Novel inverse heat transfer methodology for estimation of unknown interfacial heat flux of a continuous casting mould: A complete three-dimensional thermal analysis of an industrial slab mould

2021 ◽  
Vol 160 ◽  
pp. 106648
Author(s):  
Ananda S. Vaka ◽  
Suvankar Ganguly ◽  
Prabal Talukdar
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Heat Flux ◽  
Continuous Casting ◽  
Three Dimensional ◽  
Inverse Heat Transfer ◽  
Interfacial Heat Flux ◽  
Continuous Casting Mould

Numerical Simulation Of A Microchannel For Microelectronic Cooling

2012 ◽  
Author(s):  
Wai Hing Wong ◽  
Normah Mohd. Ghazali
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Flux ◽  
Aspect Ratio ◽  
Three Dimensional ◽  
Large Temperature ◽  
Rectangular Microchannel ◽  
Numerical Work ◽  
Solid Region ◽  
Wall Interaction

Kertas kerja ini membincangkan simulasi berangka ke atas sinki haba saluran mikro dalam penyejukan alatan mikroelektronik. Model Dinamik Bendalir Berkomputer (CFD) tiga dimensi dibina menggunakan pakej komersil, FLUENT, untuk mengkaji fenomenon aliran bendalir dan pemindahan haba konjugat di dalam suatu sinki haba segi empat yang diperbuat daripada silikon. Model ditentusahkan dengan keputusan daripada uji kaji dan pengkajian berangka yang lepas untuk lingkungan nombor Reynolds kurang daripada 400 berdasarkan diameter hidraulik 86 mm. Kajian ini mengambil kira kesan kelikatan bendalir yang bersandaran dengan suhu dan keadaan aliran pra–membangun dari segi hidrodinamik dan haba. Model memberi maklumat tentang taburan suhu dan fluks haba yang terperinci di dalam sinki haba saluran mikro. Kecerunan suhu yang tinggi dicatat pada kawasan pepejal berdekatan dengan sumber. Fluks haba paling tinggi didapati pada dinding tepi saluran mikro diikuti oleh dinding atas dan bawah. Purata pekali pemindahan haba yang lebih tinggi bagi silikon menjadikan ia bahan binaan sinki haba saluran mikro yang lebih baik berbanding dengan kuprum dan aluminium. Peningkatan nisbah aspek saluran mikro yang bersegi empat memberi kecekapan penyejukan yang lebih tinggi kerana kelebaran saluran yang berkurangan memberi kecerunan halaju yang lebih tinggi dalam saluran. Nisbah aspek yang optimum yang diperoleh adalah dalam lingkungan 3.7 – 4.1. Kata kunci: Saluran mikro, CFD, FLUENT, simulasi berangka, penyejukan mikroelektron The paper discusses the numerical simulation of a micro–channel heat sink in microelectronics cooling. A three–dimensional Computational Fluid Dynamics (CFD) model was built using the commercial package, FLUENT, to investigate the conjugate fluid flow and heat transfer phenomena in a silicon–based rectangular microchannel heatsink. The model was validated with past experimental and numerical work for Reynolds numbers less than 400 based on a hydraulic diameter of 86 mm. The investigation was conducted with consideration of temperaturedependent viscosity and developing flow, both hydrodynamically and thermally. The model provided detailed temperature and heat flux distributions in the microchannel heatsink. The results indicate a large temperature gradient in the solid region near the heat source. The highest heat flux is found at the side walls of the microchannel, followed by top wall and bottom wall due to the wall interaction effects. Silicon is proven to be a better microchannel heatsink material compared to copper and aluminum, indicated by a higher average heat transfer. A higher aspect ratio in a rectangular microchannel gives higher cooling capability due to high velocity gradient around the channel when channel width decreases. Optimum aspect ratio obtained is in the range of 3.7 – 4.1. Key words: Microchannel, CFD, FLUENT, numerical simulation, microeletronics cooling

Heat transfer of three-dimensional micropolar fluid on a Riga plate

2020 ◽  
Vol 98 (1) ◽  
pp. 32-38 ◽  
Author(s):  
S. Nadeem ◽  
M.Y. Malik ◽  
Nadeem Abbas
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Differential Equations ◽  
Surface Temperature ◽  
Ordinary Differential Equations ◽  
Nonlinear Partial Differential Equations ◽  
Three Dimensional ◽  
Nonlinear Ordinary Differential Equations ◽  
Exponential Order ◽  
Riga Plate

In this article, we deal with prescribed exponential surface temperature and prescribed exponential heat flux due to micropolar fluids flow on a Riga plate. The flow is induced through an exponentially stretching surface within the time-dependent thermal conductivity. Analysis is performed inside the heat transfer. In our study, two cases are discussed here, namely prescribed exponential order surface temperature (PEST) and prescribed exponential order heat flux (PEHF). The governing systems of the nonlinear partial differential equations are converted into nonlinear ordinary differential equations using appropriate similarity transformations and boundary layer approach. The reduced systems of nonlinear ordinary differential equations are solved numerically with the help of bvp4c. The significant results are shown in tables and graphs. The variation due to modified Hartman number M is observed in θ (PEST) and [Formula: see text] (PEHF). θ and [Formula: see text] are also reduced for higher values of the radiation parameter Tr. Obtained results are compared with results from the literature.

scholarly journals Improving the Heat Transfer Rate of Air Conditioning Condenser by Material Optimization

2021 ◽  
pp. 39-50
Author(s):  
A. A. Adegbola ◽  
O. A. Adeaga ◽  
A. O. Babalola ◽  
A. O. Oladejo ◽  
A. S. Alabi
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Heat Flux ◽  
Flow Rate ◽  
Transfer Rate ◽  
Air Conditioning ◽  
Static Pressure ◽  
Cfd Analysis ◽  
Condenser Tube ◽  
Total Heat Transfer

Air conditioning systems have condensers that remove unwanted heat from the refrigerant and transfer the heat outdoors. The optimization of the global exploit of heat exchanging devices is still a burdensome task due to different design parameters involved. There is need for more and substantial research into bettering cooling channel materials so as to ensure elevated performance, better efficiency, greater accuracy, long lasting and low cost heat exchanging. The aim of this research work is to improve the heat transfer rate of air conditioning condenser by optimizing materials for different tube diameters. Simulations using thermal analysis and Computational Fluid Dynamic (CFD) analysis were carried out to determine the better material and fluid respectively. The analysis was done using Analysis System software. Different parameters were calculated from the results obtained and graphs are plotted between various parameters such as heat flux, static pressure, velocity, mass flow rate and total heat transfer. The materials used for CFD analysis are R12 and R22, and for thermal analysis are copper and aluminium. From the CFD analysis, the result shows that R22 has more static pressure, velocity, mass flow rate and total heat transfer than R12 at condenser tube diameter 6 mm. In thermal investigation, the heat flux is more for copper material at condenser tube diameter 6 mm. Copper offers maximum heat flux. Also, refrigerant R22 scores maximum for the heat transfer criteria, but cannot be recommended due to toxicity

scholarly journals A Three-Dimensional Coupled Internal/External Simulation of a Film-Cooled Turbine Vane

1999 ◽  
Author(s):  
James D. Heidmann ◽  
David L. Rigby ◽  
Ali A. Ameri
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Film Cooling ◽  
Three Dimensional ◽  
High Heat ◽  
Operating Conditions ◽  
High Heat Flux ◽  
Nasa Lewis Research ◽  
Turbine Vane ◽  
Film Cooling Holes

A three-dimensional Navier-Stokes simulation has been performed for a realistic film-cooled turbine vane using the LeRC-HT code. The simulation includes the flow regions inside the coolant plena and film cooling holes in addition to the external flow. The vane is the subject of an upcoming NASA Lewis Research Center experiment and has both circular cross-section and shaped film cooling holes. This complex geometry is modeled using a multi-block grid which accurately discretizes the actual vane geometry including shaped holes. The simulation matches operating conditions for the planned experiment and assumes periodicity in the spanwise direction on the scale of one pitch of the film cooling hole pattern. Two computations were performed for different isothermal wall temperatures, allowing independent determination of heat transfer coefficients and film effectiveness values. The results indicate separate localized regions of high heat flux in the showerhead region due to low film effectiveness and high heat transfer coefficient values, while the shaped holes provide a reduction in heat flux through both parameters. Hole exit data indicate rather simple skewed profiles for the round holes, but complex profiles for the shaped holes with mass fluxes skewed strongly toward their leading edges.

3D Thermo-Mechanical Modelling of Wheel and Belt Continuous Casting

2011 ◽  
Vol 693 ◽  
pp. 235-244 ◽  
Author(s):  
John F. Grandfield ◽  
Sébastien Dablement ◽  
Hallvard Gustav Fjær ◽  
Dag Mortensen ◽  
Michael Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Three Dimensional ◽  
Casting Process ◽  
Liquid Pool ◽  
Air Gap ◽  
Temperature Measurements ◽  
Heat Extraction ◽  
Gap Formation ◽  
Solidification Defects

Wire rod is produced by hot-rolling a bar of metal coming from a wheel/belt continuous casting process. This kind of process, e.g. Properzi, is an elaborate process in which the molten metal is poured in a cooled rotating mould formed by the groove of a wheel and closed by a belt. In order to better understand the heat transfer phenomenon and solidified bar characteristics, depending on process parameters a three dimensional thermo-mechanical model has been developed. The model, based on the finite-element method, calculates the heat transfer coefficient of the air gap at the metal-mould interface as a function of the size of the gap determined by the bar contraction and wheel and belt thermal deformations. The air gap formation due to metal shrinkage and mould deformation is the main factor which determines the heat extraction. Wheel temperature measurements with thermocouple and belt temperature measurements with an infrared system were carried out to verify model results. Attempts were also made to measure a liquid pool profile using doping with copper rich alloy. The model shows the effect of the casting temperature and the rotation speed on the air gap formation and resulting temperature and stress fields. The model can be applied to issues such as maximising wheel and belt life and minimising solidification defects.

Effect of Edge Conditions on Natural Convective Heat Transfer From a Narrow Vertical Flat Plate With a Uniform Surface Heat Flux

2007 ◽  
Author(s):  
Patrick H. Oosthuizen ◽  
Jane T. Paul
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Surface Heat Flux ◽  
Three Dimensional ◽  
Surface Heat ◽  
Heated Plate ◽  
Two Dimensional ◽  
Adiabatic Surface

Two-dimensional natural convective heat transfer from vertical plates has been extensively studied. However, when the width of the plate is relatively small compared to its height, the heat transfer rate can be greater than that predicted by these two-dimensional flow results. Because situations that can be approximately modelled as narrow vertical plates occur in a number of practical situations, there exists a need to be able to predict heat transfer rates from such narrow plates. Attention has here been given to a plate with a uniform surface heat flux. The magnitude of the edge effects will, in general, depend on the boundary conditions existing near the edge of the plate. To examine this effect, two situations have been considered. In one, the heated plate is imbedded in a large plane adiabatic surface, the surfaces of the heated plane and the adiabatic surface being in the same plane while in the second there are plane adiabatic surfaces above and below the heated plate but the edge of the plate is directly exposed to the surrounding fluid. The flow has been assumed to be steady and laminar and it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated by using the Boussinesq approach. It has also been assumed that the flow is symmetrical about the vertical centre-plane of the plate. The solution has been obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in terms of dimensionless variables. Results have only been obtained for a Prandtl number of 0.7. A wide range of the other governing parameters have been considered for both edge situations and the conditions under which three dimensional flow effects can be neglected have been deduced.

The Mould Flux Heat Conduction Performance Designing of High Carbon Steel for Thin Slab Continuous Casting

2014 ◽  
Vol 1033-1034 ◽  
pp. 1313-1316
Author(s):  
Hui Rong Li ◽  
Li Gen Sun ◽  
Li Qun Ai
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Carbon Steel ◽  
Continuous Casting ◽  
Orthogonal Experiment ◽  
High Carbon Steel ◽  
Thin Slab ◽  
High Carbon ◽  
Slab Continuous Casting ◽  
Mould Flux

Heat transfer of the mould flux between the mould and the strand is very complicated, especially for the high carbon steel thin slab continuous casting. In this research the orthogonal experiment has been carried out, and the results showed that: the effect for the heat flux form strong to weak is: R>Na2O>F>MgO>BaO. and in the experiment range, with the R increasing, when the R, Na2O content and the F- content are increasing, the heat flux would be decreasing; with the MgO content increasing, the crystallization temperature would getting fluctuant; with the BaO content increasing, the heat flux would getting fluctuant, when its content is around 6%, the heat flux is reach its summit.

scholarly journals Comparison of Four Models of Radiative Heat Transfer Between Flat Surface to Evaluate the Temperature Field Based on Example of the Continuous Casting Mould

2015 ◽  
Vol 60 (1) ◽  
pp. 209-213
Author(s):  
M. Rywotycki ◽  
Z. Malinowski ◽  
K. Miłkowska-Piszczek ◽  
A. Gołdasz ◽  
B. Hadała
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Casting Process ◽  
Cooling Zone ◽  
The Finite Element Method ◽  
Cast Slab ◽  
Continuous Casting Mould ◽  
Heat Transfer By Radiation

AbstractThe paper presents the results of research concerning the influence of radiative heat transfer on the strand and mould interface. The four models for determining the heat transfer boundary conditions within the primary cooling zone for the continuous casting process of steel have been presented. A cast slab - with dimensions of 1280×220 mm - has been analysed. Models describing the heat transfer by radiation have been specified and applied in the numerical calculations. The problem has been solved by applying the finite element method and the self-developed software. The simulation results, along with their analysis, have been presented. The developed models have been verified based on the data obtained from the measurements at the industrial facility.

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