Analysis of the airflow features and ventilation efficiency of an Ultra-Clean-Air operating theatre by qDNS simulations and experimental validation.

Ultra-Clean-Air (UCA) operating theatres aim to minimise surgical instrument contamination and wound infection through high flow rates of ultra-clean air, reducing the presence of Microbe Carrying Particles (MCPs). This study investigates the airflow patterns and ventilation characteristics of a UCA operating theatre (OT) under standard ventilation system operating conditions, considering both empty and partially occupied scenarios. Utilising a precise computational model, quasi-Direct Numerical Simulations (qDNS) were conducted to delineate flow velocity profiles, energy spectra, distributions of turbulent kinetic energy, energy dissipation rate, local Kolmogorov scales, and pressure-based coherent structures. These results were also complemented by a tracer gas decay analysis following ASHRAE standard guidelines. Simulations showed that contrary to the intended laminar regime, the OT's geometry inherently fosters a predominantly turbulent airflow, sustained until evacuation through the exhaust vents, and facilitating recirculation zones irrespective of occupancy level. Notably, the occupied scenario demonstrated superior ventilation efficiency, a phenomenon attributed to enhanced kinetic energy induced by the additional obstructions. The findings underscore the critical role of UCA-OT design in mitigating MCP dissemination, highlighting the potential to augment the design to optimise airflow across a broader theatre spectrum, thereby diminishing recirculation zones and consequently reducing the propensity for Surgical Site Infections (SSIs). The study advocates for design refinements to harness the turbulent dynamics beneficially, steering towards a safer surgical environment.

Settling velocity of microplastics in turbulent open-channel flow.

The settling behavior of microplastics (MPs) plays a pivotal role in their transport and fate in aquatic environments, but the dominant mechanisms and physics governing the settling of MPs in rivers remain poorly understood. To gain mechanistic insights into the velocity lag of MPs in an open-channel flume under different turbulent flow conditions, an experimental study was conducted using three types of MPs: polystyrene, cellulose acetate, and acrylic, of sphere-shaped particles with diameters ranging from 1 mm to 5 mm. A particle tracking technique was employed to record and analyze the MPs velocity within turbulent flows. The results showed a variation in the vertical settling velocity of MPs ωMP ranging from -26 % to +16 %, when compared to their counterparts in still water (ωs). A new formula for the drag coefficient (Cd) of MP particles was developed by introducing the suspension number (u∗/ωs). The developed Cd formula was used to calculate the resultant velocity lag VMP, with a mean relative error of 16 % compared with the measured values. Further, the study highlighted that the MPs with large Stokes numbers are mainly driven by their own inertia and turbulence has less influence on their settling behavior. This study is crucial for understanding the settling behavior of MPs in turbulent flows and developing their transport and fate models for MPs in riverine systems.

Study on influence of turbulence intensity on blade airfoil icing mass & aerodynamic performance.

Wind is an emerging renewable energy resource, but more useful in cold regions. With the increasing threat of climate change and global warming, the unpredictability of wind energy patterns has been affected. With continual threats from extremes and uncertainties, icing on wind turbines has been noted to grow affecting aerodynamic performance. The effect of turbulence intensity at its impact on aerodynamic performance was numerically done using ANSYS Fluent and FENSAP ICE software. Conditions considered for the study included turbulence intensities, median volume diameter (MVD), liquid water content (LWC), angle of attack, and ambient temperature for 180 min. The study's conditions aimed at providing a wide range of effects covering the in-cloud icing and freezing drizzle. The mass of ice increased with an increase in LWC when it increased from 0.05 g/m3 to 0.3 g/m3, and MVD with 1000 µm compared to 40 µm, but when temperature decreased led to an increase from -1 °C to -15 °C. Increasing the angle of attack led to reduced aerodynamic performance with stall angle occurring at α = 0-18°. An increase in the turbulence intensity from 0.01 % to 50 % resulted in decreased CL/CD.

Introducing a Novel Innovative Technique for the Recording and Interpretation of Dynamic Coronary Angiography.

In the study of coronary artery disease (CAD), the mechanism of plaque formation and development is still an important subject for investigation. A limitation of current coronary angiography (CAG) is that it can only show static images of the narrowing of arterial channels without identifying the mechanism of the disease or predicting its progression or regression. To address this limitation, the CAG technique has been modified. The new approach emphasizes identifying and analyzing blood flow patterns, employing methodologies akin to those used by hydraulic engineers for fluid or gas movement through domestic or industrial pipes and pumps. With the new technique, various flow patterns and arterial phenomena-such as laminar, turbulent, antegrade, retrograde, and recirculating flow and potentially water hammer shock and vortex formation-are identified, recorded, and classified. These phenomena are then correlated with the presence of lesions at different locations within the coronary vasculature. The formation and growth of these lesions are explained from the perspective of fluid mechanics. As the pathophysiology of CAD and other cardiovascular conditions becomes clearer, new medical, surgical, and interventional treatments could be developed to reverse abnormal coronary flow dynamics and restore laminar flow, leading to improved clinical outcomes.

Enhancing the implantation of mechanical circulatory support devices using computational simulations.

Introduction: Patients with end-stage heart failure (HF) may need mechanical circulatory support such as a left ventricular assist device (LVAD). However, there are a range of complications associated with LVAD including aortic regurgitation (AR) and thrombus formation. This study assesses whether the risk of developing aortic conditions can be minimised by optimising LVAD implantation technique. Methods: In this work, we evaluate the aortic flow patterns produced under different geometrical parameters for the anastomosis of the outflow graft (OG) to the aorta using computational fluid dynamics (CFD). A three-dimensional aortic model is created and the HeartMate III OG positioning is simulated by modifying (i) the distance from the anatomic ventriculo-arterial junction (AVJ) to the OG, (ii) the cardinal position around the aorta, and (iii) the angle between the aorta and the OG. The continuous LVAD flow and the remnant native cardiac cycle are used as inlet boundaries and the three-element Windkessel model is applied at the pressure outlets. Results: The analysis quantifies the impact of OG positioning on different haemodynamic parameters, including velocity, wall shear stress (WSS), pressure, vorticity and turbulent kinetic energy (TKE). We find that WSS on the aortic root (AoR) is around two times lower when the OG is attached to the coronal side of the aorta using an angle of 45° ± 10° at a distance of 55 mm. Discussion: The results show that the OG placement may significantly influence the haemodynamic patterns, demonstrating the potential application of CFD for optimising OG positioning to minimise the risk of cardiovascular complications after LVAD implantation.

Microplastic infiltration into mobile sediments.

This study investigates the dynamics of microplastic infiltration into non-stationary sandy sediments, a pressing environmental concern due to the rising prevalence of microplastics in aquatic ecosystems. An annular flume was used to simulate riverine bedform motion, examining the suspension and infiltration of denser-than-water microplastic particles, including polyvinyl chloride (PVC), polyamide (PA), and polylactide (PLA). The experiments focused on various particle sizes (ranging from 0.2 to 5 mm in diameter) and bedform migration speeds, known as celerities. The findings indicate that particle size is a significant factor influencing the depth of infiltration and distribution within sediment layers, whereas the impact of bedform celerities and particle densities appears less significant. This research provides novel insights into the behavior of microplastics in dynamic sedimentary environments, highlighting the intricate interaction between microplastic characteristics and sedimentary processes. The results contribute to an enhanced understanding of microplastic distribution and accumulation in riverine systems, offering crucial data for developing predictive models and formulating potential remediation strategies for microplastic pollution.

Comparative predictions of turbulent non-isothermal flow of a viscoplastic fluid with yield stress.

RANS simulation of turbulent non-isothermal flow in a pipe by transition of Newtonian fluid into a viscoplastic non-Newtonian fluid is carried out. Carrier phase turbulence was modeled using two-equation isotropic k‒ε˜ - model and Reynolds stress transport model. Results of calculations of Newtonian and non-Newtonian power-law fluids were compared with data of DNS calculations of other authors. Comparisons with data from other works for isothermal Schwedoff-Bingham fluid were performed in this work using k‒ε˜ - model. Satisfactory agreement was obtained with data from other studies for the axial averaged velocity and turbulent kinetic energy radial profiles (the difference is up to 15 %). Reynolds stress transport model showed significant anisotropy between streamwise and transverse velocity fluctuations (up to several times) and good agreement with DNS results of other authors. Averaged and pulsation profiles express the indicated transformation of the non-isothermal turbulent flow.

Simultaneous determination of oxacillin and cloxacillin in plasma and CSF using turbulent flow liquid chromatography coupled to high-resolution mass spectrometry: Application in therapeutic drug monitoring.

Cloxacillin and oxacillin are group M penicillins. The therapeutic monitoring of plasma concentrations of these antibiotics and those of their hydroxymethylated metabolites is of great clinical interest, especially in the choice of an adequate dosage allowing an effective treatment while limiting the occurrence of undesirable effects and the development of bacterial resistance. In this context, we conducted this work aiming at developing and validating a method allowing the determination of cloxacillin and oxacillin as well as the identification of their active metabolites in different biological matrices (CSF and plasma) using turbulent flow liquid chromatography coupled to high-resolution mass spectrometry. To do this, we carried out several optimisation tests. Subsequently, we validated our method according to the latest bioanalytical validation recommendations of the European Medicines Agency. The validation results showed that our method is specific and sensitive. We obtained good linearity in the range 0.5 to 100 µg/mL with correlation coefficients above 0.995. The lower limit of quantification was 0.5 µg/mL for each analyte. The method was found to be accurate with repeatability and reproducibility coefficients of variation below 15 %. Our method is also accurate with bias values below 15 %. Recovery values ranged from 87 % to 95 %. Finally, we were able to apply our method to the therapeutic monitoring of the analysed molecules and to identify their active metabolites. Our results suggest that LC-MS shows superiority in the therapeutic monitoring of these antibiotics due to the superiority of specificity shown by this method. This assay method can be routinely used for the daily plasma assays of patients treated with these antibiotics in the context of therapeutic monitoring.

[Application progress of on-line sample preparation techniques coupled with liquid chromatography-mass spectrometry system in the detection of food hazards].

Food safety has received increased attention, and food detection is of great significance. The food matrix is complex, and diverse food hazards have been identified. Thus, the detection methods and sample preparation techniques for food matrices must be continuously optimized and updated. Several steps are usually required when a chromatographic system is used to determine food hazards: sample preparation, that is, the separation of targets from different substrates using a suitable preprocessing method and target-substance separation and purification, which is usually achieved using chromatographic separation. The selection of an appropriate detector for qualitative and quantitative analyses is usually based on the properties of the target compound. The sample preparation procedure is considered the most time-consuming aspect of the entire food-analysis process. It is also prone to analytical errors. Therefore, optimization of the sample preparation process is a key issue in the field of chemical analysis. Researchers have developed a series of new, efficient, and accurate sample preprocessing methods, and an on-line sample-preparation system has been found to be a feasible approach. On-line sample preparation coupled with liquid chromatography-mass spectrometry (LC-MS) presents many advantages. First, manual operation could reduce analytical errors to ensure good accuracy and repeatability. It could also reduce the consumption of chemical reagents and avoid cross-contamination between samples. Furthermore, an on-line sample-preparation system could shorten the sample-preparation time and improve the detection efficiency. On-line sample preparation coupled with LC-MS has been widely applied in the fields of environment, biology, and food. On-line sample preparation systems coupled with LC-MS are divided into two modules: the first modules involves sample preparation and the second module involves the LC system. The first module remove impurities and isolates the target compounds in preparation for their qualitative and quantitative detection. The coupling of these two modules depends mainly on valve switching. In this paper, we introduce the most frequently used on-line sample-preparation techniques, including on-line solid phase extraction (on-line SPE), in-tube solid phase microextraction (in-tube SPME), and turbulent chromatography (TFC). We then describe the basic principles and coupling equipment of these three on-line analytical technologies in detail. The coupling equipment establishes a physical connection between the two modules. Next, we discuss the properties of different purification fillers in an on-line sample-preparation column. The applications and research progress of on-line systems for pesticide residues, veterinary drug residues, and biotoxins are also discussed. Compared with offline sample preparation, on-line analytical systems present several advantages. On-line analytical systems can not only greatly reduce the analysis time and solvent consumption but also improve the detection sensitivity and accuracy. Such systems can be used to determine food hazards to ensure food safety. Finally, the existing problems and development trends of on-line analytical systems are discussed and prospected. To promote the applications of on-line analytical technology in food-safety detection, we suggest that the following three aspects be considered. First, more on-line purification columns with novel fillers, in addition to C18 or polymer fillers, should be developed. Second, compared with ordinary detectors, high-resolution MS detectors have better precision and accuracy. Coupling on-line analytical technologies with a high-resolution mass spectrometer may be beneficial for the further development of on-line analyses. Third, different food matrices should be compared and evaluated to continuously optimize the detection process and improve the efficiency of on-line analytical systems. As concerns regarding food safety issues have increased, the applications of on-line analytical technologies for food detection can be expected to become increasingly important.

Effects of near-bed turbulence on microplastics fate and transport in streams.

Quantifying the impact of hyporheic exchange is crucial for understanding the transport and fate of microplastics in streams. In this study, we conducted several Computational Fluid Dynamics (CFD) simulations to investigate near-bed turbulence and analyze vertical hyporheic exchange. Different arranged spheres were used to represent rough and permeable sediment beds in natural rivers. The velocities associated with vertical hyporheic flux and the gravitational force were compared to quantify the susceptibility of microplastics to hyporheic exchange. Four scenario cases representing different channel characteristics were studied and their effects on microplastics movements through hyporheic exchange were quantitatively studied. Results show that hyporheic exchange flow can significantly influence the fate and transport of microplastics of small and light-weighted microplastics. Under certain conditions, hyporheic exchange flow can dominate the behavior of microplastics with sizes up to around 800 µm. This dominance is particularly evident near the sediment-water interface, especially at the top layer of sediments. Higher bed porosity enhances the exchange of microplastics between water and sediment, while increased flow conditions extend the vertical exchange zone into deeper layers of the bed. Changes in the bedform lead to the most pronounced vertical hyporheic exchange, emphasizing the control of morphological features on microplastics transport. Furthermore, it is found that sweep-ejection events are prevailing near the bed surface, serving as a mechanism for microplastics transport in rivers. As moving from the water column to deeper layers in the sediment bed, there's a shift from sweeps dominance to ejections dominance, indicating changes of direction in microplastics movement at different locations.

Aggregation behavior of polyethylene microplastics in the nearshore environment: The role of particle size, environmental condition and turbulent flow.

Estuary and coastal waters are hotspot areas for microplastics (MPs) pollution. MPs of varying sizes converge in this complex nearshore environment. Aggregation is an important process that affects the transport and fate of MPs in the aqueous environment. Nevertheless, the influence of different factors on the aggregation behavior and the aggregates structure of MPs is unclear. In this study, the aggregation behavior and the aggregates structure of polyethylene microplastics (PEs) of different sizes under the impact of nearshore environmental conditions (i.e., salinity gradient, dissolved organic matter-DOM, turbulent flow) were investigated. The results show that particle size was the dominant factor affecting the stability of PEs in the aqueous environment, and the critical coagulation concentration (CCC) of PEs shifts to the right with increasing size. It was also found that the size of PEs stable aggregates is negatively correlated with the turbulent kinetic energy dissipation rate. The particle size of PEs can significantly affect the fractal dimension (FD) of stable aggregates, and the smaller the particle size, the more compact the aggregates formed. Moreover, salinity and DOM control the size and FD of PEs stable aggregates through different mechanisms. The findings of this study will be helpful for the prediction of the transport and fate of MPs in the aqueous environment.

Random Walk Particle Tracking to Model Dispersion in Steady Laminar and Turbulent Pipe Flow.

To accurately model a two-dimensional solute transport in drinking water pipes and determine the effective dispersion coefficients for one-dimensional water quality models of water distribution systems, a random walk particle tracking approach was developed to analyze the advection and dispersion processes in circular pipes. The approach considers a solute particle's two-dimensional random movement caused by molecular or turbulent diffusion and associated velocity profile, and can simulate any mixing time and accurately model the longitudinal distribution of the solute concentration. For long mixing times, the simulation results agreed with a previous analytically derived solution. For turbulent flow conditions, simulations showed that the longitudinal dispersion of the solute is very sensitive to the utilized cross-sectional velocity profiles. This approach is easy to implement programmatically and unconditionally stable. It can predict the mixing characteristics of a pipe under various initial and boundary conditions.

Tuning heat transport via coherent structure manipulation: recent advances in thermal turbulence.

Tuning transport properties through the manipulation of elementary structures has achieved great success in many areas, such as condensed matter physics. However, the ability to manipulate coherent structures in turbulent flows is much less explored. This article reviews a recently discovered mechanism of tuning turbulent heat transport via coherent structure manipulation. We first show how this mechanism can be realized by applying simple geometrical confinement to a classical thermally driven turbulence, which leads to the condensation of elementary coherent structures and significant heat-transport enhancement, despite the resultant slower flow. Some potential applications of this new paradigm in passive heat management are also discussed. We then explain how the heat transport behaviors in seemingly different turbulence systems can be understood by this unified framework of coherent structure manipulation. Several future directions in this research area are also outlined.

On the dispersion of a light chemical agent in a semi-closed environment. A theoretical study.

Chemical events have significant public health and emergency preparedness consequences; therefore, crisis response planning is of outmost importance. The dispersion of a chemical agent in an indoor environment, near the so-called "human breathing zone" can cause harmful effects to its occupants. The present study examines the dispersion of ammonia (NH3), i.e., a lighter than air, colorless, highly irritating gas with a suffocating odor, in an office. For that, the turbulent flow of NH3 under the influence of the indoor air's circulation has been simulated, using a Computational Fluid Dynamics model, i.e., the Realizable k-e model. On the whole, the study provides estimation and of the NH3 levels in the office, mainly up to the human breathing zone, as well as evaluation of the natural ventilation's contribution in the decongestion and decontamination of indoor air.•The 3D geometric model of the office was created, taking under consideration the office's structure, the equipment's layout, the openings' positions as well as any other object that could act as an obstacle to the agent's flow.•The domain's 3D Computational Mesh was created and grid independence tests were performed, in order to secure the solution's independence from the grid.•The chemical agent's flow was simulated and the results were compared to the IDLH index and the AEGLs set for ammonia.

Impact of human body shape on forced convection heat transfer.

Predicting human thermal comfort and safety requires quantitative knowledge of the convective heat transfer between the body and its surrounding. So far, convective heat transfer coefficient correlations have been based only upon measurements or simulations of the average body shape of an adult. To address this knowledge gap, here we quantify the impact of adult human body shape on forced convection. To do this, we generated fifty three-dimensional human body meshes covering 1st to 99th percentile variation in height and body mass index (BMI) of the USA adult population. We developed a coupled turbulent flow and convective heat transfer simulation and benchmarked it in the 0.5 to 2.5 m·s-1 air speed range against prior literature. We computed the overall heat transfer coefficients, hoverall, for the manikins for representative airflow with 2 m·s-1 uniform speed and 5% turbulence intensity. We found that hoverall varied only between 19.9 and 23.2 W·m-2 K-1. Within this small range, the height of the manikins had negligible impact while an increase in the BMI led to a nearly linear decrease of the hoverall. Evaluation of the local coefficients revealed that those also nearly linearly decreased with BMI, which correlated to an inversely proportional local area (i.e., cross-sectional dimension) increase. Since even the most considerable difference that exists between 1st and 99th percentile BMI manikins is less than 15% of hoverall of the average manikin, it can be concluded that the impact of the human body shape on the convective heat transfer is minor.

Numerical study of location and depth of rectangular grooves on the turbulent heat transfer performance and characteristics of CuO-water nanofluid flow.

This current work expresses numerical simulation of forced turbulent flow convection in a grooved cylinder. Rectangular grooves with a spacing of A = 1, A = 1.1, and A = 1.3, and groove depth to cylinder diameter of e/D = 0.1 and 0.2 were considered. This research concentrates on the effect of groove depth, location of the grooves and CuO nanoparticles on the heat transfer for Reynolds numbers 10000, 12,500, 15,000 and 17,500 in volume fractions of 0, 1, 2, 3 and 4% of nanoparticles. Results show that grooves improve heat transfer. This behavior at a lower A ratio results in a significant Nu number increase so that the highest Nu number occurs for A ratio of 1, 1.1 and 1.3. Increasing e/D ratio, due to increasing the channel section in this area, results in loss of velocity and dissipation of flow momentum, resulting in lower convective heat transfer and lower Nu number. Changing the pitch for e/D = 0.1 results in a 1.1 to 1.6 times increase of Nu number compared with the smooth channel, and for e/D = 0.2 this value is 1.1-1.5 times the smooth channel for similar Re, φ and geometry. Changing groove pitch at e/D = 0.1 results in a 2.1-2.9 times increase in friction factor compared with the smooth channel in similar conditions. For e/D = 0.2, this increase is 1.8-2.8 times the smooth channel. In low Re, the thermal performance is higher than in higher velocities. This is because the grooved channel acts as a smooth channel at high Re, and the average Nu does not have significant growth.

Numerical and analytical solutions of new Blasius equation for turbulent flow.

The Blasius equation for laminar flow comes from the Prandtl boundary layer equations. In this article, we establish a new and generic Blasius equation for turbulent flow derived from the turbulent boundary layer equation that can be used for turbulent as well as laminar flow. The analytical and numerical solutions have been investigated under specific conditions to the developed new Blasius equation. The analytical and numerical results have been compared through tables and graphs to validate the established model. In fluid dynamics, analytical solutions to complicated systems are tedious and time-consuming. Changing one or more constraints can introduce new challenges. In this case, symbolic computation software provides an easier and more flexible solution for fluid dynamical systems, even if boundary conditions are adjusted to explain reality. Therefore, the MATLAB code is used to investigate the new third-order Blasius equation. The comparison and graphical representations demonstrate that the achieved results are encouraging.

A Review on Methods for Measurement of Free Water Surface.

Turbulent free-surface flows are encountered in several engineering applications and are typically characterized by the entrainment of air bubbles due to intense mixing and surface deformation. The resulting complex multiphase structure of the air-water interface presents a challenge in precise and reliable measurements of the free-water-surface topography. Conventional methods by manometers, wave probes, point gauges or electromagnetic/ultrasonic devices are proven and reliable, but also time-consuming, with limited accuracy and are mostly intrusive. Accurate spatial and temporal measurements of complex three-dimensional free-surface flows in natural and man-made hydraulic structures are only viable by high-resolution non-contact methods, namely, LIDAR-based laser scanning, photogrammetric reconstruction from cameras with overlapping field of view, or laser triangulation that combines laser ranging with high-speed imaging data. In the absence of seeding particles and optical calibration targets, sufficient flow aeration is essential for the operation of both laser- and photogrammetry-based methods, with local aeration properties significantly affecting the measurement uncertainty of laser-based methods.

New modified algorithm: θ-turbulent flow of water-based optimization.

The reactive power control of a power system is discussed under two types of variables: continuous variables (e.g., generator bus voltages) and discrete variables (e.g., transformer taps and the size of switched shunt capacitors). This paper proposes a novel and powerful algorithm, named turbulent flow of water-based optimization (TFWO) as well as a new improved version of this algorithm, called θ-TFWO, for optimal reactive power distribution (ORPD) to reduce losses. The proposed method is applied to two large-scale IEEE 57-bus systems. Furthermore, to demonstrate the competitive performance of the suggested algorithm, its performance was compared to that of several other algorithms, including biogeography-based optimization (BBO), social spider algorithm (SSA), and optics inspired optimization (OIO), in terms of solving the ORPD problem. The results confirmed the robustness and effectiveness of the proposed method as a powerful optimizer applicable to optimal reactive power distribution in power systems.

Transport and deposition of solid phosphorus-based mineral particles in urine diversion systems.

The deposition of solid phosphorus-based mineral particles is a common problem in urine diversion systems, which occurs in transport systems, particularly in horizontal pipelines. In this work, particle deposition behaviour in turbulent flow in a 3D horizontal pipe was simulated by using the Euler-Lagrange method. The effects of particle diameter, particle density, particle shape factor and fluid flow velocity on particle deposition behaviour were investigated. The results showed that the deposition rate increased by 9.92%,6.88% and 6.88% with increasing particle diameter (10-90 µm), particle density (1400 kg/m3-2300 kg/m3), and particle shape factor (0.2-1), respectively. For particles with larger diameters (>90 µm) or larger density (>2300 kg/m3), the deposition rate of these particles was almost reached 100%. It was found that gravitational sedimentation was the dominant deposition mechanism in low fluid flow velocity range (0.1-0.5 m/s). As fluid flow velocity increased (>0.5 m/s), turbulent fluctuation became the dominant factor that affected particle motion behaviour, whereas the effect of gravitational sedimentation on particle deposition behaviour declined significantly, and the increase in fluid flow velocity no longer significantly affects deposition rate. It was found that the deposition rate decreased by 29.13% as the fluid flow velocity was increased from 0.1 m/s to 0.5 m/s, while the corresponding deposition rate only decreased by 14.24% when the fluid flow velocity was increased from 0.5 m/s to 2 m/s. The optimal flow velocity was found to range between 0.75 and 1.25 m/s, which may mitigate the deposition of mineral solids in urine diversion systems.