Numerical Study for the Influence of Environment Temperature on Offshore Arctic Pipeline and Impingement Erosion Analysis by using Thermal Flow Simulation

2015 ◽  
Vol 39 (3) ◽  
pp. 201-205
Author(s):  
Chul Hee Jo ◽  
Jun-Ho Lee ◽  
Choon-Man Jang ◽  
Su-Jin Heang
Keyword(s):  
Numerical Study ◽  
Flow Simulation ◽  
Thermal Flow ◽  
Environment Temperature

A NUMERICAL STUDY ON THE HEMODYNAMIC AND SHEAR STRESS OF DOUBLE ANEURYSM THROUGH S-SHAPED VESSEL

2015 ◽  
Vol 27 (04) ◽  
pp. 1550033 ◽  
Author(s):  
Mahdi Halabian ◽  
Alireza Karimi ◽  
Borhan Beigzadeh ◽  
Mahdi Navidbakhsh
Keyword(s):  
Blood Flow ◽  
Mechanical Behavior ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
The Body ◽  
Sweep Angle ◽  
Abdominal Aortic ◽  
Hemodynamic Characteristics ◽  
Refined Meshes

Abdominal aortic aneurysm (AAA) is a degenerative disease defined as the abnormal ballooning of the abdominal aorta (AA) wall which is usually caused by atherosclerosis. The aneurysm grows larger and eventually ruptures if it is not diagnosed and treated. Aneurysms occur mostly in the aorta, the main artery of the chest and abdomen. The aorta carries blood flow from the heart to all parts of the body, including the vital organs, the legs, and feet. The objective of the present study is to investigate the combined effects of aneurysm and curvature on flow characteristics in S-shaped bends with sweep angle of 90° at Reynolds number of 900. The fluid mechanics of blood flow in a curved artery with abnormal aortic is studied through a mathematical analysis and employing Cosmos flow simulation. Blood is modeled as an incompressible non-Newtonian fluid and the flow is assumed to be steady and laminar. Hemodynamic characteristics are analyzed. Grid independence is tested on three successively refined meshes. It is observed that the abrupt expansion induced by AAA results in an immensely disturbed regime. The results may have implications not only for understanding the mechanical behavior of the blood flow inside an aneurysm artery but also for investigating the mechanical behavior of the blood flow in different arterial diseases, such as atherosclerosis.

Numerical Study of the Effect of Magnetic Fields on Melt-Crystal Interface-Deflection in Czochralski Crystal Growth

2003 ◽  
Author(s):  
Lijun Liu ◽  
Koichi Kakimoto
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Numerical Study ◽  
Silicon Crystal ◽  
Czochralski Growth ◽  
Thermal Flow ◽  
Interface Shape ◽  
Convective Thermal ◽  
And Control ◽  
Crystal Interface

In order to control the impurity distribution and remove defects in a crystal grown in Czochralski growth for high quality crystals of silicon, it is necessary to study and control the melt-crystal interface shape, which plays an important role in control of the crystal quality. The melt-crystal interface interacts with and is determined by the convective thermal flow of the melt in the crucible. Application of magnetic field in the Czochralski system is an effective tool to control the convective thermal flow in the crucible. Therefore, the shape of the melt-crystal interface can be modified accordingly. Numerical study is performed in this paper to understand the effect of magnetic field on the interface deflection in Czochralski system. Comparisons have been carried out by computations for four arrangements of the magnetic field: without magnetic field, a vertical magnetic field and two types of cusp-shaped magnetic field. The velocity, pressure, thermal and electromagnetic fields are solved with adaptation of the mesh to the iteratively modified interface shape. The multi-block technique is applied to discretize the melt field in the crucible and the solid field of silicon crystal. The unknown shape of the melt-crystal interface is achieved by an iterative procedure. The computation results show that the magnetic fields have obvious effects on both the pattern and strength of the convective flow and the interface shape. Applying magnetic field in the Czochralski system, therefore, is an effective tool to control the quality of bulk crystal in Czochralski growth process.

Effect of Hole Pitch Ratio and Compound Angle on the Thermal Flow Fields of Double-Jet Film Cooling Hole

2014 ◽  
Author(s):  
Moon-Young Cho ◽  
Hyeon-Seok Seo ◽  
Youn-Jea Kim
Keyword(s):  
Film Cooling ◽  
Numerical Study ◽  
Turbine Blades ◽  
Flow Characteristics ◽  
Thermal Flow ◽  
Film Cooling Effectiveness ◽  
Gas Turbine Blades ◽  
Ansys Cfx ◽  
Cooling Hole ◽  
Pitch Distance

In this study, the effect of a row of double-jet film-cooling hole configurations on the thermal-flow characteristics of gas turbine blades was examined. To investigate the effect of the interference of anti-kidney vortices, the ratios of the pitch distance and hole diameter (P/d=5, 6.25, 8.333) were considered with two different compound angles (λ=0°, 4°). The film cooling performance and the generated losses were studied. Then, the relevant mechanisms were identified and explained. A numerical study was performed using ANSYS CFX 14.5 with the shear stress transport (SST) turbulent model. The blowing ratio was kept at a constant value of M=1.5. The film cooling effectiveness and temperature distribution are graphically depicted with various geometrical configurations.

Design Modification Investigation of a Concept Heat Exchanger for Better Efficiency through Thermal Simulation

2013 ◽  
Vol 631-632 ◽  
pp. 1026-1031
Author(s):  
Tousif Ahmed ◽  
Md. Abu Abrar ◽  
Md. Tanjin Amin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Thermal Simulation ◽  
Attractive Alternative ◽  
Computational Domain ◽  
Thermal Flow ◽  
Design Modification ◽  
Compact Design

Thermal flow simulation can be used to study the fluid flow and heat transfer for a wide variety of engineering equipment. Flow simulations with the advent of computer architectures with superfast processing capabilities are rapidly emerging as an attractive alternative to conventional thermal flow analysis which is either too restrictive or expensive. In thermodynamic applications, increase of thermal efficiency of heat exchangers (i.e. radiators, cooling towers, condensers, intercoolers) is essential for compact design and improving whole cycle efficiency thus improving economic viability of the system. This paper outlines the process taken to optimize the geometry of conventional heat exchanger. Models were drawn into Solidworks and a computational domain was created. Solidworks Thermal Simulation was used to iterate toward a converged solution with the goal of obtaining a better efficiency of the heat exchanger. The results are analyzed and compared between two differently designed heat exchangers to find out the improvements. These practices were detailed in hopes that further research would use the ground work laid out in this paper to redesign existing heat exchangers.

Solution Adaptive Grids Applied to Low Reynolds Number Flow

2002 ◽  
Author(s):  
Govert de With ◽  
Arne E. Holdo̸ ◽  
Thomas A. Huld
Keyword(s):  
Numerical Study ◽  
Turbulent Viscosity ◽  
Flow Simulation ◽  
Mesh Size ◽  
Adaptive Grids ◽  
Adaptation Algorithm ◽  
Flow Around A Cylinder ◽  
Reynolds Number Flow ◽  
Number Flow ◽  
Mesh Structures

A numerical study has been undertaken to investigate the use of a solution adaptive grid for flow around a cylinder in the laminar flow regime. The main purpose of this work is twofold. The first aim is to investigate the suitability of a grid adaptation algorithm and the reduction in mesh size that can be obtained. Secondly, the uniform asymmetric flow structures are ideal to validate the mesh structures due to mesh refinement and consequently the selected refinement criteria. The refinement criteria in this work are derived from turbulent viscosity, which is not applied to the flow simulation, but instead used as a measure for grid refinement.

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