A numerical study to investigate the effect of turbulators on thermal flow and heat performance of a 3D pipe

Heat Transfer ◽  
2021 ◽  
Author(s):  
Jassim Alhamid ◽  
Ahmed Ramadhan Al‐Obaidi ◽  
H. Towsyfyan
Keyword(s):  
Numerical Study ◽  
Thermal Flow

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.

Numerical Study of Pressure Loss in Ceramic Bed of Thermal Flow Reversal Reactor

2013 ◽  
Vol 655-657 ◽  
pp. 149-153
Author(s):  
Zhen Qiang Gao ◽  
Rui Xiang Liu ◽  
Yong Qi Liu
Keyword(s):  
Pressure Loss ◽  
Static Pressure ◽  
Pressure Field ◽  
Numerical Study ◽  
Volume Flow Rate ◽  
Flow Reversal ◽  
Thermal Flow ◽  
Dimensional Model ◽  
Model Fluid ◽  
Main Factors

This paper describes the use of a commercial CFD code, FLUENT, to model fluid flow in thermal flow reversal reactor (TFRR) for lean methane oxidation. A two dimensional model is used. Pressure loss in ceramic bed of TFRR was focused on, and the effects of main factors are presented. The results show that the contours of static pressure in ceramic bed are slightly inclined due to the gradually variation distribution of velocity; the pressure field in distributing header is more uniform than that of collecting header; the ratio of header’s height to ceramic length influences the pressure loss most and with the increase of the ratio the pressure loss of TFRR decreased dramatically; the pressure loss increased with the increase of volume flow rate. The structure of headers is the most important factor which affects the pressure loss of TFRR.

Numerical Study on Thermal-flow Characteristics by Solar Radiation for Single-span Greenhouse

2018 ◽  
Vol 19 (3) ◽  
pp. 208-217
Author(s):  
Jonghyuk Yoon ◽  
Youngbae Kim ◽  
In Ho Yu ◽  
Jong Won Lee ◽  
Hyoungwoon Song
Keyword(s):  
Solar Radiation ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Thermal Flow

scholarly journals Numerical study on aerodynamic characteristics of high-speed trains with considering thermal-flow coupling effects

2017 ◽  
Vol 19 (7) ◽  
pp. 5606-5626 ◽  
Author(s):  
Hong Wei Xing ◽  
Ai Min Yang ◽  
Yi Fan Li ◽  
Ling Zhang ◽  
Li Jing Feng ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Aerodynamic Characteristics ◽  
Thermal Flow ◽  
Coupling Effects ◽  
Flow Coupling ◽  
High Speed Trains

scholarly journals Numerical Study on Heat Distribution and Transfer Characteristics of a Manifold in a Coal Mine VAM TFRR Oxidation Bed

2015 ◽  
Vol 9 (1) ◽  
pp. 687-696 ◽  
Author(s):  
Zongli Li ◽  
Yongqi Liu ◽  
Jinhui Han ◽  
Zhiming Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Maximum Error ◽  
Flow Reversal ◽  
Thermal Flow ◽  
Hot Gas ◽  
Coupled Heat Transfer ◽  
Homogeneous Porous Media ◽  
Fluent Software ◽  
Starting Process

A thermal flow-reversal reactor is candidate for utilizing low concentration ventilation air methane. In this paper, a numerical study is performed by using the FLUENT software to explore the details of the transient preheating and starting process of the thermal flow-reversal reactor oxidation bed. The bed was heated by hot gas, which was transported and distributed through the holes of manifolds to the middle of the bed. The homogeneous porous media and coupled heat transfer models were chosen; and the mass and heat flow distributions passing through the holes, the heat transfer on the outer surface of the manifold and the temperature distribution of the bed were calculated. The results indicate that the heat of the hot gas passing through the holes decreases gradually along the direction of the hot gas flowing in the manifold, causing the temperature of the bed decrease accordingly. The calculated temperatures of the oxidation bed are compared with the tested results. The maximum error between the calculation and the test was 8.9%.

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