Fluid Separation Research Articles

WATER AND OIL AUTOMATIC SEPARATION SYSTEM USING FUZZY CONTROL

This paper presents the design of a water and oil separation system as a contribution to reduce the problem of contamination of water in domestic and industrial sewage. The project consists of improvements in level detection in an automatic separation tower and in the use of the Fuzzy control. The main objective is to design a controller based on the values of the levels and increase the reliability in the process of separation of the fluids. The validation of the controller is obtained through simulation in MATLAB engineering software and the improvements applied are corroborated according to the results observed in the separation process. Satisfactory results show increased reliability in the fluid separation process, leaving the minimum fluid within the reservoir.

Utilization of guide vanes to concentrate flows to the blade and block vortex to improve the power factor of savonius wind turbine

Simple design Savonius vertical-axis wind turbine can generate energy at low wind speed from any direction. However, its large static torque has a low power factor. Therefore, an innovation was made by providing 16 guide vanes around the shaft outside the blade with the angle is about 45° to a radial line. The specialty of guide vanes is that , they are able to concentrate the wind flow toward the turbine blade from any direction. The fluid motion around the turbine blade that produces torque on the turbine shaft was analyzed utilizing the Computational Fluid Dynamics (CFD) simulation and then verified by tracking actual fluid motion strings of threads attached on each side of the turbine blade. The result shows that without guide vanes the wind flow around the turbine blade generates vortex on the blade and Karman vortex at the downstream. These vortexes descend effectively kinetic energy in the wind flow so that the mechanical energy on the turbine shaft becomes small. At a certain blade position, the vortex becomes stronger and the fluid separation from the blade surface becomes thicker. The stronger vortex tends to descend stronger fluid kinetic energy while the thicker separation tends to reduce the lift on the blade. Consequently, these two flow conditions tend to produce negative torque. Installing guide vanes around the blade, the wind flows are concentrated by the guide vanes to the turbine blade, which effectively reduces vortex around the blade and blocks large vortex outside the guide vanes downstream. Flow separation is suppressed by the concentrated flow producing larger lift. As a result, the power factor increases by 61.6 %. This huge increase in power factor is achieved when the wind speed is 5 m/s though a stable turbine rotation is achieved at a lower speed

Enhancing the Supersonic Gas Separation operating envelope through process control strategies of the feed conditioning plant for offshore CO2 removal from natural gas

Centrifugal Fluid Separation technology, in particular Supersonic Gas Separation (SGS), is one of the potential technologies considered for offshore CO2 capture. SGS has advantages in terms of CAPEX, hydrocarbon losses, footprint, tonnage and power requirement compared to conventional solutions such as membrane. Even though the technology has been developed since 1989, the applications are limited to mainly dehydration and hydrocarbon dew pointing. For CO2 separation from natural gas, substantial development works are needed prior to the field application as there are a lot of uncertainties in the feed conditions to be tackled. In particular, the stringent requirements of cryogenic temperature, high pressure and inlet CO2 composition of its feed require a robust feed conditioning process plant. For a relatively new technology such as SGS for CO2 removal application, it is crucial to investigate and assess the variations of feed and process conditions i.e. temperature, pressure and gas compositions prior to being applied at actual field, as these will impact the CO2 separation performance inside the separator. Hence, this paper investigates the control strategies for the SGS feed conditioning plant subjected to ±15 % disturbances in temperature and pressure, and ±5 mol% variations in feed CO2 composition. Results show that effective disturbances elimination in the first flash separator of the feed conditioning plant is crucial in minimizing the impact to the SGS operation. A comparative study reveals that standard PID controller performs significantly better in disturbance rejection than Model Predictive Control.

Application of NEAT for the simulation of liquid–liquid extraction processes with poorly specified feeds

AbstractThe conceptual design of fluid separation processes is particularly challenging if the considered mixtures are poorly specified, since classical thermodynamic models cannot be applied when the composition is unknown. We have recently developed a method (NEAT) to predict activity coefficients in such mixtures. It combines the thermodynamic group contribution concept with the ability of NMR spectroscopy to quantify chemical groups. In the present work, we describe how NEAT can be applied to equilibrium stage simulations of liquid–liquid extraction processes with poorly specified feeds. Only a single 13C NMR spectrum of the feed is needed for predicting the distribution of a target component for different process parameters, such as temperature or extracting agent. The predictions from several test cases are compared to results that are obtained using the full knowledge on the composition of the feed and surprisingly good agreement is found.

Parametric Analysis for forming meso fractals from nanoparticle seeded resin in Hele Shaw cell

Development of meso and micro size fractal structures is required to mimic various biological systems for various functions. Meso and micro size fractal structures are fabricated by several processes in Engineering. A number of fluid flows are exhaustively analyzed and investigated in the direction of development of meso and micro fractal structures. Hele-Shaw flow is one of the flows which fabricated meso and micro structure. Formation of fractals in Hele-Shaw cell can be done by compressing fluid in two flat parallel plates and lifting of upper plate in the upward direction. Lifting velocity of the upper plate, a gap between the plates, and fluid properties viz. density, viscosity are the major parameters in the formation of fractal. This paper presents the characterization of the fluid, study and analysis of microfractals followed by a mathematical model. The characterization of the fluid consists of photopolymer seeded with the nanopowder in the lifting plate of Hele-Shaw. The resin is prepared by mixing photoinitiator Benzoyl Ethyl Ether (BEE), Hexanediol Diacrylate (HDDA) added with ceramic nanopowder. Through the design of the experiment, micro fractal growth is observed and analysed. The fractals growth controlling parameters viz. gap between plates, velocity causes fluid separation are varied through the experimental setup. Effect of variation in viscosity set by varying loading fraction of seeded ceramic nanoparticles in a resin is observed for formation of fractals. Effect of process parameters on formation and growth of fractals is studied and presented. A dimensionless model of fractal growth is presented to analyse the effect of various parameters. Experimental methodology introduced a new style for the formation of controlled fractals or to imitate different meso and micro fractals available in nature or living things.

Airfoil shaped pin-fin heat sink: Potential evaluation of ferric oxide and titania nanofluids

Miniaturization of devices poses many problems for the manufacturing industry. To maintain the temperature of such high heat generating devices hybrid cooling via mini-channel heat sinks in combination with nanofluid is one of the potential cooling techniques. Airfoil pin-fins performed well due to delayed separation of fluid that ensured the maximum interaction of coolant with the walls of heat sink. The main purpose of present study is to analyze the hydrothermal performance of airfoil shaped pin-fin heat sink employing nanofluids of ferric oxide (Fe2O3) and titania (TiO2), also compare the results with base fluid (distilled water). The study was conducted by varying the heating power and Reynolds number. Maximum augmentation in average Nusselt number of 14.5% and 15.89% was found for TiO2-water and Fe2O3-water nanofluids respectively with a particle concentration of 0.01 vol% at 25 W as compared to distilled water. In addition, a maximum enhancement of 42.46% was observed in pumping power for Fe2O3 while it was 30.5% for TiO2 nanofluid.

Numerical simulation of CO2 and dye separation for supercritical fluid in separator

Separator, as one of the key components in supercritical CO2 dyeing apparatus, shows the function of separating CO2 and dyes, thus affecting the reutilization of CO2 and the subsequent dyeing production. In this study, pressure drop and separation efficiency of the separator were investigated by employing the flow field analysis software FLUENT. Fluid area calculation of the separator was conducted using Reynolds stress model as the turbulence model and SIMPLEC algorithm. Moreover, separation efficiency of CO2 gas and dyes in the separator was determined by employing Discrete phase model as the calculation model of dye particle phase. Numerical results showed that the total pressure drop of the separator increased from 1.43 Pa to 122.70 Pa with the inlet flow rate of CO2 increased from 50 L/h to 2000 L/h. The total separation efficiency of the separator improved significantly from 4.35% to 38.22% when the inlet flow rate increased from 100 L/h to 2000 L/h.

Development of a valveless piezoelectric pump with vortex diodes

The cut-off capacity of the fluid diode determines the output performance of the valveless piezoelectric pump with flow resistance difference tubes. In this study, a valveless piezoelectric pump with vortex diodes is proposed, which utilizes the vortex diodes as internal valves with no moving parts. The internal flow field is calculated for the vortex diode with different chamber diameter ratios. The largest impedance ratio of the structural parameters of the vortex diode is obtained from the calculation results. Then, different prototypes of the piezoelectric pumps with a diffuser/nozzle, Tesla tubes and vortex diodes are manufactured. The experimental results demonstrate that the output performance of the valveless piezoelectric pump with vortex diodes is better than those of the other pumps: the maximum flow rate of the valveless piezoelectric pump with vortex diodes reaches 9.86 g min−1 at a driving voltage of 200 V with a driving frequency of 49 Hz, and the maximum output pressure of the piezoelectric pump reaches 340 Pa. In addition, the valveless piezoelectric pump with vortex diodes achieves a good carrying capacity, which is suitable for transmission of high-viscosity liquid. Flow field analysis demonstrates that strong vortex motion and strong shear forces exist near the center of the vortex chamber, which provide the basis function for fluid mixing and fluid separation.

Passage of a Taylor Bubble through a Stratified Liquid–Liquid Interface

The bypass of an air bubble through a liquid–liquid interface may produce rich fluidic physics. Air injection is a passive technique to mix the contents of the two separated fluids and provides an effective heat and mass transfer intensification by increasing the interfacial area between them. Entrainment of heavier fluid into the lighter fluid at atmospheric and isothermal conditions has been simulated by using the VOF (volume of fluid) technique mimicking a Taylor bubble bypass through a horizontal liquid–liquid interface of water and polydimethylsiloxane (PDMS) solution. The migration of a Taylor bubble across the interface is completed through five different stages, namely, approach, encapsulation, de-encapsulation, entrainment, and detrainment. The bubble kinematics, entrained water volume, microdroplets formation, and film thinning characteristics have been studied in detail. The marginal pinch-off mechanism for the rupturing of the entrapped water film has been observed due to the presence of the s...

Research on the Effects of Nonsmooth Surfaces on Backward-facing Step Flow

To achieve the purpose of backward-facing step flow control, a passive control approach, which consists in introducing nonsmooth structures in solid walls, is applied to the upstream of the backward-facing step. Based on STAR CCM+ software, the standard k-ε turbulence model was established to simulate flow characteristics of the right angle step, fillet step and nonsmooth fillet step. The introduction of the nonsmooth surface leads to a significant reduction in recirculation region length (17.5%) and a decrease in downstream wall pressure coefficient. According to the analysis of separation point position and turbulent kinetic energy, the delay of separation point and the enhancement of momentum exchange are the main reasons for the success of flow control. Compared with the right angle step, the delay of flow separation of the fillet step leads to a reduction in step expansion ratio (ER), and the existence of the nonsmooth structure enhances the turbulent kinetic energy at the fluid separation points and the momentum mixing at the downstream of the step, thus reducing the reattachment length and the downstream wall pressure coefficient.

Embriología del sistema ventricular cerebral

El Sistema Ventricular Cerebral se desarrolla de forma paralela al resto del Sistema Nervioso Central, facilitando la circulación del Líquido Cefalorraquídeo, desde su separación del líquido amniótico a nivel embrionario. Este desarrollo es necesario para entender correctamente la anatomía ventricular y facilitar el abordaje para patologías intraventriculares. El objetivo de esta revisión es reconocer los puntos más importantes en la embriología ventricular para facilitar el aprendizaje de la anatomía quirúrgica ventricular.

Two-fluid simulations of waves in the solar chromosphere

Waves and shocks traveling through the solar chromospheric plasma are influenced by its partial ionization and weak collisional coupling, and may become susceptible to multi-fluid effects, similar to interstellar shock waves. In this study, we consider fast magneto-acoustic shock wave formation and propagation in a stratified medium, that is permeated by a horizontal magnetic field, with properties similar to that of the solar chromosphere. The evolution of plasma and neutrals is modeled using a two-fluid code that evolves a set of coupled equations for two separate fluids. We observed that waves in neutrals and plasma, initially coupled at the upper photosphere, become uncoupled at higher heights in the chromosphere. This decoupling can be a consequence of either the characteristic spatial scale at the shock front, that becomes similar to the collisional scale, or the change in the relation between the wave frequency, ion cyclotron frequency, and the collisional frequency with height. The decoupling height is a sensitive function of the wave frequency, wave amplitude, and the magnetic field strength. We observed that decoupling causes damping of waves and an increase in the background temperature due to the frictional heating. The comparison between analytical and numerical results allows us to separate the role of the nonlinear effects from the linear ones on the decoupling and damping of waves.

Deciding the Effective Position of Fuel Injector using Cfd

We are going to test the fluid flow of fuel injector by the process of computational fluid dynamics (CFD). Fluid separator is a mechanical device which helps two or more fluid to separate from a mixture. Fluid separator has its application in many pharmaceutical and automobile industries. Fluid separator had made the most promising device in the industry. Most of the modification has been made in the design of the fuel injector with respect to geometry and thermal design. In a CFD, the examination of fluid flow in accordance with its physical properties such as velocity, temperature, density and viscosity are obtained. The study shows the best performance of fuel injector with respect to shape and flow rates. The purpose of this report is to corelate various design of injector in the industry. In this Paper we can find out the effective position of the fuel injector using CFD.

A local thermal non-equilibrium integral analysis for forced convective thermal boundary development in a channel filled with a fluid-saturated porous medium

An integral solution procedure has been developed to describe the entire evolution of the thermal boundary layer in a channel filled with a fluid-saturated porous medium. The upper and lower walls are heated under a constant heat flux condition, and local thermal nonequilibrium is assumed to apply. The development of the thermal boundary layer in this channel is divided into three distinctive regions, namely, the entrance, transition and the nearly fully-developed regions, in which separate fluid and solid phase thermal boundary layers develop near heated walls with different growth rates. In this integral analysis, each region is considered in terms of the interactions between the fluid and solid thermal boundary layers; this eventually yields a set of algebraic equations for the easy and accurate estimation of the local Nusselt number. The solutions thus obtained for the three regions are combined to reveal the entire development of the local Nusselt number from the entrance to fully-developed stage. This analytic procedure, for the first time, reveals a complete region map showing the locations of the transition from one region to another, and these depend on the Biot number, the thermal conductivity ratio and the Graetz number in a complex manner.

Automated Cow Manure Tiles Maker

Bricks are widely considered as one of the longest-lasting and strongest building material. Recently it is also used as aesthetic items that are commonly used on gardens and garages. On the other hand, cow manure has given a decent amount of attention in the recent times due to the various applications that may be utilized for the society. This research is a microcontroller-based machine which focuses on cow manure to garage tile conversion to provide an alternative process in the creation of said tiles. It is an applied research designed to utilize electronic and mechanical processes to manipulate the given input to a specific end product. The device’s design starts with two receptacles which are connected to separate grinder, which then inputted materials will be weighted onto a load cell. This in turn will pass through a mixer, which also accepts fluid input from three separate fluid reservoirs filled with differently colored fluids. The mixture then finally comes to a chosen designated molder. The entire process will be controlled by the user through LCD screen to display user options. After the process the device will output a designed and colored garage tile. This device was developed in the hopes of finding an alternative material other than clay and soil from making garden tiles and also in automating and further improving the time for manufacture. The speed of mixing and molding cow manure as well as the compressive strength of the produced tiles were considered and passed under the set standard. The evaluation results based on functionality, reliability, usability, efficiency and maintainability of the Automated Cow Manure Tiles Maker was 3.48 which signify a neutral acceptance of the respondents.

Serum interleukin 6 could be a valuable initial diagnostic tool in prosthetic knee joint infections.

Accurate preoperative diagnosis of prosthetic joint infection (PJI) in the absence of obvious clinical signs or laboratory findings is challenging. Interleukin 6 (IL-6) has been proposed as an infection marker but supportive data are limited. We studied the diagnostic utility of serum IL-6 in infected total knee arthroplasty (TKA). A prospective cohort study was done in 52 patients (59 knees) with a painful TKA. The abnormal limits for serum IL-6, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), synovial fluid white cell counts (WBC) and synovial fluid neutrophils (PMN) were determined from receiver operating characteristic curves. An infection was defined as the presence of sinus tract or positive culture > two separate tissue or fluid samples. We utilized Mann-Whitney test, Spearman's correlation and Fischer's exact test to determine the sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy of serum IL-6. The optimal threshold concentration of serum IL-6 was 9.14pg/ml. Independently, this yielded a sensitivity, specificity and NPV of 81%, 63% and 85%, respectively, and when combined with synovial fluid WBC, values were 100%, 90%, 100%, respectively. The sensitivity and specificity of ESR (70%, 63.6%), CRP (66.7%, 66.7%), synovial WBC (66.7%, 81%) and synovial PMN (82.4%, 73.7%) were also calculated. Serum IL-6 levels strongly correlate with all markers in PJI. Serum IL-6 improves the diagnosis of PJI over existing methods, especially when combined with synovial fluid WBC. Its optimal usage is as an excellent screening test to rule out infected total knee arthroplasty. Diagnostic Level II.

Glacially Induced Hydromechanical Coupling in Shale May Have Caused Underpressured Water in the Eastern Michigan Basin Despite the Possible Presence of Gas Phase Methane

AbstractWhen glacial cycles occur above low‐permeability geologic formations, such as the shale and limestone units being considered for nuclear waste disposal in Canada, pressures may differ greatly from normal hydrostatic conditions. Although shale also often has the propensity to generate separate phase fluids like natural gas, it is largely uncertain how the processes that control this behavior might affect water pressure evolution during glacial loading cycles. Therefore, this study investigates the relationships among these system components via an example site that exhibits both a dramatic underpressure and potential evidence for gas phase methane in situ. A simple 1‐D representation of the site was constructed, and hydromechanical coupling during a glacial cycle was simulated with and without gas phase methane present. Results indicate that, while the presence of gas phase dampened the effects of the loading cycle due to its higher compressibility compared to water, it did not preclude underpressure development.

Microfluidic In-Flow Decantation Technique Using Stepped Pillar Arrays and Hydraulic Resistance Tuners.

Separating the particles from the liquid component of sample solutions is important for several microfluidic-based sample preparations and/or sample handling techniques, such as plasma separation from whole blood, sheath-free flow focusing, particle enrichment etc. This paper presents a microfluidic in-flow decantation technique that provides the separation of particles from particle-free fluid while in-flow. The design involves the expansion of sample fluid channel in lateral and depth directions, thereby producing a particle-free layer towards the walls of the channel, followed by gradual extraction of this particle-free fluid through a series of tiny openings located towards one-end of the depth-direction. The latter part of this design is quite crucial in the functionality of this decantation technique and is based on the principle called wee-extraction. The design, theory, and simulations were presented to explain the principle-of-operation. To demonstrate the proof-of-principle, the experimental characterization was performed on beads, platelets, and blood samples at various hematocrits (2.5%–45%). The experiments revealed clog-free separation of particle-free fluid for at least an hour of operation of the device and demonstrated purities close to 100% and yields as high as 14%. The avenues to improve the yield are discussed along with several potential applications.

Simulation of Dipole Vorticity Dynamics Colliding Viscous Boundary Layer at High Reynolds Numbers

The vorticity dynamics of a Lamb-like dipole colliding with flat boundaries are investigated for high Reynolds number flows by implementation of the lattice Boltzmann method (LBM). The standard LBM based on the single-relaxation-time collision model suffers from numerical instabilities at high Reynolds numbers. Herein, a regularized collision model is employed for the LBM to preserve the stability and accuracy of the numerical solutions at such flow conditions. The computations are performed for the normal collision of the dipole with the no-slip boundary for several Reynolds numbers in the range of . The results obtained based on the regularized lattice Boltzmann (RLB) method for the statistical flow characteristics like the vorticity field and enstrophy quantity of the dipole-wall collision problem are investigated. The present study demonstrates that the shear-layer instabilities near the wall are responsible for rolling-up of the boundary layer before it is detached from the surface for high Reynolds numbers. This detachment mechanism leads to a viscous rebound and formation of small scale vortices. The shear-layer vortices formed dramatically influence the flow evolution after the collision and result strong enhancement of the total enstrophy of the flow field. By comparing the present results with those of provided by other numerical solutions, it is also concluded that the RLB scheme implemented is robust and sufficiently accurate numerical technique in comparison with the flow solvers based on the Navier-Stokes equations for predicting the statistical features of separated fluid flows even at high Reynolds numbers.

Simulating the nonlinear interaction of relativistic electrons and tokamak plasma instabilities: Implementation and validation of a fluid model

For the simulation of disruptions in tokamak fusion plasmas, a fluid model describing the evolution of relativistic runaway electrons and their interaction with the background plasma is presented. The overall aim of the model is to self-consistently describe the nonlinear coupled evolution of runaway electrons (REs) and plasma instabilities during disruptions. In this model, the runaway electrons are considered as a separate fluid species in which the initial seed is generated through the Dreicer source, which eventually grows by the avalanche mechanism (further relevant source mechanisms can easily be added). Advection of the runaway electrons is considered primarily along field lines, but also taking into account the E×B drift. The model is implemented in the nonlinear magnetohydrodynamic (MHD) code jorek based on Bezier finite elements, with current coupling to the thermal plasma. Benchmarking of the code with the one-dimensional runaway electron code go is done using an artificial thermal quench on a circular plasma. As a first demonstration, the code is applied to the problem of an axisymmetric cold vertical displacement event in an ITER plasma, revealing significantly different dynamics between cases computed with and without runaway electrons. Though it is not yet feasible to achieve fully realistic runaway electron velocities close to the speed of light in complete simulations of slowly evolving plasma instabilities, the code is demonstrated to be suitable to study various kinds of MHD-RE interactions in MHD-active and disruption relevant plasmas.