configurations and Inclination Angles Inducing Buoyancy on Reverse Osmosis

Numerical Modeling of the Effects of Channel Configurations and Inclination Angles Inducing Buoyancy on Reverse Osmosis

CFD-based study on structured packing geometry

A computational fluid dynamics (CFD) based investigation of structured packing geometry was performed for gas phase hydrodynamic and mass transfer performance. The computational results were validated with experimental data with a robust mass transfer methodology for the gas-phase resistance identified through pipe flow simulations. The methodology was then applied to structured packing simulations for a variety of industrially relevant geometries. The mass transfer predictions agreed to within five percent of pilot-scale experimental data for standard commercial packings. The geometry of structured packing was studied by systematically changing the specific packing area, channel inclination angle, and channel opening angle to determine the geometry which produced a high degree of mass transfer or a low pressure drop.

The effect of the inclined lightning channel on electromagnetic fields and the induced voltages on overhead lines

In this study, the effect of lightning channel inclination on above-ground lightning electromagnetic (LEM) fields and their induced voltages on the overhead lines at different distances from stroke location (SL) in the presence of lossy soil ground is investigated. To this end, the finite element method is used to solve the full-wave Maxwell’s equations. The results show that channel inclinations affect LEM fields significantly at all distances from the SL. At an equal distance from SL, the observation point position relative to the lightning channel is important, and LEM fields of the points located on the horizontal axis of the lightning channel are affected more than other points. If the ground is more conductive, increasing channel inclination affects the radial component of the electric field at a close distance to the SL more; if the ground is more resistive, increasing channel inclination angle affects the radial component of the electric field at a far distance to SL more significantly. The vertical electric fields and azimuthal magnetic fields are slightly affected by ground conductivity but significantly affected by the position and channel inclination angle. Seven different states are considered for the channel position relative to the overhead line, and the lightning-induced voltage along the line is calculated at three points. The obtained results show that position and soil electrical parameters significantly affect the peak and wave shape of the induced voltage. If the lightning channel passes above the overhead line, the induced voltage peak will increase at points near the SL. If the horizontal axis of the lightning channel is parallel to the overhead line, the induced voltage peak will increase for the ground with lower conductivity by increasing the channel inclination angle. In this case, at distances farther from the SL, the effect of increasing the channel angle is negligible for high-conductivity grounds, but the induced voltage peak for less conductive grounds will increase. If the lightning channel's horizontal axis is perpendicular to the overhead line and the lightning channel does not pass above the overhead line, close to the SL, the induced voltage peak will decrease by increasing channel angle. At points far from the SL, increasing the channel angle in the low-conductivity ground will increase the voltage peak, and grounds with larger conductivity will decrease the voltage peak.

Effect of Channel Aspect Ratio and Inclination Angle on Flow and Mixing Performance of a Microdevice—A CFD Study

Effect of Channel Aspect Ratio and Inclination Angle on Flow and Mixing Performance of a Microdevice—A CFD Study

Two-phase model for mixed convection and flow enhancement of a nanofluid in an inclined channel patterned with heated slip stripes

PurposeThe purpose of this study is to analyze the heat transfer and flow enhancement of an Al2O3-water nanofluid filling an inclined channel whose lower wall is embedded with periodically placed discrete hydrophobic heat sources. Formation of a thin depletion layer of low viscosity over each hydrophobic heated patch leads to the velocity slip and temperature jump condition at the interface of the hydrophobic patch.Design/methodology/approachThe mixed convection of the nanofluid is analysed based on the two-phase non-homogeneous model. The governing equations are solved numerically through a control volume approach. A periodic boundary condition is adopted along the longitudinal direction of the modulated channel. A velocity slip and temperature jump condition are imposed along with the hydrophobic heated stripes. The paper has validated the present non-homogeneous model with existing experimental and numerical results for particular cases. The impact of temperature jump condition and slip velocity on the flow and thermal field of the nanofluid in mixed convection is analysed for a wide range of governing parameters, namely, Reynolds number (50 ≤ Re ≤ 150), Grashof number (), nanoparticle bulk volume fraction (5), nanoparticle diameter () and the angle of inclination ().FindingsThe presence of the thin depletion layer above the heated stripes reduces the heat transfer and augments the volume flow rate. Consideration of the nanofluid as a coolant enhances the rate of heat transfer, as well as the entropy generation and friction factor compared to the clear fluid. However, the rate of increment in heat transfer suppresses by a significant margin of the loss due to enhanced entropy generation and friction factor. Heat transfer performance of the channel diminishes as the channel inclination angle with the horizontal is increased. The paper has also compared the non-homogeneous model with the corresponding homogeneous model. In the non-homogeneous formulation, the nanoparticle distribution is directly affected by the slip conditions by virtue of the no-normal flux of nanoparticles on the slip planes. For this, the slip stripes augment the impact of nanoparticle volume fraction compared to the no-slip case.Originality/valueThis paper finds that the periodically arranged hydrophobic heat sources on the lower wall of the channel create a significant augmentation in the volume flow rate, which may be crucial to augment the transport process in mini- or micro-channels. This type of configuration has not been addressed in the existing literature.

A numerical study of the mixed convection around slanted-pin fins on a hot plate in vertical and inclined channels

The mixed-convective heat transfer of slanted-pin fins on an inclined hot surface was studied numerically under the laminar flow condition. The computational model was constructed using the periodic boundary conditions in the lateral direction of fins. Adopting the Boussinesq approximation, the three-dimensional governing equations for fluid flow and heat transfer were solved using the SIMPLE algorithm. The effects of fin-inclination angles in the range of -45o to +45o were investigated for the Richardson numbers ranging from 0.3–10, by changing the temperature of the hot plate. The effects of channel-inclination from 90o (vertical) to 0o (horizontal) were also investigated. In a vertical channel, it was found that as the buoyancy-driven flow increased, the thermal performance of the positively inclined fins became superior to the negatively inclined fins. However, in a horizontal channel, the thermal performance of the negatively inclined fins was superior for all the Richardson numbers. Details of the flow and heat transfer characteristics were summarized with respect to the channel-inclination angle in quantitative as well as qualitative ways. Difference in the heat transfer characteristic between the channel flow and open external flow was captured, which is important in the practical application.

Bubble diameters variation along the gas-liquid flow in a flat channel at various inclination angles

The results of an experimental study of a bubble diameters variation with a distance from the gas injection point in an upward bubbly flow in an inclined flat channel are presented. The measurements were carried out for a superficial liquid velocity of 0.51 m/s (Re = 12400) and various volumetric gas flow rate ratios. It is shown that at low values of volumetric gas flow rate ratio (β < 2 %), there is almost no bubble coalescence; therefore, the channel inclination angle and distance from the point of gas injection into the liquid flow do not affect the average diameter of gas bubbles.

Guided Air by Convection to Cool-Down Inclined Channel Supported by Two Heat Sources

This paper presents the numerical study of the laminar mixed-convection heat transfer of two identical protruding heat sources mounted in an inclined channel with obstacle. The control volume method and the SIMPLER algorithm are used to solve the dimensionless governing equations of mass, momentum, and energy for mixed convection. The effects of the obstacle, the channel inclination and the Reynolds number 5 ≤Re≤ 30 on streamlines and isotherms as well as on the heat transfer rate at the surface of each component are investigated for Pr=0.71 and Gr=105. The finding results show that for the channel inclination angle in the range 30° ≤φ≤60°, the obstacle has a large effect on the rate of transfer. In addition, by analyzing the effect of the obstacle size, it has been found out that the obstacle height has a strong effect on the cooling rate of the area between the two sources while the obstacle width effect is less noticeable.