Search results for: flow field analysis
11644 Numerical Simulation of unsteady MHD Flow and Heat Transfer of a Second Grade Fluid with Viscous Dissipation and Joule Heating using Meshfree Approach
Authors: R. Bhargava, Sonam Singh
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In the present study, a numerical analysis is carried out to investigate unsteady MHD (magneto-hydrodynamic) flow and heat transfer of a non-Newtonian second grade viscoelastic fluid over an oscillatory stretching sheet. The flow is induced due to an infinite elastic sheet which is stretched oscillatory (back and forth) in its own plane. Effect of viscous dissipation and joule heating are taken into account. The non-linear differential equations governing the problem are transformed into system of non-dimensional differential equations using similarity transformations. A newly developed meshfree numerical technique Element free Galerkin method (EFGM) is employed to solve the coupled non linear differential equations. The results illustrating the effect of various parameters like viscoelastic parameter, Hartman number, relative frequency amplitude of the oscillatory sheet to the stretching rate and Eckert number on velocity and temperature field are reported in terms of graphs and tables. The present model finds its application in polymer extrusion, drawing of plastic films and wires, glass, fiber and paper production etc.Keywords: EFGM, MHD, Oscillatory stretching sheet, Unsteady, Viscoelastic
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 189711643 Influence of Vortex Generator on Flow Behavior of Air Stream
Authors: Chakkapong Supasri, Tanongkiat Kiatsiriroat, Atipoang Nuntaphan
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This research studied the influence of delta wing and delta winglet vortex generators on air flow characteristic. Normally, the vortex generator has been used for enhancing the heat transfer performance by promote the helical flow of air stream. The vortex generator was setup in the wind tunnel and the flow pattern of air stream passing the vortex generator was observed by using smoke generator. The Reynolds number of air stream was between 30,000 and 80,000. It is found that the delta winglet having 20mm fin height and 30 degree of air stream contact angle generates the maximum helical flow of air stream.
Keywords: Vortex generator, Flow behavior, Visual study, Delta wing, Delta winglet, Smoke generator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 222411642 The New Semi-Experimental Method for Simulation of Turbine Flow Meters Rotation in the Transitional Flow
Authors: J. Tonkonogij, A. Pedišius, A. Stankevičius
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The new semi-experimental method for simulation of the turbine flow meters rotation in the transitional flow has been developed. The method is based on the experimentally established exponential low of changing of dimensionless relative turbine gas meter rotation frequency and meter inertia time constant. For experimental evaluation of the meter time constant special facility has been developed. The facility ensures instant switching of turbine meter under test from one channel to the other channel with different flow rate and measuring the meter response. The developed method can be used for evaluation and predication of the turbine meters response and dynamic error in the transitional flow with any arbitrary law of flow rate changing. The examples of the method application are presented.Keywords: Dynamic error, pulsing flow, numerical simulation, response, turbine gas meters.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 220111641 Heat Transfer Analysis of Rectangular Channel Plate Heat Sink
Authors: Zhang Lei, Liu Min, Liu Botao
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In order to improve the simulation effects of space cold black environment, this paper described a rectangular channel plate heat sink. By using fluid mechanics theory and finite element method, the internal fluid flow and heat transfer in heat sink was numerically simulated to analyze the impact of channel structural on fluid flow and heat transfer. The result showed that heat sink temperature uniformity is well, and the impact of channel structural on the heat sink temperature uniformity is not significant. The channel depth and spacing are important factors which affect the fluid flow and heat transfer in the heat sink. The two factors of heat transfer and resistance need to be considered comprehensively to determine the optimal flow structure parameters.Keywords: heat transfer, heat sink, numerical simulation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 183811640 NGN and WiMAX: Putting the Pieces Together
Authors: Mohamed K. Watfa, Khaled Abdel Naby, Chetan Govind Bhatia
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With the exponential rise in the number of multimedia applications available, the best-effort service provided by the Internet today is insufficient. Researchers have been working on new architectures like the Next Generation Network (NGN) which, by definition, will ensure Quality of Service (QoS) in an all-IP based network [1]. For this approach to become a reality, reservation of bandwidth is required per application per user. WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communication technology which has predefined levels of QoS which can be provided to the user [4]. IPv6 has been created as the successor for IPv4 and resolves issues like the availability of IP addresses and QoS. This paper provides a design to use the power of WiMAX as an NSP (Network Service Provider) for NGN using IPv6. The use of the Traffic Class (TC) field and the Flow Label (FL) field of IPv6 has been explained for making QoS requests and grants [6], [7]. Using these fields, the processing time is reduced and routing is simplified. Also, we define the functioning of the ASN gateway and the NGN gateway (NGNG) which are edge node interfaces in the NGNWiMAX design. These gateways ensure QoS management through built in functions and by certain physical resources and networking capabilities.Keywords: WiMAX, NGN, QoS, IPv6, Flow Label, ASNGateway
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 167211639 Open Channel Flow Measurement of Water by Using Width Contraction
Authors: Arun Goel, D. V. S. Verma, Sanjeev Sangwan
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Present study was aimed to develop a discharge measuring device for irrigation and laboratory channels. Experiments were conducted on sharp edged constricted flow meters having four types of width constrictions namely 2:1, 1.5:1, 1:1 and 90o in the direction of flow. These devices were made of MS sheets and installed separately in a rectangular flume. All these four devices were tested under free and submerged flow conditions. Eight different discharges varying from 2 lit/sec to 30 lit/sec were passed through each device. In total around 500 observations of upstream and downstream depths were taken in the present work. For each discharge, free submerged and critical submergence under different flow conditions were noted and plotted. Once the upstream and downstream depths of flow over any of the device are known, the discharge can be easily calculated with the help of the curves developed for free and submerged flow conditions. The device having contraction 2:1 is the most efficient one as it allows maximum critical submergence.Keywords: Flowrate, flowmeter, open channels, submergence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 231911638 Analysis of Air-Water Two-Phase Flow in a 3x3 Rod Bundle
Authors: Pei-Syuan Ruan, Ya-Chi Yu, Shao-Wen Chen, Jin-Der Lee, Jong-Rong Wang, Chunkuan Shih
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This study investigated the void fraction characteristics under low superficial gas velocity (Jg) and low superficial fluid velocity (Jf) conditions in a 3x3 rod bundle geometry. Three arrangements of conductivity probes were set to measure the void fraction at various cross-sectional regions, including rod-gap, sub-channel and rod-wall regions. The experimental tests were performed under the flow conditions of Jg = 0-0.236 m/s and Jf = 0-0.142 m/s, and the time-averaged void fractions were recorded at each flow condition. It was observed that while the superficial gas velocity increases, the small bubbles started to cluster together and become big bubbles. As the superficial fluid velocity increases, the local void fractions of the three test regions will get closer and the bubble distribution will be more uniform across the cross section.
Keywords: Conductivity probes, rod bundles, two-phase flow, void fraction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 55511637 MHD Non-Newtonian Nanofluid Flow over a Permeable Stretching Sheet with Heat Generation and Velocity Slip
Authors: Rama Bhargava, Mania Goyal
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The problem of magnetohydrodynamics boundary layer flow and heat transfer on a permeable stretching surface in a second grade nanofluid under the effect of heat generation and partial slip is studied theoretically. The Brownian motion and thermophoresis effects are also considered. The boundary layer equations governed by the PDE’s are transformed into a set of ODE’s with the help of local similarity transformations. The differential equations are solved by variational finite element method. The effects of different controlling parameters on the flow field and heat transfer characteristics are examined. The numerical results for the dimensionless velocity, temperature and nanoparticle volume fraction as well as the reduced Nusselt and Sherwood number have been presented graphically. The comparison confirmed excellent agreement. The present study is of great interest in coating and suspensions, cooling of metallic plate, oils and grease, paper production, coal water or coal-oil slurries, heat exchangers technology, materials processing exploiting.
Keywords: Viscoelastic nanofluid, partial slip, stretching sheet, heat generation/absorption, MHD flow, FEM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 327411636 Unsteady Flow and Heat Transfer of Nanofluid from Circular Tube in Cross-Flow
Authors: H. Bayat, M. Majidi, M. Bolhasani, A. Karbalaie Alilou, A. Mirabdolah Lavasani
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Unsteady flow and heat transfer from a circular cylinder in cross-flow is studied numerically. The governing equations are solved by using finite volume method. Reynolds number varies in range of 50 to 200; in this range flow is considered to be laminar and unsteady. Al2O3 nanoparticle with volume fraction in range of 5% to 20% is added to pure water. Effects of adding nanoparticle to pure water on lift and drag coefficient and Nusselt number is presented. Addition of Al2O3 has inconsiderable effect on the value of drags and lift coefficient. However, it has significant effect on heat transfer; results show that heat transfer of Al2O3 nanofluid is about 9% to 36% higher than pure water.
Keywords: Nanofluid, heat transfer, unsteady flow, forced convection, cross-flow.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 252111635 Aerodynamic Performance of a Pitching Bio-Inspired Corrugated Airfoil
Authors: Hadi Zarafshani, Shidvash Vakilipour, Shahin Teimori, Sara Barati
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In the present study, the aerodynamic performance of a rigid two-dimensional pitching bio-inspired corrugate airfoil was numerically investigated at Reynolds number of 14000. The Open Field Operations And Manipulations (OpenFOAM) computational fluid dynamic tool is used to solve flow governing equations numerically. The k-ω SST turbulence model with low Reynolds correction (k-ω SST LRC) and the pimpleDyMFOAM solver are utilized to simulate the flow field around pitching bio-airfoil. The lift and drag coefficients of the airfoil are calculated at reduced frequencies k=1.24-4.96 and the angular amplitude of A=5°-20°. Results show that in a fixed reduced frequency, the absolute value of the sectional lift and drag coefficients increase with increasing pitching amplitude. In a fixed angular amplitude, the absolute value of the lift and drag coefficients increase as the pitching reduced frequency increases.
Keywords: Bio-inspired pitching airfoils, OpenFOAM, low Reynolds k-ω SST model, lift and drag coefficients.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 90411634 Capture Zone of a Well Field in an Aquifer Bounded by Two Parallel Streams
Authors: S. Nagheli, N. Samani, D. A. Barry
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In this paper, the velocity potential and stream function of capture zone for a well field in an aquifer bounded by two parallel streams with or without a uniform regional flow of any directions are presented. The well field includes any number of extraction or injection wells or a combination of both types with any pumping rates. To delineate the capture envelope, the potential and streamlines equations are derived by conformal mapping method. This method can help us to release constrains of other methods. The equations can be applied as useful tools to design in-situ groundwater remediation systems, to evaluate the surface–subsurface water interaction and to manage the water resources.Keywords: Complex potential, conformal mapping, groundwater remediation, image well theory, Laplace’s equation, superposition principle.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 86911633 Threshold Submergence of Flow over PK Weirs
Authors: A. Javaheri, A. R. Kabiri-Samani
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In this study an extensive experimental research is carried out to develop a better understanding of the effects of Piano Key (PK) weir geometry on weir flow threshold submergence. Experiments were conducted in a 12 m long, 0.4 m wide and 0.7 m deep rectangular glass wall flume. The main objectives were to investigate the effect of the PK weir geometries including the weir length, weir height, inlet-outlet key widths, upstream and downstream apex overhangs, and slopped floors on threshold submergence and study the hydraulic flow characteristics. From the experimental results, a practical formula is proposed to evaluate the flow threshold submergence over PK weirs.Keywords: Model experimentation, flow characteristics, Piano Key weir, threshold submergence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 218011632 Investigation of Flow Characteristics on Upstream and Downstream of Orifice Using Computational Fluid Dynamics
Authors: War War Min Swe, Aung Myat Thu, Khin Cho Thet, Zaw Moe Htet, Thuzar Mon
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The main parameter of the orifice hole diameter was designed according to the range of throttle diameter ratio which gave the required discharge coefficient. The discharge coefficient is determined by difference diameter ratios. The value of discharge coefficient is 0.958 occurred at throttle diameter ratio 0.5. The throttle hole diameter is 80 mm. The flow analysis is done numerically using ANSYS 17.0, computational fluid dynamics. The flow velocity was analyzed in the upstream and downstream of the orifice meter. The downstream velocity of non-standard orifice meter is 2.5% greater than that of standard orifice meter. The differential pressure is 515.379 Pa in standard orifice.
Keywords: CFD-CFX, discharge coefficients, flow characteristics, inclined.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 57311631 Study the Effect of Roughness on the Higher Order Moment to Extract Information about the Turbulent Flow Structure in an Open Channel Flow
Authors: Md Abdullah Al Faruque, Ram Balachandar
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The present study was carried out to understand the extent of effect of roughness and Reynolds number in open channel flow (OCF). To this extent, four different types of bed surface conditions consisting smooth, distributed roughness, continuous roughness, natural sand bed and two different Reynolds number for each bed surfaces were adopted in this study. Particular attention was given on mean velocity, turbulence intensity, Reynolds shear stress, correlation, higher order moments and quadrant analysis. Further, the extent of influence of roughness and Reynolds number in the depth-wise direction also studied. Increasing Reynolds shear stress near rough beds are noticed due to arrays of discrete roughness elements and flow over these elements generating a series of wakes which contributes to the generation of significantly higher Reynolds shear stress.
Keywords: Bed roughness, ejection, sweep, open channel flow, Reynolds Shear Stress, turbulent boundary layer, velocity triple product.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 173011630 Computational Fluid Dynamics Study on Water Soot Blower Direction in Tangentially Fired Pulverized-Coal Boiler
Authors: Teewin Plangsrinont, Wasawat Nakkiew
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In this study, Computational Fluid Dynamics (CFD) was utilized to simulate and predict the path of water from water soot blower through an ambient flow field in 300-megawatt tangentially burned pulverized coal boiler that utilizes a water soot blower as a cleaning device. To predict the position of the impact of water on the opposite side of the water soot blower under identical conditions, the nozzle size and water flow rate were fixed in this investigation. The simulation findings demonstrated a high degree of accuracy in predicting the direction of water flow to the boiler's water wall tube, which was validated by comparison to experimental data. Results show maximum deviation value of the water jet trajectory is 10.2%.
Keywords: Computational fluid dynamics, tangentially fired boiler, thermal power plant, water soot blower.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 70311629 Investigation of the Aerodynamic Characters of Ducted Fan System
Authors: Wang Bo , Guo Zheng , Wang Peng , Shan Shangqiu , Hou Zhongxi
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This paper investigates the aerodynamic characters of a model ducted fan system, analyses the basic principle of the effect of thrust promotion and torque reduction, discovers the relationship between the revolutions per minute(RPM) of the fan and the characters of thrust, as well as system torque. Firstly a model ducted fan has been designed and manufactured according to the specific structure of flow field, then CFD simulation has been carried out to analyze such aerodynamics, finally bench tests have been used to validate the simulation results and system configuration.
Keywords: ducted fan, free vortex flow, stator blade, screw torque, thrust increase
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 440611628 A Comparison between Heterogeneous and Homogeneous Gas Flow Model in Slurry Bubble Column Reactor for Direct Synthesis of DME
Authors: Sadegh Papari, Mohammad Kazemeini, Moslem Fattahi
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In the present study, a heterogeneous and homogeneous gas flow dispersion model for simulation and optimisation of a large-scale catalytic slurry reactor for the direct synthesis of dimethyl ether (DME) from syngas and CO2, using a churn-turbulent regime was developed. In the heterogeneous gas flow model the gas phase was distributed into two bubble phases: small and large, however in the homogeneous one, the gas phase was distributed into only one large bubble phase. The results indicated that the heterogeneous gas flow model was in more agreement with experimental pilot plant data than the homogeneous one.Keywords: Modelling, Slurry bubble column, Dimethyl ether synthesis, Homogeneous gas flow, Heterogeneous gas flow
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 216611627 Case on Manufacturing Cell Formation Using Production Flow Analysis
Authors: Vladimír Modrák
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This paper offers a case study, in which methodological aspects of cell design for transformation the production process are applied. The cell redesign in this work is tightly focused to reach optimization of material flows under real manufacturing conditions. Accordingly, more individual techniques were aggregated into compact methodical procedure with aim to built one-piece flow production. Case study was concentrated on relatively typical situation of transformation from batch production to cellular manufacturing.Keywords: Product/Quantity analysis, layout, design, manufacturing process.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 334011626 Signal and Harmonic Analysis of a Compressor Blade for Identification of the Nonlinear Frequency Vibration
Authors: Farhad Asadi, Gholamhasan Payganeh
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High-speed turbomachine can experience significant centrifugal and gas bending loads. As a result, the compressor blades must be able to resist high-frequency oscillations due to surge or stall condition in flow field dynamics. In this paper, vibration characteristics of the 6th stage blade compressor have been examined in detail with, using 3-D finite element (FE) methods. The primary aim of this article is to gain an understanding of nonlinear vibration induced in the blade against different loading conditions. The results indicate the nonlinear behavior of the blade as a result of the amplitude of resonances or material properties. Since one of the leading causes of turbine blade failure is high cycle fatigue, simulations were started by specifying the stress distribution in the blade due to the centrifugal rotation. Next, resonant frequencies and critical speeds of the blade were defined by modal analysis. Finally, the harmonic analysis was simulated on the blades.
Keywords: Nonlinear vibration, modal analysis, resonance, frequency response, compressor blade.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 61211625 Scheduling a Flexible Flow Shops Problem using DEA
Authors: Fatemeh Dadkhah, Hossein Ali Akbarpour
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This paper considers a scheduling problem in flexible flow shops environment with the aim of minimizing two important criteria including makespan and cumulative tardiness of jobs. Since the proposed problem is known as an Np-hard problem in literature, we have to develop a meta-heuristic to solve it. We considered general structure of Genetic Algorithm (GA) and developed a new version of that based on Data Envelopment Analysis (DEA). Two objective functions assumed as two different inputs for each Decision Making Unit (DMU). In this paper we focused on efficiency score of DMUs and efficient frontier concept in DEA technique. After introducing the method we defined two different scenarios with considering two types of mutation operator. Also we provided an experimental design with some computational results to show the performance of algorithm. The results show that the algorithm implements in a reasonable time.Keywords: Data envelopment analysis, Efficiency, Flexible flow shops, Genetic algorithm
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 181311624 Slugging Frequency Correlation for Inclined Gas-liquid Flow
Authors: V. Hernandez-Perez, M. Abdulkadir, B. J. Azzopardi
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In this work, new experimental data for slugging frequency in inclined gas-liquid flow are reported, and a new correlation is proposed. Scale experiments were carried out using a mixture of air and water in a 6 m long pipe. Two different pipe diameters were used, namely, 38 and 67 mm. The data were taken with capacitance type sensors at a data acquisition frequency of 200 Hz over an interval of 60 seconds. For the range of flow conditions studied, the liquid superficial velocity is observed to influence the frequency strongly. A comparison of the present data with correlations available in the literature reveals a lack of agreement. A new correlation for slug frequency has been proposed for the inclined flow, which represents the main contribution of this work.Keywords: slug frequency, inclined flow
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 316111623 Experimental Study of Light Crude Oil-Water Emulsions
Authors: M. Meriem-Benziane, Sabah A. Abdul-Wahab, H. Zahloul, M. Belhadri
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This paper made an attempt to investigate the problem associated with enhancement of emulsions of light crude oil-water recovery in an oil field of Algerian Sahara. Measurements were taken through experiments using RheoStress (RS600). Factors such as shear rate, temperature and light oil concentration on the viscosity behavior were considered. Experimental measurements were performed in terms of shear stress–shear rate, yield stress and flow index on mixture of light crude oil–water. The rheological behavior of emulsion showed Non-Newtonian shear thinning behavior (Herschel-Bulkley). The experiments done in the laboratory showed the stability of some water in light crude oil emulsions form during consolidate oil recovery process. To break the emulsion using additives may involve higher cost and could be very expensive. Therefore, further research should be directed to find solution of these problems that have been encountered.
Keywords: Emulsion, Flow index, Herschel-Bulkley model, Newton model, Oil field, Rheology, Yield stress
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 152211622 Oil-Water Two-Phase Flow Characteristics in Horizontal Pipeline – A Comprehensive CFD Study
Authors: Anand B. Desamala, Ashok Kumar Dasamahapatra, Tapas K. Mandal
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In the present work, detailed analysis on flow characteristics of a pair of immiscible liquids through horizontal pipeline is simulated by using ANSYS FLUENT 6.2. Moderately viscous oil and water (viscosity ratio = 107, density ratio = 0.89 and interfacial tension = 0.024 N/m) have been taken as system fluids for the study. Volume of Fluid (VOF) method has been employed by assuming unsteady flow, immiscible liquid pair, constant liquid properties, and co-axial flow. Meshing has been done using GAMBIT. Quadrilateral mesh type has been chosen to account for the surface tension effect more accurately. From the grid independent study, we have selected 47037 number of mesh elements for the entire geometry. Simulation successfully predicts slug, stratified wavy, stratified mixed and annular flow, except dispersion of oil in water, and dispersion of water in oil. Simulation results are validated with horizontal literature data and good conformity is observed. Subsequently, we have simulated the hydrodynamics (viz., velocity profile, area average pressure across a cross section and volume fraction profile along the radius) of stratified wavy and annular flow at different phase velocities. The simulation results show that in the annular flow, total pressure of the mixture decreases with increase in oil velocity due to the fact that pipe cross section is completely wetted with water. Simulated oil volume fraction shows maximum at the centre in core annular flow, whereas, in stratified flow, maximum value appears at upper side of the pipeline. These results are in accord with the actual flow configuration. Our findings could be useful in designing pipeline for transportation of crude oil.
Keywords: CFD, Horizontal pipeline, Oil-water flow, VOF technique.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 570911621 Traffic Flow Prediction using Adaboost Algorithm with Random Forests as a Weak Learner
Authors: Guy Leshem, Ya'acov Ritov
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Traffic Management and Information Systems, which rely on a system of sensors, aim to describe in real-time traffic in urban areas using a set of parameters and estimating them. Though the state of the art focuses on data analysis, little is done in the sense of prediction. In this paper, we describe a machine learning system for traffic flow management and control for a prediction of traffic flow problem. This new algorithm is obtained by combining Random Forests algorithm into Adaboost algorithm as a weak learner. We show that our algorithm performs relatively well on real data, and enables, according to the Traffic Flow Evaluation model, to estimate and predict whether there is congestion or not at a given time on road intersections.Keywords: Machine Learning, Boosting, Classification, TrafficCongestion, Data Collecting, Magnetic Loop Detectors, SignalizedIntersections, Traffic Signal Timing Optimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 390811620 Hemodynamic Characteristics in the Human Carotid Artery Model Induced by Blood-Arterial Wall Interactions
Authors: Taewon Seo
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The characteristics of physiological blood flow in human carotid arterial bifurcation model have been numerically studied using a fully coupled fluid-structure interaction (FSI) analysis. This computational model with the fluid-structure interaction is constructed to investigate the flow characteristics and wall shear stress in the carotid artery. As the flow begins to decelerate after the peak flow, a large recirculation zone develops at the non-divider wall of both internal carotid artery (ICA) and external carotid artery (ECA) in FSI model due to the elastic energy stored in the expanding compliant wall. The calculated difference in wall shear stress (WSS) in both Non-FSI and FSI models is a range of between 5 and 11% at the mean WSS. The low WSS corresponds to regions of carotid artery that are more susceptible to atherosclerosis.
Keywords: Carotid artery, Fluid-structure interaction, Hemodynamics, Wall shear stress.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 286611619 Numerical Simulation and Experimental Validation of the Hydraulic L-Shaped Check Ball Behavior
Authors: Shinji Kajiwara
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The spring-driven ball-type check valve is one of the most important components of hydraulic systems: it controls the position of the ball and prevents backward flow. To simplify the structure, the spring must be eliminated, and to accomplish this, the flow pattern and the behavior of the check ball in L-shaped pipe must be determined. In this paper, we present a full-scale model of a check ball made of acrylic resin, and we determine the relationship between the initial position of the ball, the position and diameter of the inflow port. The check flow rate increases in a standard center inflow model, and it is possible to greatly decrease the check-flow rate by shifting the inflow from the center.
Keywords: Hydraulics, Pipe Flow, Numerical Simulation, Flow Visualization, Check ball, L-shaped Pipe.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 207711618 Numerical Study of Liquefied Petroleum Gas Laminar Flow in Cylindrical Elliptic Pipes
Authors: Olumuyiwa A. Lasode, Tajudeen O. Popoola, B. V. S. S. S. Prasad
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Fluid flow in cylinders of elliptic cross-section was investigated. Fluid used is Liquefied petroleum gas (LPG). LPG found in Nigeria contains majorly butane with percentages of propane. Commercial available code FLUENT which uses finite volume method was used to solve fluid flow governing equations. There has been little attention paid to fluid flow in cylindrical elliptic pipes. The present work aims to predict the LPG gas flow in cylindrical pipes of elliptic cross-section. Results of flow parameters of velocity and pressure distributions are presented. Results show that the pressure drop in elliptic pipes is higher than circular pipe of the same cross-sectional area. This is an important result as the pressure drop is related to the pump power needed to drive the flow. Results show that the velocity increases towards centre of the pipe as the flow moves downstream, and also increases towards the outlet of the pipe.
Keywords: Elliptic Pipes, Liquefied Petroleum Gas, Numerical Study, Pressure Drop.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 290811617 Development of Logic Model for R&D Program Plan Analysis in Preliminary Feasibility Study
Authors: Hyun-Kyu Kang
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The Korean Government has applied the preliminary feasibility study to new government R&D program plans as a part of an evaluation system for R&D programs. The preliminary feasibility study for the R&D program is composed of 3 major criteria such as technological, policy and economic analysis. The program logic model approach is used as a part of the technological analysis in the preliminary feasibility study. We has developed and improved the R&D program logic model. The logic model is a very useful tool for evaluating R&D program plans. Using a logic model, we can generally identify important factors of the R&D program plan, analyze its logic flow and find the disconnection or jump in the logic flow among components of the logic model.
Keywords: Preliminary feasibility study, R&D program logic model, technological analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 215511616 Throughflow Effects on Thermal Convection in Variable Viscosity Ferromagnetic Liquids
Authors: G. N. Sekhar, P. G. Siddheshwar, G. Jayalatha, R. Prakash
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The problem of thermal convection in temperature and magnetic field sensitive Newtonian ferromagnetic liquid is studied in the presence of uniform vertical magnetic field and throughflow. Using a combination of Galerkin and shooting techniques the critical eigenvalues are obtained for stationary mode. The effect of Prandtl number (Pr > 1) on onset is insignificant and nonlinearity of non-buoyancy magnetic parameter M3 is found to have no influence on the onset of ferroconvection. The magnetic buoyancy number, M1 and variable viscosity parameter, V have destabilizing influences on the system. The effect of throughflow Peclet number, Pe is to delay the onset of ferroconvection and this effect is independent of the direction of flow.Keywords: Ferroconvection, throughflow, temperature dependent viscosity, magnetic field dependent viscosity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 114511615 CFD Effect of the Tidal Grating in Opposite Directions
Authors: N. M. Thao, I. Dolguntseva, M. Leijon
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Flow blockages referring to the increase in flow are being considered as a vital equipment for marine current energy conversion. However, the shape of these devices will result in extracted energy under the operation. The present work investigates the effect of two configurations of a grating, convergent and divergent that located upstream, to the water flow velocity. The flow characteristics are studied by Computational Fluid Dynamic simulation by using the ANSYS Fluent solver for these specified arrangements of the grating. The results indicate that distinguished characteristics of flow velocity between “convergent” and “divergent” grating placements is up to 10% in confined conditions. Furthermore, the velocity in case of convergent grating is higher than that of divergent grating.
Keywords: Marine current energy, marine current energy converter, turbine grating, RANS simulation, water flow velocity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1719