Forced Flow Research Articles

Internal Mechanism and Empirical Test of Rural Industry Revitalization Driven by Digital Economy in Yangtze River Delta

Realizing the integrated development of urban and rural areas in the Yangtze River Delta is the inherent requirement of Chinese modernization and the inevitable result of the high development of productive forces. Developing digital economy has become an important means to promote the orderly and free flow of urban and rural elements and rationally allocate resources. In order to explore the influence of digital economy on urban-rural integration in the Yangtze River Delta region, this paper analyzes the direct role of digital economy on urban-rural integration and the intermediary role of factor flow on urban-rural integration in the Yangtze River Delta region by using the intermediary effect model. The research results show that the integration development level of digital economy in the Yangtze River Delta region has obviously improved, and the result effect is remarkable after the robustness test of the model. Digital economy is conducive to promoting the integration of urban and rural development; Digital economy promotes the integration of urban and rural development through the flow of rural labor force. Based on this, it is proposed to improve the sustainable mechanism of urban-rural integration development in the Yangtze River Delta region and promote the basic construction of digital economic facilities.

Analyzing the Effect of Magnetic Drag Force on Carbon Nanotubes Suspended in Casson Fluid Within Parallel Surfaces with Heat Diffusion and Rate of Molar Reaction: An Analytical Approach

The study of hydromagnetic CNTs of Casson fluids in Poiseuille flow has significant implications for various industries and can provide valuable insights into the fundamental properties, such as viscosity and conductivity of these fluids. They can improve the heat transfer properties of fluids and enhance the overall efficiency of thermal systems and the presence of CNTs can induce a magnetic field in the fluid. The main goal of using carbon nanotubes (CNTs) in Poiseuille flow is to enhance the fluid flow properties, such as viscosity, thermal conductivity, and heat transfer and the novelty of CNTs in Poiseuille flow lies in their ability to modify the fluid flow properties by altering the structure of the fluid at the nanoscale level. The use of CNTs in Poiseuille flow has gained attention due to their unique mechanical, electrical, and thermal properties. An analytical approach to the investigation of heat transmission in hydro-magnetic forces of natural convective flow of Casson-fluid in a Poiseuille flow implanted by Darcian regime on Carbon Nanotubes with the impacts of magnetic field, heat generation, diffusion thermo, porosity, radiation and first order chemical reaction is presented. In this research, dual solutions are introduced for single-wall and multiple-wall carbon nanotubes over velocity and temperature of nanofluid by the application of various physical and they are elaborated via plane curves. The base fluid is considered for the CNTs as Engine oil. Validity of this model has established by comparing with the available previous literature and is found acceptable agreement with it. In the present study, it is found that the fluctuation in radiation and heat generation plays a significant role in CNTs. It is known that a rise in the Casson parameter and nanoparticle volume fraction enhances the fluid velocity. It is concluded that, the volume fraction of nanoparticles in Poiseuille flow can have a significant impact on the flow behaviour and properties of the fluid. This study has tremendous feasible applications in the areas related to biomedical sciences, water purification process, technology of fibers, nano-materials technology, storage of energy and various applications.

Levenberg–Marquardt backpropagation neural networking (LMB-NN) analysis of hydrodynamic forces in fluid flow over multiple cylinders

The mathematical formulation of the flowing liquid stream around and through confined multiply connected domains brings a complex differential system. Due to this, one cannot provide a complete description of flow field properties. The current pagination provides a numerical remedy by the use of artificial intelligence in this direction. To be more precise, fluid is considered in the rectangular channel. The circular, square, and triangular-shaped cylinders are positioned as an obstacle to the continuous fluid. The channel’s left wall is viewed as an inlet and two different velocity profiles are introduced at an inlet that are constant and parabolic profile. To discretize the computational domain, hybrid meshing is used. The variance in basic variables, namely, the velocity of the liquid and the distribution of the liquid pressure, is recorded via graphs. The nine different meshed grades are tested for the drag and lift coefficients around the right-angle triangle, square, and circular barrier. The neural networking model is constructed by using 99 datasets of sample values for drag coefficient when characteristic length, the density of fluid, the dynamic viscosity of the fluid, and mean flow velocity are taken as inputs. The training of the neural network takes up 69 slots (about 70%), while the testing and validation of the neural network each take up 15 slots (15%). The Levenberg–Marquardt backpropagation algorithm is used for training. We have observed that for the parabolic profile, the drag coefficient is higher in intensity for each obstacle compared to the constant profile, while the lift coefficient shows opposite patterns.

Ceiling effect of flapping wing rotorcrafts to enable energy-efficient perching

Flapping wing rotorcrafts (FWRs) combine both the motion characteristics of flapping and rotary wings, exhibiting high aerodynamic efficiency at low Reynolds numbers. In this paper, the ceiling effect of FWRs has been studied through numerical and experimental methods to further investigate the aerodynamic performance of FWRs operating under a ceiling and to explore the feasibility of enhancing the flight efficiency of FWRs via ceiling-effect-based perching locomotion. Based on the momentum theory and blade element methods, a theoretical model is first established to predict the additional thrust generated by the FWR operating under the ceiling. Additionally, to uncover the detailed aerodynamic mechanisms of FWRs' ceiling effect, the computational fluid dynamics (CFD) simulations were conducted to analyze the changes in force production and flow field around the FWR at 75–115 mm distances from the ceiling. Furthermore, experimental methods were employed to validate the theoretical model and CFD simulation. The results demonstrate a continuous increase in the thrust from 19.18 to 22.15 gf as the ceiling distance decreases, while the total energy consumption remains relatively constant. Leveraging the ceiling effect, the tested FWR could achieve an additional lift force of up to 9.5% at 75 mm ceiling height with a 33 Hz flapping frequency. Finally, a ceiling perching demonstration was conducted to validate the feasibility of achieving FWRs' energy-efficient locomotion based on ceiling effects. Our study highlights the positive influence of ceiling effect on FWRs, showing a promising way to further improve the flight efficiency of FWRs.

On biomimetic surface texturing and its impact on turbulent flow and hydrodynamic forces acting on an early-stage bio-fouling organism

Recent marine anti-fouling research efforts have sought inspiration from bio-mimetic strategies to develop nontoxic solutions. Surface modifications have shown promising results in their ability to disrupt attachment and growth of early-stage organisms under static immersion conditions but very limited research has attempted to explore the interaction between surface textures and flow under turbulent conditions. The study presented in this article focuses on a simple texture, inspired by the growth rings of the Brill fish Scophthalmus rhombus and developed for applications on the blades of tidal stream turbine. A series of Large Eddy Simulations of fully developed turbulent channel flow were performed to assess the influence of the spacing between the texture elements on turbulent stresses. The aim is to characterize the impact of the texture on turbulent stresses by comparison to a smooth surface and identify whether shelters may form within the gaps between textures. The study clarifies the role of dispersive and Reynolds stresses in terms of their impact on hydrodynamic forces acting on a simplified model of a marine diatom. Reynolds shear stresses predominantly govern the intensity of forces, while dispersive shear stress affects the mean hydrodynamic forces acting on the organism at the early stage of settlement.

Experimental investigation of forced convective heat transfer and fluid flow in a mini heat pipe with rectangular micro grooves

In the present study, the convective heat transfer coefficient of water in a laminar flow regime under constant inlet temperature conditions inside a flat mini heat pipe was investigated ex-perimentally. Heat flux ranged from 20-50W and various horizontal heat sink temperatures (operating temperature) ranged from 15-35°C with liquid flow rate (3.563E-8 m3/sec) used during the experiments. The rectangular microchannels performance is evaluated in terms of the temperature profile, heat transfer coefficient, Nusselt number and thermal resistance. The results emphasized that the mini heat pipe temperature gradients are less than the tempera-ture of the copper plate and the heat resistance gradually decreases to its lowest value when the heat flux value reaches its highest value if it does not exceed the capillary limits. The data also demonstrated that the coefficient of heat transfer in the condensation zone is lower than in the evaporation zone at different heat sink temperatures. The augmentation rate for the flat mini heat pipe thermal conductivity reached about 240% at a heat load 30W for the positions of thermosyphon and horizontal, while the rate of increase in the case of the anti-gravity situ-ation at a heat load 30W reaches 210%, then the improvement percentage begins to decrease to 200%. A generalized regression equation is developed for the estimation of the Nusselt number valid for water in a flat mini heat pipe.

Numerical investigation of forced convection flow of a complex Bingham–Papanastasiou fluid between two concentric

This research presents a numerical investigation of the flow field and heat transfer of a Visco-plastic fluid, The Bingham-Papanastasiou model is used to examine the flow field and forced convection heat transfer of a Viscoplastic fluid between two concentric cylinders with a wavy inner surface. By focusing on this particular configuration (wavy inner cylinder shape), where the inner surface exhibits as the hot wall while the outer surface is considered as the cold wall. This investigation is numerically achieved by using the Comsol Multiphysics, which is based on the finite‐volume method, employing Galerkin’s method for solving the governing equations. The parameters studied in this research are expressed with the following values: r/ R=1/3, Reynolds number (Re=1, 10, 50), and undulation number (nu=0, 6, 12, 24). Increasing the inertia parameter results in a higher intensity of thermal buoyancy, positively influencing heat transfer, particularly at Re=50. Furthermore, the acceleration of flow within the investi-gated space improves the hydrodynamic behavior, facilitating the exchange of thermal energy between the hot and cold walls. Additionally, it has been discovered that an undulating shape with a specific number of undulations (nu=6) maximizes hydrothermal performance within the investigated volume. The presence of these undulations enhances fluid mixing and dis-rupts the formation of stagnant regions ,which leading to improved heat transfer.

Comparison of Forced Expiratory Flow (FEF) 25-75% between Post-COVID-19 Patients with Different Severity at Universitas Gadjah Mada Academic Hospital

Introduction: Shortness of breath is the most distressing long COVID-19 symptom associated with the decline of small airway function, as shown by a decrease in forced expiratory flow (FEF) 25-75% value in the spirometry test. This study aimed to compare FEF 25-75% values as a predictor of small airway disease between mild-moderate and severe-critical long COVID-19 patients. Methods: This study used a prospective cohort design that included 24 post-hospitalized COVID-19 patients who came to the long COVID-19 clinic at Universitas Gadjah Mada Academic Hospital (UGM AH), Yogyakarta. The subjects were divided into mild-moderate and severe-critical groups based on the World Health Organization (WHO) classification. The subjects were tested for spirometry three months after the onset of COVID-19 symptoms. The comparison of both severity groups used the percent prediction of FEF 25-75% spirometry results. The value was interpreted as abnormal if the predicted FEF 25-75% value was below 65%. Results: There were three (25%) and two (16.67%) subjects with FEF 25-75% predicted below normal values in the mild-moderate and severe-critical groups consecutively, which showed a decline in small airway function. This study showed no statistically significant differences (p-value = 0.882) between the means of FEF 25-75% predicted values of the two groups. Conclusion: A small proportion of post-COVID-19 syndrome patients had small airway disease, and there were no statistical differences in small airway function between the groups.

Fingering stabilization and adhesion force in the lifting flow with a fluid annulus.

The lifting Hele-Shaw cell flow commonly involves the stretching of a viscous oil droplet surrounded by air, in the confined space between two parallel plates. As the upper plate is lifted, viscous fingering instabilities emerge at the air-oil interface. Such an interfacial instability phenomenon is widely observed in numerous technological and industrial applications, being quite difficult to control. Motivated by the recent interest in controlling and stabilizing the Saffman-Taylor instability in lifting Hele-Shaw flows, we propose an alternative way to restrain the development of interfacial disturbances in this gap-variable system. Our method modifies the traditional plate-lifting flow arrangement by introducing a finite fluid annulus layer encircling the central oil droplet, and separating it from the air. A second-order, perturbative mode-coupling approach is employed to analyze morphological and stability behaviors in this three-fluid, two-interface, doubly connected system. Our findings indicate that the intermediate fluid ring can significantly stabilize the interface of the central oil droplet. We show that the effectiveness of this stabilization protocol relies on the appropriate choice of the ring's viscosity and thickness. Furthermore, we calculate the adhesion force required to detach the plates, and find that it does not change significantly with the addition of the fluid envelope as long as it is sufficiently thin. Finally, we detect no distinction in the adhesion force computed for stable or unstable annular interfaces, indicating that the presence of fingering at the ring's boundaries has a negligible effect on the adhesion force.

A numerical investigation on forced convection heat and mass transfer performance in a right triangular cavity

The objective of this numerical study is to examine how different Reynolds numbers impact heat and mass transfer in an unsteady forced convective two-dimensional flow within a right-angle triangular cavity. The lowest surface of the enclosure is held at a fixed temperature and concentration, whereas the slanted surface is taken to be a cool surface. Furthermore, the cavity's left wall is adiabatically positioned to move in two directions: upwards (aiding flow) and downwards (opposing flow), with a constant speed being maintained. The partial differential equations that govern the system are converted into a non-dimensional form through a straightforward transformation. The finite-element scheme is employed to solve these dimensionless equations. The analysis facilitates the investigation of the belongings of the Reynolds number on the heat and mass transfer appearances by using streamlines, isotherms, and isoconcentration lines. It is initiated that the temperature spreading as well as concentration within the cavity depends strongly on the Reynolds number. Moreover, the motion of the moving wall influences the patterns of fluid flow, temperature, and concentration fields. This study provides a comprehensive investigation into heat and mass transfer behavior occurring within a lid-driven right-angled triangular cavity moving in two opposite directions for aiding flow and opposing flow respectively.

Numerical Study of a Heat Exchanger with a Rotating Tube Using Nanofluids under Transitional Flow

Improvements in heat exchanger thermal efficiency are crucial for achieving energy use and cost reductions. The use of nanofluids and the rotation of the exchanger inner tube may enhance heat transfer and exchanger efficiency. In this work, after having performed experiments on such a heat exchanger, a three dimensional numerical model was developed to simulate the transitional forced convection flow of a horizontal double-tube heat exchanger, with the aim of obtaining insight into the effects of the inner tube rotation, fluid flow rate and type of nanofluid employed. It was found that an increase in the nanoparticle concentration up to 3% increased the exchanger efficiency. Al2O3, Al2O3-Cu and Cu-water nanofluids were studied, with the Cu-water being the fluid with the best performance (19.33% improvement). Heat transfer was enhanced with inner tube rotation up to 500 rpm (41.2%). Nevertheless, pressure drop and friction values were increased due to both phenomena, leading to higher pumping power values for the operation of the heat exchanger. Hence, a balance between the performance and pumping power increase must be considered when modifications are made on a heat exchanger. The development of the numerical model might help in further optimizing, redesigning and scaling up heat exchangers.

Impact of fractional magnetohydrodynamic and hall current on ree-eyring fluid flow by using radial basis function method

In the present work, an analysis has been arranged to study the Magnetohydrodynamic of Ree-Eyring fluid with the effect of Hall current between two parallel plates. Initially, both plates are at rest then suddenly plates are bought to steady velocities v0 and v1 at y=0 and y=d respectively. The governing problem is converted to the fractional partial differential equation and then numerically solved by using the radial basis functions collocation scheme. The Crank-Nicolson scheme is applied for the discretization of space derivatives. The numerical computation is performed for 0≤α≤1,0≤m≤1,0≤β≤1. The performance of the method is investigated with the help of tabulated results. The obtained results show the efficiency of the method for different parameters. The numerical results are compared for different fractional orders, and it is concluded that decreasing the fractional order increases the velocity which enhances the flow. Results are tabulated for different time levels, and it is concluded that method produces smooth solution for increasing values of T. Time fractional derivatives play a significant role in understanding non-Newtonian fluids and complex flow behaviors. They accurately model resistance forces in fluid flow, particularly in systems with non-standard behavior. This allows for a more detailed analysis of transient phenomena, providing valuable insights into fluid behavior over time. Ultimately, the use of time fractional derivatives enhances our capacity to describe and predict fluid flow in various practical applications such as physiology, biomedicine, and engineering.

Opposing Mixed Convection Heat Transfer for Turbulent Single-Phase Flows

Convection, wherein forced and natural convections are prominent, is known as mixed convection. Specifically, when a forced convection flow is downward, this flow is called opposing flow. The objectives of this study are to gain a comprehensive understanding of opposing flow mixed convection heat transfer and to establish the prediction methodology by evaluating existing correlations and models. Several heat transfer correlations have been reported related to single-phase opposing flow; however, these correlations are based on experiments conducted in various channel geometries, working fluids, and thermal flow parameter ranges. Because the definition of nondimensional parameters and their validated range confirmed by experiments differ for each correlation reported in previous studies, establishing a guideline for deciding which correlation should be selected based on its range of applicability and extrapolation performance is important. This study reviewed the existing heat transfer correlations for turbulent opposing flow mixed convection and the single-phase heat transfer correlations implemented in the thermal–hydraulic system codes. Furthermore, the authors evaluated the predictive performance of each correlation by comparing them with the experimental data obtained under various experimental conditions. The Jackson and Fewster, Churchill, and Swanson and Catton correlations can accurately predict all the experimental data. The effect of the difference in the thermal boundary conditions, i.e., uniform heat flux and uniform wall temperature, on the turbulent mixed convection heat transfer coefficient is not substantial. The authors confirmed that heat transfer correlations using the hydraulic-equivalent diameter as a characteristic length can be used for predictions regardless of channel-geometry differences. Furthermore, correlations described based on nondimensional dominant parameters can be used for predictions regardless of the differences in working fluids. The authors investigated the extrapolation performance of the mixed convection heat transfer correlations for a wide range of nondimensional parameters and observed that the Jackson and Fewster, Churchill, and Aicher and Martin correlations exhibit excellent extrapolation performance with respect to natural and forced convection flows, indicating that they can be applied beyond the parameter range validated experimentally.

The Fate of Microplastics, Derived from Disposable Masks, in Natural Aquatic Environments.

This paper mainly reviews the fate of microplastics, released from used face masks, in the water environment. Through previous experiments, the amount of fiber microplastics released from used face masks into aqueous environments was not negligible, with the maximum microplastics releasing amount reaching 10,000 piece·day-1 for each mask. Microplastic derived from these masks often occurred in the shape of polymeric fibers that resulted from the breakage of the chemical bonds in the plastic fibers by the force of water flow. The potential contact forces between microplastics (originating from face masks) with other pollutants, primarily encompass hydrophobic and electrostatic interactions. This critical review paper briefly illustrates the fate of microplastics derived from disposable face masks, further devising effective strategies to mitigate the environmental impact of plastic particle release from the used personal protective equipment.

Investigation of forced convection of a novel hybrid nanofluid containing NEPCM in a square microchannel: Application of single-phase and Eulerian-Eulerian two-phase models

In the present study, laminar forced convection flow and heat transfer of novel hybrid nanofluid of Al 2 O 3 -n-octadecane/water through a horizontal microchannel under a constant wall heat flux condition are investigated. N-octadecane is regarded as a nano-encapsulated phase change material (NEPCM). Simulations are performed utilizing single-phase and Eulerian-Eulerian two-phase models. Governing equations are discretized by finite volume method and then solved using SIMPLE algorithm. Effects of nanoparticles volume fraction ( φ ), Reynolds number ( Re ), and melting range ( T mr ) on thermal and hydrodynamic parameters of hybrid nanofluid are evaluated. It is shown that predictions by Eulerian-Eulerian approach are more accurate than those by single-phase approach when compared to available experimental data. Addition of Al 2 O 3 and n-octadecane nanoparticles to water-based fluid leads to a reduction in fluid and wall temperatures, which is intensified at higher φ and Re . Also, these nanoparticles do not have a significant effect on hydrodynamic development of flow, while they delay its thermal development. NEPCM with a higher T mr only slightly improves thermal performance of hybrid nanofluid, which is more noticeable in single-phase procedure. Total efficiency of hybrid nanofluid ( η hnf ) is amplified by raising φ for both approaches. This augmentation is more evident in Eulerian-Eulerian model due to better thermal and hydrodynamic performances. Maximum increases in η hnf concerning single-phase and Eulerian-Eulerian models are 27% and 60%, respectively, occurring at φ Al 2 O 3 = 1 % and φ n ‐ octadecane = 10 % . Therefore, this type of hybrid nanofluids, because of its enhanced thermo-physical properties, can be considered as a suitable candidate for thermal energy storage, heat transfer, and renewable energy applications.

Force balance ratio is a robust predictor of arterial thrombus stability

Thrombus formation on a damaged vessel wall can lead to the formation of a stable occlusive/subocclusive clot or unstable embolizing thrombus. Both outcomes can cause significant health damage. The mechanisms that regulate maximum thrombus size, its stability, and embolization in both micro- and macrocirculation are poorly understood. To investigate the impact of flow and intrathrombus forces on the stability of homogeneous and heterogeneous platelet thrombi in a wide range of thrombus geometries, critical interplatelet forces, vessel diameters, and hydrodynamic conditions, we took advantage of the recently developed in silico models. To perform analysis of thrombus stability/embolization in arterioles, we used our previously developed particle-based 2D model with a single-platelet resolution. Its results and predictions were further extended to a 3D case and the large spatial scales of arteries using novel particle-based and continuum 3D models. We found a robust quantitative parameter, termed force balance ratio, which quantifies the balance between destabilizing hydrodynamic and stabilizing interplatelet forces. This parameter predicts whether a homogeneous thrombus (or the shell of a heterogeneous thrombus) with a particular value of critical interplatelet forces will embolize under given hydrodynamic conditions. Our simulations also predict that, for a given magnitude of critical interplatelet forces, the longer thrombi are more stable than the shorter ones. Furthermore, the aggregates formed on top of the severe stenosis are more stable than thrombi formed at moderate stenosis. Taken together, our results give new insights into the interplay between critical interplatelet forces, local hydrodynamics, and overall thrombus stability against the flow.

Harmonic Turbulent Stress Budgets in Forced Transonic Flow over a Bump

The transonic flow over a bump is studied using implicit large-eddy simulations. To replicate rotor/stator interactions occurring in turbomachinery, harmonic forcing of the backpressure is imposed at the outlet. Various perturbation frequencies are prescribed and encompass different regimes, from a fully locked configuration to a decoupling between the unperturbed and forced flows. The mean solution is, however, found to be independent of the perturbation. In a triple-decomposition framework, the coherent component of the flow is extracted by phase averaging. Organized structures of streamwise velocity and turbulence kinetic energy are highlighted. Whereas these structures are of similar shapes beneath the shock system, their extent in the downstream boundary layer is controlled by the frequency of the perturbation. The mean and harmonic turbulent stress budgets are presented. A typical three-peak distribution of mean turbulent diffusion is reported, which is also found to appear for coherent turbulent diffusion. Harmonic production arises mainly from the mean shear and its modulation.

Gene Flow and Isolation in the Arid Nearctic Revealed by Genomic Analyses of Desert Spiny Lizards.

The opposing forces of gene flow and isolation are two major processes shaping genetic diversity. Understanding how these vary across space and time is necessary to identify the environmental features that promote diversification. The detection of considerable geographic structure in taxa from the arid Nearctic has prompted research into the drivers of isolation in the region. Several geographic features have been proposed as barriers to gene flow, including the Colorado River, Western Continental Divide (WCD), and a hypothetical Mid-Peninsular Seaway in Baja California. However, recent studies suggest that the role of barriers in genetic differentiation may have been overestimated when compared to other mechanisms of divergence. In this study, we infer historical and spatial patterns of connectivity and isolation in Desert Spiny Lizards (Sceloporus magister) and Baja Spiny Lizards (Sceloporus zosteromus), which together form a species complex composed of parapatric lineages with wide distributions in arid western North America. Our analyses incorporate mitochondrial sequences, genomic-scale data, and past and present climatic data to evaluate the nature and strength of barriers to gene flow in the region. Our approach relies on estimates of migration under the multispecies coalescent to understand the history of lineage divergence in the face of gene flow. Results show that the S. magister complex is geographically structured, but we also detect instances of gene flow. The WCD is a strong barrier to gene flow, while the Colorado River is more permeable. Analyses yield conflicting results for the catalyst of differentiation of peninsular lineages in S. zosteromus. Our study shows how large-scale genomic data for thoroughly sampled species can shed new light on biogeography. Furthermore, our approach highlights the need for the combined analysis of multiple sources of evidence to adequately characterize the drivers of divergence.

GET 63–2019: Innovative Method for Stabilizing Liquid Flow Rate in a Reference Installation 3

Establishing the pinpoint accuracy of national primary standards for units of mass and volume flow rates (mass and volume) of liquid (water) is a priority in the national economy of most states. In Russia and abroad, the principle of operation of standards for units of flow rate and amount of liquid is based on the gravimetric weighing method, i. e., on measuring the mass of liquid entering a weighing container over a certain averaging time interval. The decisive condition for the accuracy of the result of the standard is the stabilization of liquid flow rate, as well as the choice of the optimal method for creating a forced flow of liquid in the pressure pipeline and measuring line. The widely accepted method of creating a forced flow of liquid by placing it at a height or supplying it using pumps has one inconvenient consequence – the bulkiness of the standard design. The creation of such a design entails economic, labor, and time costs, which can adversely affect the test conditions and results. The author’s innovative method of active damping of pressure and fluid flow fluctuations, which eliminates the need to place the pressure tank at a great height above ground level, allows minimizing inconveniences. This method is implemented in the pressure pipeline and measuring line of the reference installation 3 of the State Primary Special Standard of Units of Mass and Volume of Liquid in a Flow and of Mass and Volume Flow Rates of a Liquid GET 63–2019. The purpose of the article is to substantiate and experimentally confirm the high efficiency of this method. The results of experimental research of changes in the absolute pressure in the air cushion and the liquid level in the pressure tank of the stabilization module confirmed the efficiency of the proposed method based on the obtained minimum values of the relative deviations of the instantaneous and average liquid flow rates. The engineering solution presented in the article is of interest to economic entities and commercial organizations interested in reducing the costs of testing the volumetric flow rate (mass and volume) of liquid (water).

Investigating clot-flow interactions by integrating intravital imaging with in silico modeling for analysis of flow, transport, and hemodynamic forces

As a blood clot forms, grows, deforms, and embolizes following a vascular injury, local clot-flow interactions lead to a highly dynamic flow environment. The local flow influences transport of biochemical species relevant for clotting, and determines the forces on the clot that in turn lead to clot deformation and embolization. Despite this central role, quantitative characterization of this dynamic clot-flow interaction and flow environment in the clot neighborhood remains a major challenge. Here, we propose an approach that integrates dynamic intravital imaging with computer geometric modeling and computational flow and transport modeling to develop a unified in silico framework to quantify the dynamic clot-flow interactions. We outline the development of the methodology referred to as Intravital Integrated In Silico Modeling or IVISim, and then demonstrate the method on a sample set of simulations comprising clot formation following laser injury in two mouse cremaster arteriole injury model data: one wild-type mouse case, and one diYF knockout mouse case. Simulation predictions are verified against experimental observations of transport of caged fluorescent Albumin (cAlb) in both models. Through these simulations, we illustrate how the IVISim methodology can provide insights into hemostatic processes, the role of flow and clot-flow interactions, and enable further investigations comparing and contrasting different biological model scenarios and parameter variations.