Velocity Distribution Research Articles

Interaction of induced magnetic field, double diffusion convection and multiple slips for thermal radiative biological flow of six-constant Jeffreys nanofluid: Advancements in mechanics

ABSTRACT The mathematical modeling of biological fluids holds paramount importance, given its diverse applications in the medical field. Understanding the peristaltic mechanism is crucial for gaining insights into various biological flows. This study focuses on numerically estimating the double-diffusive peristaltic flow of a non-Newtonian six constant Jefferys nanofluid within an irregular medium. The investigation considers the influences of nonlinear thermal emission, viscous dissolution, and induced magnetization, incorporating multiple slip conditions. The Buongiorno model is employed to underscore key features related to thermophoresis and Brownian diffusion coefficients. The convection of double diffusivity is elucidated through the Soret and Dufour variables. Lubrication technique is employed for mathematical simulation, and the resulting nonlinear coupled system of differential equations is solved numerically through the Mathematica program’s built-in command (ND Solve function). The graphical representation of the impact of crucial flow variables, such as nanoparticle volume proportion, pressure gradient, solute density, temperature, pressure fluctuation per wavelength, and velocity distribution, provides valuable insight. The findings of the current study show that an increase in the Prandtl number and thermophoresis parameter leads to the expansion of thermal curves. Moreover, it is also noted that rising heat frequencies of radiation cause the concentration of nanoparticles to increase.

Slippage flow of second-grade fluid over a vertical plate with thermo-diffusion effect: an application of hybrid fractional operator

This research investigates the effects of slip and thermo-diffusion on magnetohydrodynamic fluid flow and heat transfer through a porous medium, using a fractional second-grade fluid model. A semi-analytical solution is obtained through Laplace transform techniques, revealing detailed insights into concentration, temperature, and velocity distributions. The study sheds light on the significant impact of key parameters, including Prandtl and Schmidt numbers, Grashof numbers, and the second-grade parameter, on the intricate relationships between thermo-diffusion, slip conditions, and fluid flow in porous media.

Slow molecular beams from a cryogenic buffer gas source

We study the properties of a cryogenic buffer gas source that uses a low-temperature two-stage buffer gas cell to produce very slow beams of ytterbium monofluoride molecules. The molecules are produced by laser ablation inside the cell and extracted into a beam by a flow of cold helium. We measure the flux and velocity distribution of the beam as a function of ablation energy, helium flow rate, cell temperature, and the size of the gap between the first and second stages of the cell. We also compare the velocity distributions from one-stage and two-stage cells. The one-stage cell emits a beam with a speed of about 82ms−1 and a translational temperature of 0.63 K. The slowest beams are obtained using the two-stage cell at the lowest achievable cell temperature of 1.8 K. This beam has a peak velocity of 56ms−1 and a flux of 9×109 ground-state molecules per steradian per pulse, with a substantial fraction at speeds below 40ms−1. These slow molecules can be decelerated further by radiation pressure slowing and then captured in a magneto-optical trap. Published by the American Physical Society 2024

A probability-constraint-based method based on the honey badger algorithm for wind estimation with coherent Doppler wind lidar

Coherent Doppler wind lidar (CDWL) has emerged as an effective tool for analyzing wind velocity distributions. It utilizes the peak frequency of the signal spectrum to determine wind velocity. However, accurate identification of the spectrum peak in low signal-to-noise ratio (SNR) environments is complicated by noise pollution. Enhancing CDWL performance involves correcting the spectrum in these challenging areas. Existing probability-constraint-based methods (PCBMs) require empirical parameter settings, limiting their adaptability across different Doppler wind lidar environments. This paper proposes and demonstrates a probability-constraint-based method based on the honey badger algorithm (PCBM-HBA). The gate moving average method (GMAM) based on the spectrum obtains the reference wind velocity as a constraint. The correlation coefficient between the inverted wind velocity value of PCBM and the reference wind velocity is used as the negative value of the fitness function to obtain the optimal parameter σ. Simulation results based on the American Standard Atmosphere Model show that PCBM-HBA can measure wind fields in areas with low SNRs, and the maximum detection range improves from 3.8 to 5.4 km. During the inversion of the measured signal, the PCBM-HBA improves the inversion results of wind velocity under different pulse conditions, and the inversion results of the PCBM-HBA with 50 accumulated pulses are better than those of the traditional method with 150 accumulated pulses, which enhances the applicability of the PCBM and improves the performance of the system.

Molecular dynamics simulation of heat and mass transfer in a nano-grooved heat pipe: Focusing on filling ratios' effect.

Managing the heat generated in microprocessors and other similar heat-generating devices requires the design and construction of superconductors with high reliability. For this purpose, heat pipes (HPs) are a very good option. Nano-grooved micro flat plate heat pipes (FPHPs), which are in the group of vapor chambers (VCs), have received attention due to their suitable structure. In this research, an FPHP with a length of 1050nm is investigated using molecular dynamics (MD) simulation. The effects of using three metals for walls including platinum (Pt), copper (Cu), and aluminum (Al) as well as three working fluids including argon (Ar), water (H2O), and ethanol (EtOH) were investigated. Focusing on the filling ratio of the interior space, mass and heat transfer inside the HP has been fully investigated. Evaporation rate, condensation rate, temperature, density, and velocity distribution as well as heat flux have been studied. The results show that although Ar shows better mass transfer results (due to its monoatomic nature), EtOH has better thermal performance. Among the three metals used, Cu has the best thermal performance. The maximum heat flux is obtained by using Cu and EtOH and is equal to 1819 W/cm2. The optimal filling ratio is reported in different states. The maximum mass transfer rate relates to Ar and at FR = 0.3; which equals 32.5%. The highest phase change rate is obtained using platinum and water, which is equal to 74%.

Particle size and settling velocity of bed and suspended sediments for mud-sand beds

The particle size and the settling velocity of sediments are key parameters in sediment transport studies. However, it remains surprisingly difficult to determine particle size and settling velocity distribution of fine-grained sediments (mud-sand). A large range of methodologies exist to measure either the particle size distribution or to measure the settling velocity. An important influential parameter is the shape of fine-grained sediments, with clay minerals being shaped as plates rather than as spheres. Furthermore, the settling velocity of fine particles is influenced by turbulent shear and flocculation processes. Sometimes, the sediment samples are pre-treated (destroying inter-particle bonds) to measure the primary particle sizes involved while in other cases samples are not pre-treated in order to represent the effect of flocs. As a result, a large uncertainty exists in the way particle size and settling velocity should be measured. A range of methodologies (sedimentation, video camera, and laser-diffraction) to measure the settling velocity and particle size distribution in the field and in the laboratory is used and compared. The labour-intensive sedimentation methods measure a particle size distribution which can be used for sedimentation studies. The particle size distribution measured by the most commonly applied laser diffraction method is representative of the plate diameter of the clay particles, but the corresponding settling velocity is not correct. This difference can be explained by the shape of the clay particles through a derivation of the settling velocity of non-spherical particles resulting in a simple relationship to convert the particle size measured by laser diffraction to a representative particle size to be used in sedimentation studies. A comparison of the settling velocity measured by an in situ settling method and by a video camera method shows good agreement for high concentrations (> 2000 mg/L) but deviating results for low concentrations (< 500 mg/L).

Equilibrium dynamical models in the inner region of the Large Magellanic Cloud based on Gaia DR3 kinematics

Context. The Large Magellanic Cloud (LMC) contains complex dynamics driven by both internal and external processes. The external forces are due to tidal interactions with the Small Magellanic Cloud and the Milky Way, while internally its dynamics mainly depend on the stellar, gas, and dark matter mass distributions. Despite this complexity, simple physical models often provide valuable insights into the primary driving factors. Aims. We used Gaia Data Release 3 (DR3) to explore how well equilibrium dynamical models based on the Jeans equations and the Schwarzschild orbit superposition method are able to describe the LMC’s five-dimensional phase-space distribution and line-of-sight (LOS) velocity distribution, respectively. In the Schwarzschild model, we incorporated a triaxial bar component for the first time and derived the LMC’s bar pattern speed. Methods. We fit comprehensive Jeans dynamical models to all Gaia DR3 stars with proper motion and LOS velocity measurements found in the footprint of the VISTA near-infrared survey of the Magellanic System using a discrete maximum likelihood approach. These models are very efficient at discriminating genuine LMC member stars from Milky Way foreground stars and background galaxies. They constrain the shape, orientation, and enclosed mass of the galaxy under the assumption of axisymmetry. We used the Jeans model results as a stepping stone to more complex two-component Schwarzschild models, which include an axisymmetric disc and a co-centric triaxial bar, which we fit to the LMC Gaia DR3 LOS velocity field using a χ2 minimisation approach. Results. The Jeans models describe the rotation and velocity dispersion of the LMC disc well, and we find an inclination angle of θ = 25.5° ±0.2°, line of nodes orientation of ψ = 124° ±0.4°, and an intrinsic thickness of the disc of q0d = b/a = 0.23 ± 0.01 (minor to major axis ratio). However, bound to axisymmetry, these models fail to properly describe the kinematics in the central region of the galaxy dominated by the LMC bar. We used the derived disc orientation and the Gaia DR3 density image of the LMC to obtain the intrinsic shape of the bar. Using these two components as input to our Schwarzschild models, we performed orbit integration and weighting in a rotating reference frame fixed to the bar, deriving an independent measurement of the LMC bar pattern speed of Ω = 11 ± 4 km s−1 kpc−1. Both the Jeans and Schwarzschild models predict the same enclosed mass distribution within a radius of 6.2 kpc of ∼ 1.4 × 1010 M⊙.

A pseudo-density conjugate heat transfer method and its application to simulating the quasi-steady temperature field of a compressor cylinder

The substantial disparity in time scales between heat conduction and convection requires extremely tiny time steps in simulations, leading to significant computational demands when using current-tightly coupled methods to solve the temperature field of cylinders at the quasi-steady stage. A new pseudo-density method is proposed to accelerate the heat conduction rate. The influence of solid density on transient temperature under the periodic third-type boundary conditions is analyzed in a one-dimensional model by analytical methods and verified in a three-dimensional structure by numerical methods. It is found that reducing solid density can accelerate the heat conduction rate and increase the fluctuation amplitude of solid temperature. Therefore, a variable pseudo density is adopted for solids in the simulation of the transient heat transfer characteristics between the compressed gas and the cylinder. The results show that the pseudo-density method provides similar computational accuracy to the current tightly coupled methods, but at significantly lower computational cost. The fluctuation amplitude of the cylinder's temperature decreases rapidly in the wall thickness direction. The distribution of the convective heat transfer coefficient on the inner wall of the cylinder is extremely transient and highly non-uniform, which is consistent with the distribution of gas velocity near the cylinder wall.

Study on simulated airflow dynamics of children with obstructive sleep apnea treated by different surgical methods

Objective:To analyze the effects of adenoidectomy, tonsillectomy and tonsillectomy combined with adenoidectomy on obstructive sleep apnea children by computational fluid dynamics numerical simulation. Methods:A case of typical tonsil with adenoid hypertrophy was selected. Mimics 21.0 software was used to establish the original preoperative model, adenoidectomy, tonsillectomy and virtual surgical models of tonsillectomy combined adenoidectomy, and the computational fluid dynamics model of the upper airway was established by ANSYS 2019 R1 software, and then the pressure and velocity of the internal flow field of the CFD model were numerically simulated. Seven planes perpendicular to the flow trace were selected as the observation planes, including the cross section of the sinusostoma complex, the anterior end of the adenoid body, the narrowest cross section of the nasopharyngeal cavity, the pharyngostoma tube, the narrowest cross section of the oropharyngeal cavity, the lower pole of the tonsil and the glottis section. The comparison indexes included pressure, flow velocity and flow distribution. Results:Compared with the original model before operation, after the adenoids were removed only, the pressure drop between the section of the ostiomeatal complex and the section of the eustachian tube decreased, the high velocity peak at the anterior end of the adenoids disappeared, and the flow trace through the middle nasal canal increased. When only bilateral tonsils were removed, the pressure drop between the eustachian tube and the glottis slowed down and the flow velocity between the eustachian tube and the glottis slowed down. Combined tonsillar-adenoidectomy resulted in the most uniform pressure distribution, the most gentle pressure change and flow rate in the upper airway, and the most ignificant increase in airflow trace through the middle nasal canal among the three operations. Conclusion:Adenoidectomy, tonsillectomy and combined tonsillar adenoidectomy can make the airflow velocity and pressure of upper respiratory tract uniform to different degrees, but there are obvious differences in the specific anatomical location and degree. The application of CFD can intuitively predict the improvement of upper airway flow field in OSA children by different surgical methods, which helps clinicians to make surgical decision.

Numerical study of Mg(OH)2/MgO thermochemical heat storage reactor coupled with parabolic dish solar system

Systems coupling Mg(OH)2/MgO thermochemical reactor with parabolic dish solar collector (PDSC) have a potential application prospect in solar seasonal heat storage. However, their working mechanism has not been systematically studied and not well understood either. In this study, Mg(OH)2-based thermochemical reactor, which was coupled with PDSC, was numerically studied for the first time using a three-dimensional model. The various working conditions and influencing factors of PDSC system were investigated, and a comprehensive analysis and optimization for the heat storage performance of the reactor such as the reaction time and energy storage rate were conducted. Effects of the fluid inflow temperature, velocity, and fluid pipe distribution on heat storage performance were also unfolded. For instance, when the heating pipe was arranged at 70 mm from the central axis, the reaction time was 15.9 % less than that of evenly arranged at R/2 from the center. Moreover, fins were added to the reactor and the fin shape was optimized using the density-based topology optimization method. It was found that the reaction time was reduced by 42.4 % and was only 12614 s.

Entropy Analysis in Magnetized Blood-Based Hybrid Nanofluid Flow via Parallel Disks

Magnetized hybrid nanofluid combined with ferrite and silver in a blood-based liquid presents their vital role in several aspects such as artificial heart pumping system, drug delivery process, the flow of blood in the artery, etc. This is because the high heat transportation rate of the nanofluid is caused by the inclusion of nanoparticles. The current investigation is based on the characteristic of particle concentration comprised of Fe3O4 and Ag in the base liquid blood that passed in between two infinite parallel disks filled with porous matrix. The electrically conducting fluid associated to maximum of 1.5% of volume concentration from each of the solid particles affects the flow phenomena. However, the impact of thermal radiation vis-à-vis the heat dissipation provides efficient heat transport properties with the inclusion of the effective thermal conductivity assumed from the Hamilton-Crosser model. The proposed conductivity model describes the role of particle shapes on the enhanced thermal properties. Further, numerical treatment is obtained for the transformed designed problem following similarity rules that are used for the conversion of the governing equations into their non-dimensional form. The computation of various flow profiles leads to get the entropy generation due to the irreversibility processes. Along with the fluid velocity and temperature distributions, the study is carried out for the entropy as well as the computation of Bejan number and afterwards the simulation of the shear and heat transportation rate are also depicted graphically. The main finding of the proposed study is that solid particle concentrations have a substantial impact to increasing fluid velocity in magnitude, resulting in a narrower wall thickness at both channel walls. Thermal radiation was shown to be more effective at increasing entropy generation and Bejan value.

Inertial aftermaths on peristaltic drive of MHD micropolar fluid in a two-dimensional asymmetric inclined porous soaked channel independent of wavelength: Galerkin finite element simulation

This manuscript presents a detailed investigation of the peristaltic propulsion of a micropolar fluid in an inclined asymmetric channel, which is also subjected to a magnetic field applied in the normal direction. The medium is considered to be a porous, saturated environment. Unlike traditional lubrication theory, which often assumes long wavelengths and negligible Reynolds numbers, our analysis does not adhere to these constraints. This approach introduces nonlinearity into the modeled equations and allows for significant Reynolds numbers, thereby enhancing our understanding of the peristaltic phenomenon. Numerical solution of coupled partial differential equations is gained by employing a novel Galerkin built finite element method and is presented through graphs of velocity and pressure distributions in accordance with variation in several flow parameters. Streamlines’ gyration, microrotation, and vorticity for different configurations that emerged with varying phase transitions are displayed in this regard as well. It is confessed that peristaltic mixing diminishes for all values of phase differences as the permeability parameter increases, while a rising Hartmann number significantly exacerbates this effect. In addition, the microrotation of micropolar particles is observed to become increasingly distorted with higher Reynolds numbers. Furthermore, the pressure rise throughout both pumping and co-pumping regions is enhanced when the inclined channel is subjected to a greater angle of inclination.

Inertial active Ornstein–Uhlenbeck particle in a non-linear velocity dependent friction

We explore the self-propulsion of an active Ornstein–Uhlenbeck particle with a non-linear velocity dependent friction. Using analytical approach and numerical simulation, we have exactly investigated the dynamical behaviour of the particle in terms of particle trajectory, position and velocity distribution functions in both underdamped as well as overdamped regimes of the dynamics. Analyzing the distribution functions, we observe that for a confined harmonic particle, with an increase in duration of self-propulsion, the inertial particle prefers to accumulate near the boundary of the confinement rather than the mean position, reflecting an activity induced bistability in the presence of nonlinear friction. On the other hand, in the overdamped or highly viscous regime, where the inertial influence is negligible, the sharp peak structure in the distribution across the mean position of the well reveals as usual trapping of the particle with increase in the persistent duration of activity. Moreover, for a free particle, using perturbation method, we have analytically computed the velocity distribution function in the vanishing limit of noise. The distribution interestingly shows the similar attributes as in case of a harmonic well, thus providing an additional effective confining mechanism that can be explained as a decreasing function of effective temperature. In this limit, the analytically computed distribution agrees well with the simulation results.

Synergistic influence of gyrotactic microorganisms and bimolecular reaction on bidirectional tangent hyperbolic fluid with Nield boundary conditions: A biomathematical model

In biomedical engineering, the behaviour of gyrotactic microorganisms with non-Newtonian fluids such as tangent hyperbolic fluids improve the design of targeted drug delivery systems. In this system control over microorganism movement is essential. The present study deals with the synergistic influence of gyrotactic microorganisms and bimolecular reactions on the bidirectional flow of tangent hyperbolic fluids under Nield boundary conditions. Further, the flow characteristic of the non-Newtonian fluid is enhanced by incorporating the impact of thermal radiation, heat sources, Brownian motion, and thermophoresis. The presentation of these phenomena is vital for an extensive range of applications, including industrial processes, biomedical engineering, and environmental management. The analysis employs advanced mathematical modelling which needs suitable transformation rules to get the non-dimensional form and further numerical simulation is presented with the assistance of the “shooting-based fourth-order Runge-Kutta technique”. The results are depicted for the several contributing factors via the built-in in-house function bvp4c in “MATLAB”. The authentication of the study with the prior research is a benchmark to precede further research in this direction. However, the outstanding results are; the fluid velocity is controlled by increasing non-Newtonian Weissenberg number whereas the velocity slip shows dual characteristics on the axial velocity distribution. Further, the motile microorganism profile is controlled by the enhanced bioconvection Lewis number.

Suppression and excitation by collisions of two-stream and bump-on-tail instabilities

Two-stream (TS) and bump-on-tail (BOT) electron distributions in plasma can lead to electrostatic instabilities and turbulence, and they have been extensively studied. Collisions usually mitigate these instabilities since they tend to hinder the motion of the participating electrons. Here, we numerically solve the full Vlasov–Poisson equations with Krook collisions to reconsider the evolution of the TS and BOT instabilities. It is found that even in the stable parameter regime predicted by linear theory, during the initial evolution (i.e., damping) stage, collisions can excite the TS instability. The reason is that during the evolution, efficient Krook collisions cause rapid thermalization of the TS electrons, leading to broadening of the initial velocity distributions of the two beams and appearance of regimes with unstable velocity gradients and trapped electrons. On the contrary, such a behavior does not occur for the BOT instability.

Direct simulations of bedrock core and cuttings transport phenomena in reverse circulation drilling

Polar drilling is essential for obtaining ice and bedrock samples, providing critical insights into climate and geological history. The reverse circulation drilling method, utilizing a dual-wall drill pipe, presents a stable and efficient strategy. Nonetheless, the intricate dynamics involving drilling fluids, rock cuttings and cores necessitate sophisticated modeling to elucidate the underlying mechanism and optimize drilling efficiency. To address this, we developed a multiphase flow model that accounts for non-Newtonian fluid behavior, turbulence, particle dynamics, and fluid–structure interactions, enabling a thorough assessment of various operational parameters. The model's temporal–spatial sensitivity was evaluated, and its accuracy was confirmed by comparison with three different sets of experimental data. A detailed parametric investigation was then conducted to systematically assess the effects of various parameters, including the non-Newtonian behavior and inlet velocity of the drilling fluid, the rate of penetration, and the dimensions of the cuttings and core. The simulation results indicate that the non-Newtonian behavior of the drilling fluid has an non-negligible effect on the transport efficiency of both cuttings and core. An increase in the fluid inlet velocity leads to faster transport, albeit at the cost of higher pump pressure. The rate of penetration has a minor influence on the core transportation but largely affects the cutting transportation. More interestingly, larger cuttings demonstrate enhanced transport efficiency, attributed to a more uniform velocity distribution. Furthermore, the core diameter plays a pivotal role in transport efficiency by significantly altering the fluid dynamics, whereas the core length has a negligible effect. These results may have direct applications for optimizing polar drilling operations, potentially leading to enhanced drilling efficiency, reduced drilling costs, and informing future drilling technology advancements.

A simplified method for estimating the alpha coefficient in surface velocity based river discharge measurements

Remote sensing techniques for river monitoring facilitate faster measurement campaigns compared to traditional methods, reduce risks to personnel and instruments, and allow measurements under critical flow conditions. An alpha coefficient (α) is commonly employed to convert surface velocities, obtained by contactless techniques, into depth-averaged velocities, which are used for the application of the velocity-area method for assessing discharge. Some optical-based software programs use a constant α value, based on a theoretical “standard”. However, analyses of empirical vertical velocity profiles in real cases reveal that α can significantly deviate from this standard due to various factors (roughness, turbulence, etc.).This study analyzes several ADCP (Acoustic Doppler Current Profiler)-based measurements in Sicily, Italy, to explore factors influencing flow velocity distribution and potential errors from using the standard α for discharge estimation via surface velocity-based methods. The results confirmed substantial variability in α, which is functionally related to some geometric factors characterizing the cross-section shape and the specific vertical where the velocity profile is computed. The generated dataset of empirical α values is also used to implement an Artificial Neural Network (ANN), offering a straightforward tool suitable for non-contact techniques. The ANN predicts α at any vertical of a measurement transect as a function of variables however necessary for discharge assessment by non-intrusive methods, leading to depth-averaged velocity estimates from surface velocities that are more accurate than those derived from conventional approaches, as demonstrated by four test cases.

Investigation of the flow characteristics and NOx formation mechanism of hydrogen micromix diffusion combustion with vortex generator

It is well established that hydrogen has become one of the most promising fuels for achieving zero-carbon emissions. However, hydrogen combustion still faces many challenges, particularly the flashback issue and high NOx emissions, which necessitate the exploration of hydrogen combustion technologies and pollution control measures. This paper proposes a micromix diffusion combustion scheme with a disturbance vortex generator (DVG). The flow characteristics of the micromix element were analyzed, including the velocity distribution, penetration depth, jet vortex length, and vortex structure. It was found that DVG would create an air streamwise vortex within the main airflow, thus accelerating the axial velocity decay and facilitating the penetration of hydrogen. The hydrogen jet vortex rolls up the mainstream air, forming a coupled vortex system, which further enhances mixing. Sensitivity analysis was carried out to study the influences of the key parameters of the micromix element. The hydrogen injection hole diameter and the DVG height were found to be the most influential factors. The interactions between vortex, flame, and NOx were investigated to obtain the mechanism of NOx formation. By conducting a comparative analysis of the effects of the hydrogen orifice diameter and the vortex generator height, it has been observed that augmenting the length of the jet vortex can significantly promote the mixing of hydrogen with the mainstream air, playing an essential role in reducing emissions. This study establishes a solid foundation for future research endeavors in the development of micromix diffusion combustors.

The Influence of Non-Pressure Pipes Filled to Different Degrees on the Hydraulic Characteristics of Channel–Pipe Combined Irrigation Systems

Modern irrigation areas often use a combination of channels and pipes for irrigation. Due to changes in terrain, inflow, and pipe diameter, pipelines are often prone to experiencing a state of no pressure. This lack of pressure affects not only the velocity distribution and water surface profile of the main channel but also the velocity distribution and flow distribution of the pipeline. Therefore, in this study, we employed a combination of physical model experiments and theoretical analysis to study the influence of non-pressure pipelines on the hydraulic characteristics of channel–pipe combined irrigation systems filled to different degrees. Through this, the variation laws of the flow velocity distribution, turbulence intensity, water surface, diversion width, and diversion ratio under different filling degrees were obtained. The non-pressure pipeline flow velocity expression was obtained through dimensional analysis, and the calculation formula for the non-pressure pipeline flow velocity coefficient was fitted using linear regression analysis. The relative error between the calculated value and the measured value did not exceed 8.81%. The research results presented in this article can provide technical support for the design and maintenance of channel–pipe combined irrigation systems.

Real-Time Environmental Design Parameters and their Impact on the Performance of Passive Basin Solar Still: A Dynamic CFD Modeling Approach

A computational fluid dynamics (CFD) approach was used in this work to investigate various design and environmental factors and their impact on the performance of passive basin solar stills (PBSS). This requires using the ANSYS software to build a sophisticated geometrical solar still model with the associated solar cells. The impact of solar cell configuration on energy optimization was determined by analyzing the developed system in both series and parallel configurations. Accuracy of simulation results was ensured in the model by introducing a meshing technique that consisted of&gt;2 million components. The results (for static pressure analysis) indicated the absence of any high-pressure-induced strains after evaluating the performance metrics (static pressure, velocity, and energy distribution) for impact on the system using &gt; 200 iterations; this suggests that the system design is balanced. Hence, the performance of solar stills can be improved by using new materials and design configurations as shown in this work. This study has improved knowledge of solar water desalination and other forms of renewable energy sources for related applications.