Average Flow Speed Research Articles

Patterns of lean methane-air mixtures combustion in piston engine

The article is devoted to the study of the patterns of combustion of lean methaneair mixtures in marine internal combustion engine. Literature review shows that the implementation of combustion technology for a homogeneous lean methaneair mixture will increase the compression ratio, reduce fuel consumption and improve the environmental engine performance. However due to an increase in misfires and a decrease in the speed of flame propagation, the combustion of lean methaneair mixtures remains an unresolved problem. The article studies the influence of the excess air coefficient (from 1 to 1.4) on the turbulent combustion regime (assessed by the Karlowitz and Damkoehler criteria), the completeness and rate of fuel combustion. It was revealed that depletion of the air fuel mixture under conditions of intense turbulence leads to an increase in the Karlowitz criterion and a decrease in the Damköhler criterion. This indicates that the rate of chemical reactions in the flame front decreases, as a result of which the combustion process is characterized by stretching and rupture of the flame front. Therefore, to intensify the combustion of lean methaneair mixtures, it is advisable to increase the average speed of the vortex flow, and not the intensity of turbulence. A study of the influence of the excess air coefficient on the completeness and rate of fuel combustion showed that depletion of the mixture leads to a decrease in the completeness of fuel combustion from 93.5 % (at α=1) to 83 % (at α=1.4). The combustion rates also decrease and their maximum values shift from 13° (at α=1) to 24° (at α=1.4) degrees after top dead center. Therefore for efficient engine operation on lean mixtures, it is necessary to increase the fuel combustion rate through additional swirling of the gasair mixture or the use of combustion promoters.

High-resolution 3D hydrodynamic modeling and comprehensive assessment of tidal current energy resources

As a clean and renewable resource, tidal current holds significant development potential. However, accurately assessing tidal current energy resources has been a persistent challenge. This study proposes a comprehensive assessment method using a small-scale, high-precision, multi-criteria three-dimensional hydrodynamic model to assess resource reserves applied to the Zhairuoshan Waterway. The hydrodynamic model was employed to simulate critical parameters such as tidal level, flow velocity, and flow direction. Multiple statistical indicators were used to evaluate the model's accuracy, showing consistency. The study analysed the flow speed distribution over a complete cycle, revealing an average flow speed of 1.51 m/s, with a maximum speed reaching 3.83 m/s. The generally high flow speeds within the waterway, coupled with the stability of the tidal current, indicate the significant resource potential of the study area. A quantitative analysis of the spatial distribution of tidal current energy was conducted using energy flux density, and the results showed that high energy density areas are widely distributed. Furthermore, the theoretical tidal energy resources of the waterway were calculated, showing that the maximum resource reserves could reach 9.98 MW at the selected cross-sections. Coupled with the analysis of unit-width energy flux, the high-potential areas within the waterway were further identified.

Road Traffic Noise Levels Estimations by means of Fully Dynamic and Microscopic Approach Compared to CNOSSOS-EU Model

In the last decades, research has been dedicated to refining models for assessing traffic noise levels, supporting national authorities in addressing associated problems. Progress has shifted from basic statistical models to dynamic ones, typically composed of a Noise Emission Model (NEM) for estimating source sound power levels and a sound propagation model for assessing equivalent noise levels at specific receiver points. These models commonly integrate the average speed of traffic flow as an input variable, placing them in the macroscopic or mesoscopic realm. The CNOSSOS-EU model (reference in Europe) exemplifies this macroscopic approach. However, due to the modular structure of road traffic noise models, a NEM can be coupled with different sound propagation models, facilitating the transition from macroscopic to microscopic assessments. This paper demonstrates the coupling of a NEM with two distinct simplified sound propagation models: CNOSSOS-EU and the sum of Sound Exposure Levels (SEL) models. The latter approach showcases the potential of using individual on-road vehicle speeds as inputs, enabling microscopic noise assessments. Vehicle speed data is extracted from video records, while the goodness of the proposed approaches is tested by comparing the models' estimations with ground truth values recorded on a National Road in Portugal.

Numerical model of changes in current patterns due to reclamation around the Mireng River estuary, Gresik

Abstract The Mireng River is in Gresik Regency and empties into the Madura Strait. Around the mouth of the Mireng River, two industrial areas require construction facilities through reclamation. The consequences of reclamation will cause phenomena due to the interaction of marine and environmental dynamics, which can change current patterns, wave heights, and sedimentation processes, affecting the surrounding environment. This study explicitly discusses the changes in flow patterns that occur due to reclamation. The investigation was performed using numerical model simulations with Delft 3D software. The model results show the movement pattern and current speed during the highest and lowest low tides. There was a change in the average flow speed to 0.18 m/s around the reclamation area due to flow obstruction due to reclamation. This condition has the potential for sedimentation to occur in the area. Therefore, mitigation efforts are needed to reduce this impact.

An Improved Longitudinal Driving Car-Following System Considering the Safe Time Domain Strategy.

Car-following models are crucial in adaptive cruise control systems, making them essential for developing intelligent transportation systems. This study investigates the characteristics of high-speed traffic flow by analyzing the relationship between headway distance and dynamic desired distance. Building upon the optimal velocity model theory, this paper proposes a novel traffic car-following computing system in the time domain by incorporating an absolutely safe time headway strategy and a relatively safe time headway strategy to adapt to the dynamic changes in high-speed traffic flow. The interpretable physical law of motion is used to compute and analyze the car-following behavior of the vehicle. Three different types of car-following behaviors are modeled, and the calculation relationship is optimized to reduce the number of parameters required in the model's adjustment. Furthermore, we improved the calculation of dynamic expected distance in the Intelligent Driver Model (IDM) to better suit actual road traffic conditions. The improved model was then calibrated through simulations that replicated changes in traffic flow. The calibration results demonstrate significant advantages of our new model in improving average traffic flow speed and vehicle speed stability. Compared to the classic car-following model IDM, our proposed model increases road capacity by 8.9%. These findings highlight its potential for widespread application within future intelligent transportation systems. This study optimizes the theoretical framework of car-following models and provides robust technical support for enhancing efficiency within high-speed transportation systems.

The Causes of Platelet Aggregation in Version 6.4 Trima Accel Automated Blood Collection System and the Comparison of Two Intervention Measures

To explore the causes of platelet aggregation in version 6.4 Trima Accel automated blood collection system and the effect of 2 intervention measures. The data on platelet aggregation (n=61) and non-aggregation (n=323) of 61 donors in 2020 were collected and the causes of aggregation were analyzed. Then the 72 donors with platelet aggregation in 2021 were randomized into intervention group A (increasing the anticoagulant-to-blood ratio) and intervention group B (wrapping the donor's arm with an electric blanket to keep warm and improve the blood flow speed). The collection time, average blood flow speed, number of machine alarms, anticoagulant usage, deaggregation and citrate reaction of the two groups were compared. Platelet aggregation was negatively correlated with the average blood flow speed (r =-0.394) and positively correlated with the collection time (r =0.458). The equations for predicting aggregation and non-aggregation were constructed based on Bayesian and Fisher discriminant analysis, and the predicted accuracy was 77.1%. The comparison of the effects of two intervention measures showed that the average blood flow speed in group B was higher than that in group A; the collection time, number of machine alarms, anticoagulant usage and proportion of citrate reaction in blood donors in group B were all lower than those in Group A, all these differences were significant (P < 0.05). In the entire cohort in 2021, 90.28% of the products were immediately deaggregated after collection, and 9.72% of the products were deaggregated within 4 hours. There was no statistically significant difference in deaggregation between the two intervention groups (P >0.05). During apheresis platelet collection, the predictive equations for aggregation and non-aggregation can be used to predict the occurrence probability of aggregation, and the intervention can be made in advance. Both intervention measures are effective in reducing platelet aggregation, however, measure B has the advantages of improving the speed of blood collection, shortening the collection time, reducing the alarm frequency and the anticoagulant usage, and reducing the incidence of citrate reaction in blood donors.

Resilient spatial design strategies research of urban inland rivers: The case of Xinghai Lake wetland in Ningxia, China

Improving the resilience of rivers is a crucial method for mitigating urban flooding, restoring the ecological role of rivers, and promoting sustainable ecological development. This study specifically examines the relationship between changes in river morphology and river elasticity space, using the Xinghai Lake wetland as a case study. The MIKE 21 numerical model is employed to simulate and analyze the morphology changes of Xinghai Lake under various conditions during both the low-water and high-water periods. The findings indicated that during the period of abundant water, the inundation area of Xinghai Lake increased by 1.64 times, the average water level rose by 0.96 m, and the average flow speed decreased by approximately 11.8 % compared to the flat water period under the circulating condition within the lake. By utilizing Xinghai Lake as a channel for overflowing Yellow River water, the stability of the lake's body is improved. When Xinghai Lake is utilized as the channel for water from the Yellow River, it contributes to the increased stability of the lake. Based on the morphological characteristics of various river sections, this study identifies the potential areas for scouring, eutrophication, and flooding in the future. It also suggests specific strategic solutions to improve the resilience and ecological robustness of the river. These proposals aim to provide scientific support for enhancing the ecological robustness of urban inland lakes.

Vector-flow imaging of slowly moving ex vivo blood with photoacoustics and pulse-echo ultrasound

We present a technique called photoacoustic vector-flow (PAVF) to quantify the speed and direction of flowing optical absorbers at each pixel from acoustic-resolution PA images. By varying the receiving angle at each pixel in post-processing, we obtain multiple estimates of the phase difference between consecutive frames. These are used to solve the overdetermined photoacoustic Doppler equation with a least-squares approach to estimate a velocity vector at each pixel. This technique is tested in bench-top experiments and compared to simultaneous pulse-echo ultrasound vector-flow (USVF) on whole rat blood at speeds on the order of 1 mm/s. Unlike USVF, PAVF can detect flow without stationary clutter filtering in this experiment, although the velocity estimates are highly underestimated. When applying spatio-temporal singular value decomposition clutter filtering, the flow speed can be accurately estimated with an error of 16.8% for USVF and −8.9% for PAVF for an average flow speed of 2.5 mm/s.

Variation in the Pedersen Conductance Near Jupiter's Main Emission Aurora: Comparison of Hubble Space Telescope and Galileo Measurements

AbstractWe present the first large‐scale statistical survey of the Jovian main emission (ME) to map auroral properties from their ionospheric locations out into the equatorial plane of the magnetosphere, where they are compared directly to in‐situ spacecraft measurements. We use magnetosphere‐ionosphere (MI) coupling theory to calculate currents from the auroral brightness as measured with the Hubble Space Telescope and from plasma flow speeds measured in‐situ with the Galileo spacecraft. The effective Pedersen conductance of the ionosphere remains a free parameter in this comparison. We calculate the Pedersen conductance from the combined data sets, and find it ranges from mho overall with averages of mho in the north and mho in the south. Considering the HST‐derived field‐aligned currents per radian of azimuth only, we find values of MA rad−1 and MA rad−1 in the north and south, respectively, in general agreement with previous results. Taking the currents and effective Pedersen conductance together, we find that the average ME intensity and plasma flow speed in the middle magnetosphere (10–30 RJ) are broadly consistent with one another under MI coupling theory. We find evidence for peaks in the distribution of near dawn, then again near 12 and 14 hr magnetic local time (MLT). This variation in Pedersen conductance with MLT may indicate the importance of conductance in modulating MLT‐ and local‐time‐asymmetries in the ME, including the apparent subcorotation of some auroral features within the ME.

A SLIP-based post-failure model to predict the propagation of soil slips and their interaction with infrastructures.

Rainfall-induced shallow landslides (also called soil slips) are natural phenomena which can be triggered suddenly anywhere, even in areas with no previous landslide history, causing unexpected damage when interacting with the built environment. The damage could be sometimes extensive, as occurred to the “Madonna del Monte” overpass located in the Italian highway A6 (Torino-Savona), which collapsed in November 2019 because of the interference of a large soil slip. This paper shows a new methodology to analyze the propagation of soil slips and their interference with infrastructures, with specific attention to roads. Failure is detected through the physically-based model SLIP, while the post-failure evolution is investigated through a simplified model, based on SLIP results and the geomorphology of the area. The proposed approach is applied to an area in Enna (Sicily, southern Italy) where on 2nd February 2014 shallow landslides were triggered after intensive rainfall, interfering with the Provincial Road SP2 and the State Road SS117bis. Volume and average speed of the debris flow are estimated by the model and could be used in further analyses of impact with the surrounding infrastructures, showing the potential of the methodology.

A Study on Environmental Impact of Slow Moving Electric Vehicles Using Microsimulation on Lucknow Urban Road With an On-Ramp.

The adoption of electric vehicles for mobility is seen as a major step towards the conservation of the environment. In India, slow-moving Electric 3-Wheelers (E3Ws) have been adopted for last-mile connectivity. The present study investigated the impact of slow-moving electric 3-wheelers on the environment in terms of emissions and traffic performance in mixed conditions. Field traffic data from a section of road in the city of Lucknow was collected and used for the calibration of the traffic model. A total of 6 scenarios were tested using traffic modelling in the open-source microsimulation software SUMO. Krauss model was used to model mixed traffic and HBEFA 4 was used to calculate the emissions of fuel-driven vehicles. In each scenario, the volume of fuel-driven vehicles was kept constant and the volume of E3Ws was varied. For the last 2 scenarios, E3Ws were replaced with modified Electric 3-wheelers (ME3Ws) and Electric Buses. Initial findings showed that the average emission decreased as the number of slowly moving electric vehicles increased, but the average flow and harmonic mean speed decreased by 49.8% and 28.8%, respectively, despite keeping the original composition of fuel-driven vehicles the same in every scenario. Further analysis of scenarios revealed a strong correlation () between the reduction in the number of vehicles and the reduction in emissions like Carbon Dioxide (), which is responsible for global warming. Scenarios in which faster electric vehicles and electric buses replace slow-moving E3Ws also demonstrate emission reduction without noticeably affecting traffic performance parameters. The study shows that the environmental benefits of E3Ws in a limited section of Lucknow road are offset by their low-speed capability. Hypothetical scenarios wherein Modified E3Ws and Electric Buses were introduced reported benefits both in terms of emissions and traffic performance.

Simulate the current dynamics process and predict the trajectory of plastic waste flowing out to sea from estuaries in the Gulf of Tonkin

This paper presents the results of a numerical simulation of flow dynamics in the northern Vietnam Sea. Based on these results, the trajectories of plastic waste from river mouths in the northern Vietnam Sea are predicted. The numerical simulation is based on the ROMS model for the northern Vietnam Sea and surrounding areas, in combination with data collected from a Vietnam-France international cooperation project (Study, evaluation, and prediction of the transport and dispersion of small plastic waste in the Van Uc River mouth area). The dynamic regime of the study area is considered to simulate the main wind seasons. The results show that the flow field in the Northern Vietnam Sea follows the tidal phases. In the rising tide phase, the general trend is for the flow to move from the south to the north. Conversely, in the falling tide phase, the general trend is for the flow to move from the north to the south. The flow speed in the tidal phases is largest at about 65-70 cm/s and smallest at about 5-10 cm/s. The much larger surrounding area outside the Northern Vietnam Sea has a very complex flow field, with many different flow areas and vortices. There is a belt of vortices that extends for hundreds of kilometers, with an average flow speed that is higher than the flow in the Northern Vietnam sea. Based on the flow field and the frequency of occurrence in the area near the Vietnamese coast where rivers flow out, the frequency of flow flowers are used to predict the trajectories of plastic waste from river mouths into the sea. The results of the calculations and predictions, when compared with the actual data, show good agreement.

One million years of Mediterranean outflow strength

An orbitally tuned age model is established, based principally on sortable silt mean grainsize (SS¯, proxy for flow speed), for sediments deposited under the influence of the Mediterranean Outflow (MO) at IODP Site U1389 in the Gulf of Cadiz. The possibility of tuning sortable silt grainsize to insolation was indicated by close agreement between these two parameters on an earlier isotopically-based age model for the upper 130 m of the core. This led to tuning of the whole 390 m-long record with addition of a magnetic susceptibility control at Marine Isotope Stage 16, and the last occurrence of R. asanoi datum at around 900 ka (now dated at 910 ka in this core).The strongest variability in SS¯ is precessional with speed maxima at insolation minima superimposed on an increase in flow speed from 620 ka to the present. Although the Gibraltar sill exercises a major control on the inflow and outflow to the Mediterranean, there is little change in flow depth over most 20 ka precessional cycles, and therefore minor hydraulic control. Accelerations in average flow speed are also seen in interglacial to glacial (IG-G) cycles, particularly after 550 ka, with strong speed maxima at maximum glacial lowering of sealevel. This has allowed calculation of the sensitivity of flow speed to sea-level (SL) change of ∼0.074 cm s−1/m. From 990 to 620 ka the average amplitude of precessional speed changes is 3.7 cm s−1, but this increases to 7.7 cm s−1 from 620 ka to present.Deep ocean flow speeds are mainly density driven. Previous work has demonstrated that the major drivers of this system's density on precessional timescales are the evaporation - precipitation - inflow balance in the eastern Mediterranean plus cooling in the Gulf of Lions. Published benthic δ18O for 125–235 ka (corrected for ice volume changes) which tracks the combination of seawater temperature and salinity that controls density, demonstrates that flow speed and density maxima are coincident for that period and probably for the whole record. Although precessional SL changes are too small to affect flow speed significantly, SL does control accelerations at glacial maxima because shallower flow depth reduces inflow and leads to longer evaporation time, resulting in increased outflow density and speed. The sensitivity of flow speed to sill depth changes has allowed estimation of the long-term shallowing of the Gibraltar sill of ∼68 m over the last 620 ka in agreement with dated terrace uplift.

Turbulence dynamics and flow speeds in the inner solar corona: results from radio-sounding experiments by the Akatsuki spacecraft

ABSTRACT The solar inner corona is a region that plays a critical role in energizing the solar wind and propelling it to supersonic and supra-Alfvénic velocities. Despite its importance, this region remains poorly understood because of being least explored due to observational limitations. The coronal radio-sounding technique in this context becomes useful as it helps in providing information in parts of this least explored region. To shed light on the dynamics of the solar wind in the inner corona, we conducted a study using data obtained from coronal radio-sounding experiments carried out by the Akatsuki spacecraft during the 2021 Venus-solar conjunction event. By analysing X-band radio signals recorded at two ground stations (Indian Deep Space Network in Bangalore and Usuda Deep Space Center in Japan), we investigated plasma turbulence characteristics and estimated flow speed measurements based on isotropic quasi-static turbulence models. Our analysis revealed that the speed of the solar wind in the inner corona (at heliocentric distances from 5 to 13 solar radii), ranging from 220 to 550 km s−1, was higher than the expected average flow speeds in this region. By integrating our radio-sounding results with extreme ultraviolet (EUV) images of the solar disc, we gained a unique perspective on the properties and energization of high-velocity plasma streams originating from coronal holes. We tracked the evolution of fast solar wind streams emanating from an extended coronal hole as they propagated to increasing heliocentric distances. Our study provides unique insights into the least-explored inner coronal region by corroborating radio-sounding results with EUV observations of the corona.

Human brain solute transport quantified by glymphatic MRI-informed biophysics during sleep and sleep deprivation.

Whether you are reading, running or sleeping, your brain and its fluid environment continuously interacts to distribute nutrients and clear metabolic waste. Yet, the precise mechanisms for solute transport within the human brain have remained hard to quantify using imaging techniques alone. From multi-modal human brain MRI data sets in sleeping and sleep-deprived subjects, we identify and quantify CSF tracer transport parameters using forward and inverse subject-specific computational modelling. Our findings support the notion that extracellular diffusion alone is not sufficient as a brain-wide tracer transport mechanism. Instead, we show that human MRI observations align well with transport by either by an effective diffusion coefficent 3.5[Formula: see text] that of extracellular diffusion in combination with local clearance rates corresponding to a tracer half-life of up to 5h, or by extracellular diffusion augmented by advection with brain-wide average flow speeds on the order of 1-9 [Formula: see text]m/min. Reduced advection fully explains reduced tracer clearance after sleep-deprivation, supporting the role of sleep and sleep deprivation on human brain clearance.

Effects of spray pattern and piston shape on in-cylinder flow in a two-cylinder spray-guided gasoline direct-injection optical engine

In gasoline direct-injection engines, in-cylinder flow plays an important role in terms of fuel atomization, mixture, turbulence, combustion, and emission. The in-cylinder flow is affected by the air–fuel interaction and piston shapes, and it is required to understand and optimize these influences. In this study, visualization of in-cylinder flow was performed depending on the piston shape and spray pattern using particle image velocimetry measurements in a two-cylinder optical engine with high-compression ratio and spray-guided direct-injection. Effects of these parameters were evaluated quantitatively by calculating average flow speed, average tumble ratio, and average turbulent kinetic energy. The mixture was confirmed using numerical simulation. The piston shape had no significant effect on the structure and strength of the in-cylinder flow. The 7-hole injector with asymmetrical spray patter was more effective to enhance the turbulence than the 10-hole injector with symmetrical spray pattern. As the injection timing was delayed up to before top dead center 120°, the average turbulent kinetic energy after fuel injection increased by up to 574 % in the 7-hole injector. However, considering stratification and possible knock region, ideal mixtures were found in the injection timing range of before top dead center 270° to 210° in both injectors.

Flow patterns and defect dynamics of active nematic liquid crystals under an electric field.

The effects of an electric field on the flow patterns and defect dynamics of two-dimensional active nematic liquid crystals are numerically investigated. We found that field-induced director reorientation causes anisotropic active turbulence characterized by enhanced flow perpendicular to the electric field. The average flow speed and its anisotropy are maximized at an intermediate field strength. Topological defects in the anisotropic active turbulence are localized and show characteristic dynamics with simultaneous creation of two pairs of defects. A laning state characterized by stripe domains with alternating flow directions is found at a larger field strength near the transition to the uniformly aligned state. We obtained periodic oscillations between the laning state and active turbulence, which resembles an experimental observation of active nematics subject to anisotropic friction.

Physical and chemical characteristics of active sulfur flows observed at Lastarria volcano (northern Chile) in January 2019

Molten sulfur is found in various subaerial volcanoes. However, limited records of the pools and flows of molten sulfur have been reported: therefore, questions remain regarding the physicochemical processes behind this phenomenon. A suite of new sulfur flows, some of which active, was identified at the Lastarria volcano (northern Chile) and studied using satellite imagery, in situ probing, and temperature and video recording. This finding provides a unique opportunity to better understand the emplacement mechanisms and mineral and chemical compositions of molten sulfur, in addition to gaining insight into its origin. Molten sulfur presented temperatures of 124–158°C, with the most prolonged sulfur flow reaching 12 m from the source. Photogrammetric tools permitted the identification of levees and channel structures, with an estimated average flow speed of 0.069 m/s. Field measurements yielded a total volume of 1.45 ± 0.29 m3 of sulfur (equivalent to ∼2.07 tons) mobilized during the January 2019 event for at least 408 min. Solidified sulfur was composed of native sulfur with minor galena and arsenic- and iodine-bearing minerals. Trace element analysis indicated substantial enrichment of Bi, Sb, Sn, Cd, as well as a very high concentration of As (&amp;gt;40.000 ppm). The January 2019 molten sulfur manifestations in Lastarria appear to be more enriched in As compared to the worldwide known volcanoes with molten sulfur records, such as the Shiretoko-Iozan and Poás volcanoes. Furthermore, their rheological properties suggest that the “time of activity” in events such as this could be underestimated as flows in Lastarria have moved significantly slower than previously thought. The origin of molten sulfur is ascribed to the favorable S-rich chemistry of fumarolic gases and changes in host rock permeability (fracture opening). Molten sulfur in Lastarria correlates with a peak in activity characterized by high emissions of SO2 and other acid species, such as HF and HCl, in addition to ground deformation. Consequently, molten sulfur was framed within a period of volcanic unrest in Lastarria, triggered by changes in the magmatic-hydrothermal system. The appearance of molten sulfur is related to physicochemical perturbations inside the volcanic system and is perhaps a precursor of eruptive activity, as observed in the Poás and Turrialba volcanoes.

Magnetohydrodynamics in free surface liquid metal flow relevant to plasma-facing components

While flowing Liquid Metal (LM) Plasma-Facing Components (PFCs) represent a potentially transformative technology to enable long-pulse operation with high-power exhaust for fusion reactors, Magnetohydrodynamic (MHD) drag in the conducting LM will reduce the flow speed. Experiments have been completed in the linear open-channel LMX-U device [Hvasta et al 2018 Nucl. Fusion 58 01602] for validation of MHD drag calculations with either insulating or conducting walls, with codes similar to those used to design flowing LM PFCs for a Fusion Nuclear Science Facility [Kessel et al 2019 Fusion Sci. Technol. 75 886]. We observe that the average channel flow speed decreased with the use of conducting walls and the strength of the applied transverse magnetic field. The MHD drag from the retarding Lorentz force resulted in an increase of the LM depth in the channel that ‘piled up’ near the inlet, but not the outlet. As reproduced by OpenFOAM and ANSYS CFX calculations, the magnitude and characteristics of the pileup in the flow direction increased with the applied traverse magnetic field by up to 120%, as compared to the case without an applied magnetic field, corresponding to an average velocity reduction of ∼45%. Particle tracking measurements confirmed a predicted shear in the flow speed, with the surface velocity increasing by 300%, despite the 45% drop in the average bulk speed. The MHD effect makes the bulk flow laminarized but keeps surface waves aligned along the magnetic field lines due to the anisotropy of MHD drag. The 3D fringe field and high surface velocity generate ripples around the outlet region. It was also confirmed that the MHD drag strongly depends on the conductivity of the channel walls, magnetic field, and volumetric flow rate, in agreement with the simulations and a developed analytical model. These validated models are now available to begin to determine the conditions under which the ideal LM channel design of a constant flow speed and fluid depth could be attained.

Human blood circulation model based on flow laws of intensity and continuity in relation to earth’s surface gravity

With the help of the physical laws of flow, it is possible to describe the entire human blood circulation. However, this requires precise knowledge of the individual parameters. Within this, the determination of the flow rate included in the law of continuity is essential. Together with the data of the heart and circulation examination procedures, in order to establish the average human blood circulation, an intermediate velocity value must be selected, which is located in the middle between the two extreme velocities of the blood circulation. Another important factor from the point of view of the structure and operation of the model is the value of the earth's surface gravity. By finding the average flow speed value and using ‘g’, a torus-shaped circulation can be created, which can actually reflect the circulation conditions. By further refining the model, the pulmonary and systemic circulations can be separated and a ‘folded figure eight’ model can be formed. This realistically reflects the different sizes, flow and pressure conditions of the two blood circulations, as well as the work of the left and right sides of the heart.