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Full-Text Articles in Engineering

Dynamic Rating Of Overhead Transmission Lines Over Complex Terrain Using A Large-Eddy Simulation Paradigm, Tyler Phillips, Ray Deleon, Inanc Senocak Jun 2017

Dynamic Rating Of Overhead Transmission Lines Over Complex Terrain Using A Large-Eddy Simulation Paradigm, Tyler Phillips, Ray Deleon, Inanc Senocak

Inanc Senocak

Dynamic Line Rating (DLR) enables rating of power line conductors using real-time weather conditions. Conductors are typically operated based on a conservative static rating that assumes worst case weather conditions to avoid line sagging to unsafe levels. Static ratings can cause unnecessary congestion on transmission lines. To address this potential issue, a simulation-based dynamic line rating approach is applied to an area with moderately complex terrain. A micro-scale wind solver — accelerated on multiple graphics processing units (GPUs) — is deployed to compute wind speed and direction in the vicinity of powerlines. The wind solver adopts the large-eddy simulation technique …


Experimental And Numerical Investigation Of Heat Transfer In Cnt Nanofluids May 2015

Experimental And Numerical Investigation Of Heat Transfer In Cnt Nanofluids

Faculty of Engineering University of Malaya

Nanofluids with their enhanced thermal conductivity are believed to be a promising coolant in heat transfer applications. In this study, carbon nanotube (CNT) nanofluids of 0.01wt%, stabilised by 1.0wt% gum arabic were used as a cooling liquid in a concentric tube laminar flow heat exchanger. The flow rate of cold fluid varied from 10 to 50g/s. Both experimental and numerical simulations were carried out to determine the heat transfer enhancement using CNT nanofluids. Computational fluid dynamics (CFD) simulations were carried out using Fluent v 6.3 by assuming single-phase approximation. Thermal conductivity, density and rheology of the nanofluid were also measured …


Aerodynamics Inside A Rapid Compression Machine, Gaurav Mittal, Chih-Jen Sung Apr 2015

Aerodynamics Inside A Rapid Compression Machine, Gaurav Mittal, Chih-Jen Sung

Dr. Gaurav Mittal

The aerodynamics inside a rapid compression machine after the end of compression is investigated using planar laser-induced fluorescence (PLIF) of acetone. To study the effect of reaction chamber configuration on the resulting aerodynamics and temperature field, experiments are conducted and compared using a creviced piston and a flat piston under varying conditions. Results show that the flat piston design leads to significant mixing of the cold vortex with the hot core region, which causes alternate hot and cold regions inside the combustion chamber. At higher pressures, the effect of the vortex is reduced. The creviced piston head configuration is demonstrated …


Vortex Formation In A Rapid Compression Machine: Influence Of Physical And Operating Parameters, Gaurav Mittal, Mandhapati Raju, Chih-Jen Sung Apr 2015

Vortex Formation In A Rapid Compression Machine: Influence Of Physical And Operating Parameters, Gaurav Mittal, Mandhapati Raju, Chih-Jen Sung

Dr. Gaurav Mittal

The performance of a rapid compression machine (RCM) with a creviced piston is assessed over a range of operating conditions through computational fluid dynamics simulations with systematic demonstration of the effects of compressed gas pressure, temperature, stroke length, and clearance on altering vortex formation and temperature homogeneity inside the reaction chamber. Simulated results show that as compressed gas pressure is reduced, the temperature homogeneity deteriorates due to the combined effect of thicker boundary layer and increased flow velocities. A further optimization of the creviced piston geometry is then required to completely suppress the roll-up vortex. Stroke length and clearance volume …


The Numerical Analysis Of Flow Field On Warship Deck, Innovative Research Publications Irp India, Kwan Ouyang, Reui-Kuo Lin, Sheng-Ju Wu, Wen-Hann Sheu Feb 2015

The Numerical Analysis Of Flow Field On Warship Deck, Innovative Research Publications Irp India, Kwan Ouyang, Reui-Kuo Lin, Sheng-Ju Wu, Wen-Hann Sheu

Innovative Research Publications IRP India

This study aims to simulate the exhaust flow field of ship by the method of computational fluid dynamics (CFD) concerning with the interference by exhaust temperature, shape of stack and rolling angles etc.. In this research wind tunnel test for a corvette has been performed to attain associated experimental data, which were used as a reference basis. During simulation process several configurations of stacks have been selected, and combining with various rolling angles, exhaust temperatures and velocities, we have generated numerous cases from which the diffusion paths and temperature distribution of the exhaust flow field can be clearly observed and …


Effect Of Spatial Inlet Velocity Profiles On The Vortex Formation Pattern In A Dilated Left Ventricle Jan 2015

Effect Of Spatial Inlet Velocity Profiles On The Vortex Formation Pattern In A Dilated Left Ventricle

Faculty of Engineering University of Malaya

Despite the advancement of cardiac imaging technologies, these have traditionally been limited to global geometrical measurements. Computational fluid dynamics (CFD) has emerged as a reliable tool that provides flow ?eld information and other variables essential for the assessment of the cardiac function. Extensive studies have shown that vortex formation and propagation during the filling phase acts as a promising indicator for the diagnosis of the cardiac health condition. Proper setting of the boundary conditions is crucial in a CFD study as they are important determinants, that affect the simulation results. In this article, the effect of different transmitral velocity profiles …


Investigation Of Convection And Diffusion During Biodiesel Production In Packed Membrane Reactor Using 3d Simulation, Abdul Aziz Abdul Raman Jul 2014

Investigation Of Convection And Diffusion During Biodiesel Production In Packed Membrane Reactor Using 3d Simulation, Abdul Aziz Abdul Raman

Abdul Aziz Abdul Raman

The 3D simulation of convection and diffusion phenomena within a ceramic membrane during transesterification reaction was the aim of this study. The ceramic membrane was a tubular micro porous TiO2/Al2O3 packed with the heterogeneous catalyst. The Navier-Stokes, Brinkman and Stephan-Maxwell equations were applied for investigation of fluid flow reaction and mass transfer within the system. The value of the convection was generally between 104 and 107 times higher than diffusion. It depends on concentration component, the diffusion coefficient and components velocity. A good agreement was found with the maximum deviation of 8% from experimental data. © 2013 The Korean Society …


Computational Fluid Dynamics In Congenital Heart Disease, William M. Decampli, I. Ricardo Argueta-Morales, Eduardo Divo, Alain J. Kassab May 2014

Computational Fluid Dynamics In Congenital Heart Disease, William M. Decampli, I. Ricardo Argueta-Morales, Eduardo Divo, Alain J. Kassab

Eduardo Divo

Computational fluid dynamics has been applied to the design, refinement, and assessment of surgical procedures and medical devices. This tool calculates flow patterns and pressure changes within a virtual model of the cardiovascular system. In the field of paediatric cardiac surgery, computational fluid dynamics is being used to elucidate the optimal approach to staged reconstruction of specific defects and study the haemodynamics of the resulting anatomical configurations after reconstructive or palliative surgery. In this paper, we review the techniques and principal findings of computational fluid dynamics studies as applied to a few representative forms of congenital heart disease.


Hydrodynamic Characteristics Of A Novel Circulating Fluidized Bed Steam Reformer Operating In The Fast Fluidization Regime, Moataz Bellah M. Mousa, Seif-Eddeen K. Fateen, Essam A. Ibrahim Jan 2011

Hydrodynamic Characteristics Of A Novel Circulating Fluidized Bed Steam Reformer Operating In The Fast Fluidization Regime, Moataz Bellah M. Mousa, Seif-Eddeen K. Fateen, Essam A. Ibrahim

Seif-Eddeen K Fateen

Circulating Fluidized Bed Steam Reformers (CFBSRs) represent an important alternative for the production of syngas for the Fisher-Tropsch (FT) process and for hydrogen production. Most research regarding this novel CFBSRs did not consider its hydrodynamic characteristics. In this work, the riser Computational Fluid Dynamics (CFD) simulations were investigated using two phase Eulerian-Eulerian approach coupled with kinetic theory of granular flow with k-epsilon model to describe the turbulence of each phase. The model equations were solved via the commercial CFD package FLUENT, which uses the finite volume numerical approach. Cold flow simulations were carried out under the fast fluidization regime and …


Modeling Of Dispersed Phase By Lagrangian Approach In Fluent - 2d Exercise, Kari Myöhänen Jan 2008

Modeling Of Dispersed Phase By Lagrangian Approach In Fluent - 2d Exercise, Kari Myöhänen

Kari Myöhänen

This shows an example calculation applying DPM model in Fluent. This is related to the other DPM presentation and was prepared for the course 'Theory and simulation of dispersed-phase multiphase flows" by Dr. Payman Jalali, Lappeenranta University of Technology.


Modeling Of Dispersed Phase By Lagrangian Approach In Fluent, Kari Myöhänen Jan 2008

Modeling Of Dispersed Phase By Lagrangian Approach In Fluent, Kari Myöhänen

Kari Myöhänen

This is a seminar work prepared for a course 'Theory and simulation of dispersed-phase multiphase flows' by Dr. Payman Jalali, Lappeenranta University of Technology


Inverse Design Of And Experimental Measurements In A Double-Passage Transonic Turbine Cascade Model, G. M. Laskowski, A. Vicharelli, G. Medic, C. J. Elkins, J. K. Eaton, Paul A. Durbin Jul 2005

Inverse Design Of And Experimental Measurements In A Double-Passage Transonic Turbine Cascade Model, G. M. Laskowski, A. Vicharelli, G. Medic, C. J. Elkins, J. K. Eaton, Paul A. Durbin

Paul A. Durbin

A new transonic turbine cascade model that accurately produces infinite cascade flow conditions with minimal compressor requirements is presented. An inverse design procedure using the Favre-averaged Navier-Stokes equations and k-ε turbulence model based on the method of steepest descent was applied to a geometry consisting of a single turbine blade in a passage. For a fixed blade geometry, the passage walls were designed such that the surface isentropic Mach number (SIMN) distribution on the blade in the passage matched the SIMN distribution on the blade in an infinite cascade, while maintaining attached flow along both passage walls. An experimental rig …