Hydrodynamic Studies Research Articles

THE METHOD FOR IMPLEMENTING SEMANTIC INTEROPERABILITY OF FACTOGRAPHIC DATA OF OPERATIONAL DOCUMENTATION OF LARGE PRODUCTION SYSTEMS

The creation and operation of large production systems (LPS), consisting of a set of enterprises and organizations, characterized by their complex interaction, is one of the directions of industrial development in our country. The advantage of the LPS is to increase the efficiency of its functioning, build up scientific potential, and coordinate the enterprises and organizations that are part of it. The production activity of any enterprise is associated with solving the problems of making management decisions, which is based on the processing of exploitative factographic data. By the exploitative content of an enterprise, we mean significant information content for the process of its operation, which is stored in the form of an information resource (for example, an electronic document). Factographic data allow you to monitor the current state of the enterprise, to determine the strategic, tactical, exploitative goals and objectives of the enterprise, to develop well-grounded and timely management decisions. The processing of exploitative factographic data of operational content requires the involvement of additional resources for its processing, which is explained by the low formalizability of the exploitative content and the lack of implementation of semantic interoperability. Semantic interoperability is understood as “the ability of any information systems interacting in the process of communication to understand in the same way the meaning of the information they exchange”. Thus, the actual problem of the operation of large production systems is the implementation of the semantic interoperability of factual data of operational documentation, which will allow the use of a universal algorithm for their processing. The main directions of approaches to the implementation of semantic interoperability are considered and their shortcomings are identified. An approach to the implementation of semantic interoperability based on the use of semistructure of exploitative factual content of electronic documents is proposed. As part of the work, a practical example of the implementation of the proposed approach is given on the example of processing the results of hydrodynamic studies of gas wells. A universal method of marking factographic data in the content of electronic MS Word documents by means of their semistructure models is proposed, which implements support for their semantic interoperability and automated processing for all MS Word document formats implemented on the basis of XML technology.

Fluid Pressure Dynamics in a Hydraulic Fracture during Transient-Well-Operation Modes

At present, hydraulic fracturing is one of the most effective methods for intensifying hydrocarbon production. The paper describes the transient-well-operation modes of the well, establishes a connection between the changing fluid flow in the well and the pressure in the fracture and reservoir. With this purpose, a solution is found to the integro-differential equation that describes the change in pressure in the hydraulic fracture with a known change in pressure in the well or at a given flow rate. Based on the bottomhole pressure change data for a short-term pump operation that maintains a constant flow rate and subsequent pump shutdown (Π-shaped flow rate change), it is convenient to determine the characteristics of a hydraulic fracture using the formulae proposed in the paper. The results of the work can be used in hydrodynamic studies of wells.

Hydrodynamics and Sediment Modelling for a Fishery Harbour in Konkan Region of Maharashtra, India

Coastal regions are among the most important places for urban development and industrial expansion. However, the system is active and it must be well examined before any infrastructure is planned, to avoid harm from natural processes like degradation, sedimentation, and sometimes sea-generated natural disasters. Numerical modelling of the coast to forecast the area’s natural parameters is an important technique for assessing these systems. Coastal regions are of critical importance to most of the world’s citizens with a significant bearing on economic activities. In the present study, a well-calibrated mathematical model of Vengurla, Maharashtra, has been developed using MIKE 21 flexible mesh software, with the latest prototype data and also carried out 2-D hydrodynamic studies for the proposed 500m breakwater and approach channel. The simulated model will be tangled with the sediment transport model to ascertain the likely pattern of siltation in the area. After studying the Hydrodynamic model, it was observed that in existing conditions, currents varied in the range of 0-0.02 m/sec inside the Vengurla creek and 0-0.15 m/sec in the seawater and currents under the proposed condition varied in the range of 0-0.029 m/sec inside the Vengurla creek and 0-0.22 m/sec in the seawater. No severe circulation or eddies were observed near the beach area in the existing condition as well as in the proposed condition, hence no siltation has occurred in that area. From the sediment model, it was observed that there is not much siltation/erosion after the construction of the proposed breakwater and deepening of the approach channel.

Hydrodynamic study of internal circulation inside microreactor for transesterification process

Microreactors are important devices used in the field of process intensification. The use of microreactors offers several advantages, such as larger surface area to volume ratio, increasing mass and heat transfer rates, easy control of reagents and reactions, as well as easy scalability. The hydrodynamics within the microreactor produce several flow patterns, such as annular, parallel, and slug flow. Slug flow is of particular interest as it allows for greater mass transfer as mass transfer occurs not only at the interface but also within the internal circulations of the slug. The aim of this research was to investigate the formation of these internal circulations of these slugs under different parameters and how these internal circulations affect the mass transfer of the process. An inverted microscope was used to visualize the flow patterns of the internal circulation with the help of dye or small particles. The slug shape remains relatively unchanged at different catalyst concentrations, flowrates and oil-to-methanol ratios, and the internal circulations formed in the slugs remain fully formed regardless of the slug size. It can be said that process intensification of transesterification utilizing microreactor is a viable option and can be further improved with optimal parameters.

Determination the initial value and change behaviour of the reservoir permeability via two field measurements

The paper proposes a technique for interpreting the results of hydrodynamic studies of volatile and non-volatile oil wells at two steady-state regimes in order to determine the initial value and coefficient of variation in effective permeability of the reservoir. It is developed based on a binary filtration model, where the hydrocarbon system is represented as consisting of two pseudocomponents and two phases, between which mass transfer of hydrocarbons takes place. The proposed methodology requires well flow rates measured at two different steady-state well conditions for two different reservoir pressures and thermodynamic data of the hydrocarbon system at reservoir conditions. The methodology has been validated using examples of hypothetical volatile and non-volatile oil reservoirs at different rock deformation ratios and for nondeformable reservoirs. It has also been tested under different development stages and measurement conditions. For this purpose, a computer simulation of the oil reservoir depletion process was carried out, the results of which were used as well test data. Satisfactory accuracy and reliability of the outlined approach has been established. As deviations of calculated values of required parameters from their actual values did not exceed 8%.

Effects of a rough surface vortex breaker hydrocyclone on the separating capacity of heterogeneous fluid systems

This paper considers the issue of heterogeneous system separation efficiency under the action of centrifugal forces working in hydrocyclones. The main problem with these apparatuses is related to vortex forming. The paper describes the negative effects of vortexes on the heterogeneous medium separation process. A hydrocyclone design was developed and described, which improves the hydrocyclone separation capacity. This design introduces a vortex breaker. Furthermore, vortex formation can be eliminated or minimized by providing the vortex breaker with a rough surface. To determine the separation efficiency and the adequacy of the proposed solution, hydrodynamic computer simulation and experimental studies were conducted. Solidworks Flow Simulation software was used for hydrodynamic computer simulation. To check the medium separation degree, an experimental study was conducted showing improvement of the hydrocyclone separation capacity efficiency by 3% in the developed apparatus compared to conventional hydrocyclone designs. Keywords: hydrocyclone; separation; separating capacity; vortex breaker; heterogeneous system; oil preparation; hydrodynamics.

CFD study of the reactive gas-solid hydrodynamics in a large-scale catalytic methanol-to-olefin fluidized bed reactor

Lacking the understanding of multiphase flow in the fluidized bed methanol-to-olefin (MTO) process hinders the reactor design, operation, and optimization. Accordingly, a three-dimensional multiphase particle-in-cell model is established to study hydrodynamics and thermochemical characteristics during the MTO process in a fluidized bed reactor. After model validation, the influences of several critical operating parameters on reactor performance are discussed. The results show that particles in the medium part and freeboard of the reactor have heterogeneous velocity, temperature, and heat transfer coefficient (HTC) distributions. Thermal quantities of gas and solid phases are uniformly distributed in the medium part and freeboard of the reactor. The particle-averaged HTC under ranges from 60 to 120 W/(m2·K). Increasing wall temperature enlarges the particle HTC due to the enhanced exothermic reactions. Decreasing the particle diameter gives rise to a larger particle HTC. The vertical particle dispersion coefficient (Dz) is in the range of 0.01 m2/s to 0.03 m2/s. Methanol converts into olefin in a short period. Increasing methanol to catalyst ratio and wall temperature increases olefin including C2H4, C3H6, C4H8, and C5H10, and promotes the gas thermal properties. Particles with multi-sizes show a better MTO conversion performance than those with mono-sizes regarding the particle HTC and gas products.

Application of the Correlation Measurement Method for Reconstructing of the Velocity Profile with Spatial and Temporal Discretization in Studies of the Hydrodynamics of Turbulent Flows Based on the Matrix Conductometry Method

The correlation method for measuring of the coolant fl rate is used in the operation of nuclear power plants and is widespread in research practice including study of turbulent fl hydrodynamics. However the question of its applicability and possibilities in studies using the matrix conductometry method remains open. Earlier the algorithm for determining of the correlation fl rate using a conductometric measuring system was highlighted and the error of the results obtained was estimated and the dependence of the influence of noise and the time of data collection on the reliability of results was investigated. These works were carried out using two independent mesh sensors and the issue of the resolution of local velocity components was not covered. The purpose of this work was to test the correlation method for measuring velocity with temporal and spatial sampling using two-layer mesh conductometric sensors.As the result velocity cartograms were obtained over the cross-section of the experimental model with quasi-stationary mixing and the value of the average flow rate is in good agreement with the values obtained from the standard flow meters of the stand. Also measurements were carried out at a non-stationary setting of the experiment and realizations of the flow rate and velocity components of the flow at the measuring points were obtained.Analysis of the obtained values allows to conclude about the optimal data collection time for correlation measurements, as well as the reliability of results.

Foreflipper and hindflipper muscle reconstructions of Cryptoclidus eurymerus in comparison to functional analogues: introduction of a myological mechanism for flipper twisting.

BackgroundPlesiosaurs, diapsid crown-group Sauropterygia, inhabited the oceans from the Late Triassic to the Late Cretaceous. Their most exceptional characteristic are four hydrofoil-like flippers. The question whether plesiosaurs employed their four flippers in underwater flight, rowing flight, or rowing has not been settled yet. Plesiosaur locomotory muscles have been reconstructed in the past, but neither the pelvic muscles nor the distal fore- and hindflipper musculature have been reconstructed entirely.MethodsAll plesiosaur locomotory muscles were reconstructed in order to find out whether it is possible to identify muscles that are necessary for underwater flight including those that enable flipper rotation and twisting. Flipper twisting has been proven by hydrodynamic studies to be necessary for efficient underwater flight. So, Cryptoclidus eurymerus fore- and hindflipper muscles and ligaments were reconstructed using the extant phylogenetic bracket (Testudines, Crocodylia, and Lepidosauria) and correlated with osteological features and checked for their functionality. Muscle functions were geometrically derived in relation to the glenoid and acetabulum position. Additionally, myology of functionally analogous Chelonioidea, Spheniscidae, Otariinae, and Cetacea is used to extract general myological adaptations of secondary aquatic tetrapods to inform the phylogenetically inferred muscle reconstructions.ResultsA total of 52 plesiosaur fore- and hindflipper muscles were reconstructed. Amongst these are flipper depressors, elevators, retractors, protractors, and rotators. These muscles enable a fore- and hindflipper downstroke and upstroke, the two sequences that represent an underwater flight flipper beat cycle. Additionally, other muscles were capable of twisting fore- and hindflippers along their length axis during down- and upstroke accordingly. A combination of these muscles that actively aid in flipper twisting and intermetacarpal/intermetatarsal and metacarpodigital/metatarsodigital ligament systems, that passively engage the successive digits, could have accomplished fore-and hindflipper length axis twisting in plesiosaurs that is essential for underwater flight. Furthermore, five muscles that could possibly actively adjust the flipper profiles for efficient underwater flight were found, too.

ASYMMETRICAL WATER IMPACT OF TWO-DIMENSIONAL WEDGES WITH ROLL ANGLE WITH MULTI-MATERIAL EULERIAN FORMULATION

A hydrodynamic study on the asymmetrical water impact of two-dimensional wedges with roll angle is presented. The slam induced loads on the wedges entering calm water with both vertical and horizontal velocities are predicted based on the explicit finite element method. The effects of the horizontal impact velocity and the roll angle are investigated through the predicted results of pressure distribution, pressure variation during the water entry and total impact force, which are also compared with analytical formulations and other numerical calculations. The present method gives reasonable predictions, compared to the numerical and analytical results.

NON-DIMENSIONALISATION OF LATERAL DISTANCES BETWEEN VESSELS OF DISSIMILAR SIZES FOR INTERACTION EFFECT STUDIES

To date, most of the hydrodynamic interaction studies between a tug and a ship during ship assist manoeuvers have been carried out using model scale investigations. It is however difficult to establish how well results from these studies represent full scale interaction behaviour. This is further exacerbated by the lack of proven methodologies to non- dimensionalise the relative distances between the two vessels, enabling the comparison of model and full scale interaction effect data, as well as between vessels of dissimilar size ratios. This study investigates a suitable correlation technique to non-dimensionalise the lateral distance between vessels of dissimilar sizes, and a scaling option for interaction effect studies. It focuses on the interaction effects on a tug operating around the forward shoulder of a tanker at different lateral distances during ship assist operations. The findings and the non-dimensioning method presented in this paper enable the interaction effects determined for a given ship-to-tug ratio to be used to predict the safe operational distances for other ship-to-tug ratios.

Shapes’ optimisation using numerical naval hydrodynamics of a Ro-Ro double ferry with electric propulsion to cross the Danube

One of the crucial problems of the 21st century is pollution. Regarding a low carbon footprint, thorough research efforts are being made to minimise fuel gas emissions. Ships, through the powers established for propulsion and the fossil fuels used, are some of the most toxic human inventions. Scientist in many European countries and beyond are developing studies either to reduce emissions from propulsion engines or to design body shapes of ships with low forward resistance and to find electric propulsion solutions. This paper carries out studies of naval hydrodynamics to find body shapes that generate the lowest resistance to advance. Thus, using hydrodynamic observations and with the help of the NUMECA calculation program, two different hulls are studied in order to establish the optimal shape with the lowest forward resistance. Furthermore, acknowledging the limited aquarium of the inland waters, an important aspect to approach is the size of the waves as well as their length. In order not to cause damage to existing shores and facilities, the waves produced by the floating body must have minimum heights and wavelengths.

A critical review on early-warning electrochemical system on microbial fuel cell-based biosensor for on-site water quality monitoring

The microbial fuel cell (MFC) sensor is a very promising self-powered self-sustainable system for early warning water quality detection. These sensors are cost-effective, biodegradable, compact in design, and portable in nature are favorable for real-time in situ water quality monitoring. This review represents the mechanism action behind the toxicity detection, optimization strategies, process parameters, role of biofilm, the role of external resistance, hydrodynamic study, and mathematical modeling for improving the performance of the sensor. Additionally, the techno-economic prospect of this MFC-based sensor and its challenges, limitations are addressed to make it economically more favorable for commercial use. The future direction is also explored based on the sensor's disadvantages and limitations. Comprehensively, this review covered all the possible directions of MFC sensor fabrication, their application, recent advancement, prospects challenges, and their possible solutions.

From Adsorbent to Photocatalyst: The Sensitization Effect of SnO2 Surface towards Dye Photodecomposition.

Semiconductor photocatalysis is considered one of the most promising technologies for water purification from toxic organic dyes. However, to reliably evaluate the possibility of using a given material as a photocatalyst, it is crucial to investigate not only the photocatalytic activity but also its affinity towards various dyes and reusability. In this work, we studied the adsorptive/photocatalytic properties of hollow-spherical raspberry-like SnO2 and its SnO2/SnS2 heterostructures that were obtained via a chemical conversion method using three different concentrations of a sulfide precursor (thioacetamide). The adsorptive/photocatalytic properties of the samples towards cationic rhodamine B (RhB) and anionic indigo carmine (IC) were analyzed using uncommon wall zeta potential measurements, hydrodynamic diameter studies, and adsorption/photodecomposition tests. Moreover, after conducting cyclic experiments, we investigated the (micro)structural changes of the reused photocatalysts by scanning electron microscopy and Fourier-transform infrared spectroscopy. The obtained results revealed that the sensitization of SnO2 resulted not only in the significantly enhanced photocatalytic performance of the heterostructures, but also completely changed their affinity towards dyes. Furthermore, despite the seemingly best photocatalytic performance, the sample with the highest SnS2 content was unstable due to its (micro)structure. This work demonstrates that dye adsorption/desorption processes may overlap the results of cyclic photodecomposition kinetics.

Regional Crustal Vertical Deformation Driven by Terrestrial Water Load Depending on CORS Network and Environmental Loading Data: A Case Study of Southeast Zhejiang.

Monitoring regional terrestrial water load deformation is of great significance to the dynamic maintenance and hydrodynamic study of the regional benchmark framework. In view of the lack of a spatial interpolation method based on the GNSS (Global Navigation Satellite System) elevation time series for obtaining terrestrial water load deformation information, this paper proposes to employ a CORS (Continuously Operating Reference Stations) network combined with environmental loading data, such as ECMWF (European Centre for Medium-Range Weather Forecasts) atmospheric data, the GLDAS (Global Land Data Assimilation System) hydrological model, and MSLA (Mean Sea Level Anomaly) data. Based on the load deformation theory and spherical harmonic analysis method, we took 38 CORS stations in southeast Zhejiang province as an example and comprehensively determined the vertical deformation of the crust as caused by regional terrestrial water load changes from January 2015 to December 2017, and then compared these data with the GRACE (Gravity Recovery and Climate Experiment) satellite. The results show that the vertical deformation value of the terrestrial water load in southeast Zhejiang, as monitored by the CORS network, can reach a centimeter, and the amplitude changes from −1.8 cm to 2.4 cm. The seasonal change is obvious, and the spatial distribution takes a ladder form from inland to coastal regions. The surface vertical deformation caused by groundwater load changes in the east–west–south–north–central sub-regions show obvious fluctuations from 2015 to 2017, and the trends of the five sub-regions are consistent. The amplitude of surface vertical deformation caused by groundwater load change in the west is higher than that in the east. We tested the use of GRACE for the verification of CORS network monitoring results and found a relatively consistent temporal distribution between both data sets after phase delay correction on GRACE, except for in three months—November in 2015, and January and February in 2016. The results show that the comprehensive solution based on the CORS network can effectively improve the monitoring of crustal vertical deformation during regional terrestrial water load change.

Continuum and Molecular Dynamics Studies of the Hydrodynamics of Colloids Straddling a Fluid Interface

Colloid-sized particles (10 nm–10 μm in characteristic size) adsorb onto fluid interfaces, where they minimize their interfacial energy by straddling the surface, immersing themselves partly in each phase bounding the interface. The energy minimum achieved by relocation to the surface can be orders of magnitude greater than the thermal energy, effectively trapping the particles into monolayers, allowing them freedom only to translate and rotate along the surface. Particles adsorbed at interfaces are models for the understanding of the dynamics and assembly of particles in two dimensions and have broad technological applications, importantly in foam and emulsion science and in the bottom-up fabrication of new materials based on their monolayer assemblies. In this review, the hydrodynamics of the colloid motion along the surface is examined from both continuum and molecular dynamics frameworks. The interfacial energies of adsorbed particles is discussed first, followed by the hydrodynamics, starting with isolated particles followed by pairwise and multiple particle interactions. The effect of particle shape is emphasized, and the role played by the immersion depth and the surface rheology is discussed; experiments illustrating the applicability of the hydrodynamic studies are also examined.

Inca water channel flow analysis based on 3D models from terrestrial and UAV laser scanning at the Chachabamba archaeological site (Machu Picchu National Archaeological Park, Peru)

The Chachabamba archaeological site contains a unique water complex erected and modified by the Incas. Based on archaeological investigations within the ceremonial sector, it has been established that the function of this water complex was strictly ceremonial. Moreover, hydrodynamic studies of the water supply canals have verified the previous findings. Due to the complex characteristics of the site, which is largely overgrown by dense vegetation, we employed a methodology not previously applied in the region. Three-dimensional documentation techniques were used to produce hydrodynamic analyses of the site, which facilitated the preparation of appropriate models that are key to understanding the function of the entire water system.

Accumulation of Tetrahymena pyriformis on Interfaces.

The behavior of ciliates has been studied for many years through environmental biology and the ethology of microorganisms, and recent hydrodynamic studies of microswimmers have greatly advanced our understanding of the behavioral dynamics at the single-cell level. However, the association between single-cell dynamics captured by microscopic observation and pattern dynamics obtained by macroscopic observation is not always obvious. Hence, to bridge the gap between the two, there is a need for experimental results on swarming dynamics at the mesoscopic scale. In this study, we investigated the spatial population dynamics of the ciliate, Tetrahymena pyriformis, based on quantitative data analysis. We combined the image processing of 3D micrographs and machine learning to obtain the positional data of individual cells of T. pyriformis and examined their statistical properties based on spatio-temporal data. According to the 3D spatial distribution of cells and their temporal evolution, cells accumulated both on the solid wall at the bottom surface and underneath the air–liquid interface at the top. Furthermore, we quantitatively clarified the difference in accumulation levels between the bulk and the interface by creating a simple behavioral model that incorporated quantitative accumulation coefficients in its solution. The accumulation coefficients can be compared under different conditions and between different species.

Hydrodynamic evaluation of a filter bed of porous material from stratified sedimentary rocks for the removal of turbidity in surface waters

In this study, the behavior of a filter bed of stratified sedimentary rocks was evaluated through the analysis of turbidity removal efficiency and head losses. Two types of sands were used as materials, fine and medium, as well as crushed limestone. The materials were characterized to determine the average particle diameter, porosity, and permeability coefficient, obtaining respectively 0.17 mm, 0.39, and 1 × 10−3 cm/s for fine sand, 0.33 mm, 0.41, and 3 × 10−3 cm/s for medium sand, and 1.26 mm, 0.45, and 1 × 10−2 cm/s for crushed limestone. Hydrodynamic analyses of the clean filter under conditions of rapid filtration were carried out, by which the different rates of filtration to be used in each experiment were determined, establishing a direct correlation between the rate of filtration and the thickness of the bed; in this way, it was possible to determine the maximum bed thickness that could be used to maintain a rate of rapid filtration higher than 120 m/day. A hydrodynamic study with synthetic turbid water prepared at 8 NTU using tap water and bentonite was also carried out. Total head losses and turbidity removal were studied for each material at a rate of 153 m/day with removal efficiencies of 93.7% for medium sand with a loss of 23 cm and 67.8% for limestone with a loss of 4.5 cm and a rate of 389 m/day. It is recommended to use the medium sand and limestone type material for use in surface water filtration processes.

Numerical and experimental evaluation of the general performance in a modular electrochemical reactor and its feasibility for electro-chlorination purposes: Effect of the different electrode assembly configurations

Evaluation of electrochemical reactors consisting of different electrode assemblies, stacks, or modular units, by the employing of computational techniques and its comparison with experimental data is desirable for its applications and scaling up for electrochemical processes like the mediated electro-chlorination. This work aimed to evaluate the effect of three different electrode configurations (flat, interspersed, and C-stack assemblies) on the general performance of a homemade modular reactor, based on former ElectroSyn design with an improved inlet-outlet system, through studies of hydrodynamics, electrical characteristics, and mass transfer. Additionally, a secondary potential-current distribution study was carried out to evaluate the feasibility of different electrode configurations tested for the electro-chlorination process, that can be applied mainly for environmental purposes like mediated oxidation of organic pollutants and disinfection by the production of active chlorine species.From the hydrodynamic study, velocity profiles and RTD curves obtained in all electrode configurations tested, suggest that the flat electrode configuration exposes a low fluid dispersion and resistance than the other configurations, because of the diminishing of the high-velocity zones and by its higher cross-sectional area, which was confirmed by the pressure drop measurements. On the other hand, calculation of primary and secondary current distribution suggests that the presence and modification of edge effect in the different configurations tested generate strong non-uniformities in the electrode corners and the reactor walls, which could affect the distribution of reaction rate during the mass transport evaluations. Also, the secondary potential-current distribution study indicates that the flat and C-stack configurations are the more electrical feasible configurations (since the effect of the flow field and mass transfer was not taken into account) to be applied in the electro-chlorination process.