Transportation Performance of Highly Concentrated Coal-Water Slurries Prepared from Indian Coals

2014 ◽  
Vol 592-594 ◽  
pp. 869-873 ◽  
Author(s):  
Arunanshu Chakravarthy ◽  
Satish Kumar ◽  
S.K. Mohapatra
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Rheological Behaviour ◽  
Pseudoplastic Fluid ◽  
Ansys Fluent ◽  
Water Slurry ◽  
Solids Concentration ◽  
Coal Water Slurry ◽  
Indian Coals ◽  
Fluid Behaviour

The rheological behaviour of concentrated coal-water slurries prepared from three different Indian coals were investigated using an Anton Paar rheometer. The perspective was laid in to study the effect of solids concentration on the rheological behaviour of coal water slurry. It was observed that coal water slurry exhibited non-Newtonian pseudoplastic fluid behaviour at concentrations above 30 % by weight. The apparent viscosity varied with the amount of coal in the slurry. The rheological data were utilized to predict the pressure drop characteristics of coal water slurry flowing through a 53 mm diameter slurry pipeline using ANSYS Fluent 14.0 computational fluid dynamics code.

Synthesis and Properties of Hyperbranched Dispersant for High Concentration of CWS

2013 ◽  
Vol 805-806 ◽  
pp. 1439-1442
Author(s):  
Jin Xu Dai ◽  
Guang Hua Zhang ◽  
Wen Jing Han
Keyword(s):  
Addition Reaction ◽  
Condensation Reaction ◽  
Rheological Behaviour ◽  
Static Stability ◽  
Michael Addition Reaction ◽  
High Concentration ◽  
Pseudoplastic Fluid ◽  
1.5 Generation ◽  
Water Slurry ◽  
Coal Water Slurry

The 1.5 generation hyperbranched molecule was synthesized with dehydroabietylamine as the core by means of Michael addition reaction and amidation condensation reaction with ethylenediamine and methyl acrylate as raws by divergent method. Then, the dispersant was synthesized by means of the 1.5G hyperbranched molecule as initiator by reaction with 2-aminoethanesulfonic acid. The structure of products were identified by IR spectra and 1HNMR spectra. The influences of dispersant on apparent viscosity,rheological behaviour and static stability of coal water slurry prepared from Shenfu coal are studied. The results showed that as the slurry concentration reach at 67% the dosage of the dispersant was 0.4% (m/m), the viscosity of the coal water slurry was only at 987 mPa·s. The rheological investigation indicates that the slurry pumped with dispersant is pseudoplastic fluid.

Experimental and simulation study of thermal accumulation in an enclosed vehicle

2019 ◽  
Vol 233 (14) ◽  
pp. 3621-3629
Author(s):  
Sing Ngie David Chua ◽  
Boon Kean Chan ◽  
Soh Fong Lim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
Heat Accumulation ◽  
Ansys Fluent ◽  
Direct Exposure ◽  
Car Park

Thermal accumulation in a car cabin under direct exposure to sunlight can be extremely critical due to the risk of heatstroke especially to children who are left unattended in the car. There are very limited studies in the literature to understand the thermal behaviour of a car that is parked in an open car park space and the findings are mostly inconsistent among researchers. In this paper, the studies of thermal accumulation in an enclosed vehicle by experimental and computational fluid dynamics simulation approaches were carried out. An effective and economical method to reduce the heat accumulation was proposed. Different test conditions such as fully enclosed, fully enclosed with sunshade on front windshield and different combinations of window gap sizes were experimented and presented. Eight points of measurement were recorded at different locations in the car cabin and the results were used as the boundary conditions for the three-dimensional computational fluid dynamics simulation. The computational fluid dynamics software used was ANSYS FLUENT 16.0. The results showed that the application of sunshade helped to reduce thermal accumulation at car cabin by 11.5%. The optimum combination of windows gap size was found to be with 4-cm gap on all four windows which contributed to a 21.1% reduction in car cabin temperature. The results obtained from the simulations were comparable and in agreement with the experimental tests.

Computational Fluid Dynamics Modelling of a Load Sensing Proportional Valve

2019 ◽  
Author(s):  
Alessandro Corvaglia ◽  
Giorgio Altare ◽  
Roberto Finesso ◽  
Massimo Rundo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Complex Geometry ◽  
Ansys Fluent ◽  
Proportional Valve ◽  
Fluid Forces ◽  
Load Sensing ◽  
Cfd Models ◽  
Dynamics Modelling

Abstract In this paper, two 3D CFD models of a load sensing proportional valve are contrasted. The models were developed with two different software, Simerics PumpLinx® and ANSYS Fluent®. In both cases the mesh was dynamically modified based on the fluid forces acting on the local compensator. In the former, a specific template for valves was used, in the latter a user-defined function was implemented. The models were validated in terms of flow rate and pressure drop for different positions of the main spool by means of specific tests. Two configurations were tested: with the local compensator blocked and free to regulate. The study has brought to evidence the reliability of the CFD models in evaluating the steady-state characteristics of valves with complex geometry.

High Swept-Back Delta Wing Flow

2014 ◽  
Vol 1016 ◽  
pp. 377-382 ◽  
Author(s):  
Thi Kim Dung Hoang ◽  
Phu Khanh Nguyen ◽  
Yoshiaki Nakamura
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Lift Force ◽  
Delta Wing ◽  
Air Velocity ◽  
Rolling Angle ◽  
Ansys Fluent ◽  
Absolute Value ◽  
Numerical Tests ◽  
Low Speed Wind Tunnel

In this study, an experimentally and numerically investigation was carried out to obtain characteristics (lift force, drag force ...) on 74.5 degree Delta wing. The experiment tests were conducted at Hanoi University of Science and Technology low-speed wind tunnel facility, whereas the numerical tests were performed using the commercial computational fluid dynamics software ANSYS/FLUENT. The apparition of the vortices upon the Delta wing caused the negative pressure distribution on the wing which reached a maximum absolute value at the vortex core. The characteristics of high swept-back Delta wing were investigated at air velocity of 10 m/s and attack angle of 20 degree in changing the rolling angle of the wing from 0 to 20 degree.

Computational fluid dynamics analysis of a modified Savonius rotor and optimization using response surface methodology

2017 ◽  
Vol 41 (5) ◽  
pp. 285-296 ◽  
Author(s):  
Haris Moazam Sheikh ◽  
Zeeshan Shabbir ◽  
Hassan Ahmed ◽  
Muhammad Hamza Waseem ◽  
Muhammad Zubair Sheikh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Design Of Experiment ◽  
Coefficient Of Performance ◽  
Speed Ratio ◽  
Ansys Fluent ◽  
Computational Fluid Dynamics Analysis ◽  
Parametric Effects

This article aims to present a two-dimensional parametric analysis of a modified Savonius wind turbine using computational fluid dynamics. The effects of three independent parameters of the rotor, namely, shape factor, overlap ratio, and tip speed ratio on turbine performance were studied and then optimized for maximum coefficient of performance using response surface methodology. The rotor performance was analyzed over specific domains of the parameters under study, and three-variable Box-Behnken design was used for design of experiment. The specific parametric combinations as per design of experiment were simulated using ANSYS Fluent®, and the response variable, coefficient of performance (Cp), was calculated. The sliding mesh model was utilized, and the flow was simulated using Shear Stress Transport (SST) k − ω model. The model was validated using past experimental results and found to predict parametric effects accurately. Minitab® and ReliaSoft DOE++® were used to develop regression equation and find the optimum combination of parameters for coefficient of performance over the specified parametric domains using response surface methodology.

Analysis and Simulation of Inner Flow Condition of a Novel Rotary on/off Valve

2012 ◽  
Vol 220-223 ◽  
pp. 1698-1702
Author(s):  
Jian Chen ◽  
Zhu Ming Su ◽  
Qi Zhou ◽  
Jian Ping Shu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Condition ◽  
High Speed ◽  
Ansys Fluent ◽  
Revolution Speed ◽  
Pressure Profiles ◽  
Open Case ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

A novel hydraulic rotary high speed on/off valve is investigated. The function of the outlet turbine and the effect on revolution speed of valve spool are analyzed. The inner fluid flow condition under full open case of the on/off valve is simulated using computational fluid dynamics(CFD) method based on Ansys/Fluent and velocity and pressure profiles of fluid inside valve are obtained. Suggestions on optimizing the geometry of valve to decrease transition losses are given.

Surface Engineering of Low Rank Indian Coals by Starch-Based Additives for the Formulation of Concentrated Coal−Water Slurry

2010 ◽  
Vol 24 (2) ◽  
pp. 1260-1268 ◽  
Author(s):  
Debadutta Das ◽  
Uma Dash ◽  
Amalendu Nayak ◽  
Pramila K. Misra
Keyword(s):  
Surface Engineering ◽  
Low Rank ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Indian Coals

scholarly journals Modelling a Biochemical Reaction with Computational Fluid Dynamics

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Sotos C. Generalis ◽  
Gregory M Cartland Glover
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Bubble Column ◽  
Reaction Model ◽  
Biochemical Reaction ◽  
Single Plane ◽  
Solids Concentration ◽  
Computational Fluid Dynamics Cfd ◽  
Specific Growth Rates ◽  
The Impact

Earlier investigations (Cartland Glover et al., 2004) into the use of computational fluid dynamics (CFD) for the modelling of gas-liquid and gas-liquid-solid flow allowed a simple biochemical reaction model to be implemented. A single plane mesh was used to represent the transport and reaction of molasses, the mould Aspergillus niger and citric acid in a bubble column with a height to diameter aspect ratio of 20:1. Two specific growth rates were used to examine the impact that biomass growth had on the local solids concentration and the effect this had on the local hydrodynamics of the bubble column.

scholarly journals Fluid flow in the impulse valve of a hydraulic ram

2020 ◽  
Vol 3 (22) ◽  
Author(s):  
Wojciech Sobieski ◽  
Dariusz Grygo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Hydrodynamic Pressure ◽  
Water Velocity ◽  
Experimental Measurements ◽  
Ansys Fluent ◽  
Working Cycle ◽  
Numerical Studies ◽  
Minimum Force

The paper presents the results of a study investigating the equilibrium of forces acting on the closing element of the impulse valve in a water ram at the end of the acceleration stage. Acceleration is one of the three main stages in the working cycle of a water ram. In the first part of the paper, we estimated water velocity based on our earlier experimental measurements. We also calculated the minimum force required for closing the impulse valve. The second part of the paper discusses two variants of a numerical model, which was developed in ANSYS Fluent to determine the result-ant hydrodynamic pressure and, consequently, the forces acting on the head of the impulse valve at the end of the acceleration stage. The main aim of this research was to verify the applicability of numerical modeling in water ram studies. The present study was motivated by the fact that Computational Fluid Dynamics is very rarely applied to water rams. In particular, we have not found any numerical studies related to the equilibrium of forces acting on the closing element of the impulse valve in a water ram.

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