3D Heat Conductivity Model of Mold Based on Node Temperature Inheritance

2019 ◽  
Vol 38 (2019) ◽  
pp. 92-100 ◽  
Author(s):  
Pengcheng Xiao ◽  
Zengxun Liu ◽  
Liguang Zhu ◽  
Zepeng Wang ◽  
Zhanlong Piao
Keyword(s):  
Heat Transfer ◽  
Shell Thickness ◽  
Transient State ◽  
Measured Data ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Conductive Heat ◽  
Scale Thickness ◽  
Mold Deformation ◽  
Copper Wall

AbstractA novel 3D conductive heat transfer model was developed based on node temperature inheritance. Heat transfer of the mold and billet could be analyzed synchronously. In the model, heat transfer in the copper wall was in a steady state, whereas heat transfer in the billet was in a transient state. The temperature distribution indicated that the maximum temperature on the copper wall reached approximately 30 mm below the meniscus. The results were in better agreement with industrially measured data than those of traditional 2D heat transfer models. The model was applied to study the effect of water scale on heat transfer of a billet mold. When the scale thickness increased from 0 to 0.5 mm, the maximum temperature on the copper wall increased from 174 °C to 364 °C, which will lead to mold deformation and peeling of the coating. In addition, the shell thickness slightly decreased with increasing scale thickness.

Nondegeneracy of optimality conditions in control problems for a radiative–conductive heat transfer model

2016 ◽  
Vol 289 ◽  
pp. 371-380 ◽  
Author(s):  
Alexander Yu. Chebotarev ◽  
Andrey E. Kovtanyuk ◽  
Gleb V. Grenkin ◽  
Nikolai D. Botkin ◽  
Karl-Heinz Hoffmann
Keyword(s):  
Heat Transfer ◽  
Optimality Conditions ◽  
Heat Transfer Model ◽  
Conductive Heat Transfer ◽  
Control Problems ◽  
Transfer Model ◽  
Conductive Heat

A Two-Dimensional Conjugate Heat Transfer Model for Forced Air Cooling of an Electronic Device

1989 ◽  
Vol 111 (1) ◽  
pp. 41-45 ◽  
Author(s):  
A. Zebib ◽  
Y. K. Wo
Keyword(s):  
Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Electronic Device ◽  
Transfer Problem ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Air Cooling ◽  
Two Dimensional ◽  
Component Design ◽  
Forced Air

Thermal analysis of forced air cooling of an electronic component is modeled as a two-dimensional conjugate heat transfer problem. The velocity field in a constricted channel is first computed. Then, for a typical electronic module, the energy equation is solved with allowance for discontinuities in the thermal conductivity. Variation of the maximum temperature with the average air velocity is presented. The importance of our approach in evaluating possible benefits due to changes in component design and the limitations of the two-dimensional model are discussed.

Combined Conduction and Radiation Heat Transfer in Porous Materials Heated by Intense Solar Radiation

1985 ◽  
Vol 107 (1) ◽  
pp. 29-34 ◽  
Author(s):  
L. K. Matthews ◽  
R. Viskanta ◽  
F. P. Incropera
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Plane Layer ◽  
Single Scattering ◽  
Dominant Mode ◽  
Radiative Properties ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Radiation Heat ◽  
Flux Approximation

An analysis is presented to predict the heat transfer characteristics of a plane layer of a semitransparent, high-temperature, porous material which is irradiated by an intense solar flux. A transient, combined conduction and radiation heat transfer model, which is based on a two-flux approximation for the radiation, is used to predict the temperature distribution and heat transfer in the material. Numerical results have been obtained using thermophysical and radiative properties of zirconia as a typical material. The results show that radiation is an important mode of heat transfer, even when the opacity of the material is large (τL > 100). Radiation is the dominant mode of heat transfer in the front third of the material and comparable to conduction toward the back. The semitransparency and high single scattering albedo of the zirconia combine to produce a maximum temperature in the interior of the material.

Cooling of Concentrator Photovoltaic Cells Using Mini-Scale Jet Impingement Heat Sinks

2018 ◽  
Author(s):  
Ali Radwan ◽  
Meshack Hawi ◽  
Mahmoud Ahmed
Keyword(s):  
Heat Transfer ◽  
Flow Model ◽  
Three Dimensional ◽  
Jet Impingement ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Cell Temperature ◽  
Maximum Cell ◽  
T System

In this study, an efficient cooling technique for concentrator photovoltaic (CPV) cells is proposed to enhance the system electrical efficiency and extend its lifetime. To do this, a comprehensive three-dimensional conjugate heat transfer model of CPV cells layers coupled with the heat transfer and fluid flow model inside jet impingement heat sink is developed. Four different jet impingement designs are compared. The investigated designs are (A) central inlet jet, (B) Hypotenuse inlet jet, (C) staggered inlet jet, and (D) conventional jet impingement design with side drainage. The effect of coolant flowrate on the CPV/T system performance is investigated. The model is numerically simulated and validated using the available experiments. The performance of CPV system is investigated at solar concentration ratios of 20 and coolant flowrate up to 6000g/min. It is found that increasing the flowrate from 60 g/min to 600 g/min decrease the maximum cell temperature by 31°C for the configuration D while increasing the flowrate from 600 g/min to 6000 g/min reduce the cell temperature by 20.2°C. It is also concluded that at a higher flowrate of 6000g/min, all the investigated configurations relatively achieve better temperature uniformity with maximum temperature differences of 0.9 °C, 2.1 °C, 3.6 °C, and 3.9 °C for configurations A, B, C, and D respectively.

Piston-Liner Thermal Resistance Model for Diesel Engine Simulation: Part 1: Formulation and Tuning

1991 ◽  
Vol 205 (5) ◽  
pp. 343-352 ◽  
Author(s):  
Y Rasihhan ◽  
F J Wallace
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Thermal Resistance ◽  
Direct Injection ◽  
Transfer Model ◽  
Conductive Heat ◽  
Axially Symmetric ◽  
Engine Simulation ◽  
Axial Movement ◽  
Resistance Model

A simple, effective and computationally economical piston-liner thermal resistance model for diesel engine simulation is described. In the model, the detailed shape of the piston and its axial movement and interaction with liner nodes are all taken into account. An imaginary node within the piston provides the necessary temperature difference between the piston and the liner nodes for conductive heat transfer, which is expected to reverse its direction with liner insulation. In the liner, an axially symmetric two-dimensional heat-transfer model is used. Later the piston-liner model is tuned for the experimental single cylinder, direct injection, Petter PH 1W engine used at Bath University, against the experimental piston temperature and liner temperature distribution.

Thermal Model of a Solar Thermochemical Reactor for Metal Oxide Reduction

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Bo Wang ◽  
Lifeng Li ◽  
Johannes J. Pottas ◽  
Roman Bader ◽  
Peter B. Kreider ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Metal Oxide ◽  
Reduction Rate ◽  
Incident Radiation ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Oxide Reduction ◽  
Solar Simulator ◽  
Metal Oxide Reduction ◽  
Solar Thermochemical

Abstract A transient heat transfer model is developed to study the thermal performance of a high-temperature solar thermochemical reactor for metal oxide reduction. The solar reactor consists of an indirectly irradiated tubular fluidized bed contained in a solar cavity receiver. Radiative heat transfer in the cavity, modeled with the Monte Carlo ray-tracing method, is coupled to conduction in the tube and cavity walls. Incident radiation distributions from a diffuse radiative source and a high-flux solar simulator are implemented separately in the model to study the influence of incident radiation directionality on the performance of the reactor. Maximum temperature, maximum thermal stress, start-up time, energy balance, and particle reduction rate for the proposed reactor concept are calculated to inform the design and optimization of a prototype reactor.

Numerical Simulation of Billet Continuous Casting Solidification Based on the Measurement of Shell Thickness and Surface Temperature

2011 ◽  
Vol 80-81 ◽  
pp. 81-85
Author(s):  
Jiao Cheng Ma ◽  
Hui Zhao Sun ◽  
Xue Bin Wang ◽  
Xia Lv
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Surface Temperature ◽  
Shell Thickness ◽  
Casting Machine ◽  
Cooling Water ◽  
Solidification Process ◽  
Transfer Model ◽  
Secondary Cooling ◽  
Billet Continuous Casting

In order to more accurate simulation the solidification of billet continuous casting. The measured shell thickness and surface temperature have been used to revise the heat transfer model. The calculated results of the model are in excellent agreement with the experimental ones based on an actual casting machine. The revised model can excellent to simulate the billet solidification process. So it provides the possibility for better simulation the dynamic solidification process and optimizing of the secondary cooling water.

Statistical Modelling of Bubble Nucleation and Heat Transfer Using Interface Tracking in TransAT CMFD Code

2010 ◽  
Author(s):  
Chidambaram Narayanan ◽  
Siju Thomas ◽  
Djamel Lakehal
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Statistical Modelling ◽  
Nucleate Boiling ◽  
High Heat ◽  
Bubble Nucleation ◽  
Heat Fluxes ◽  
Conductive Heat Transfer ◽  
Transfer Model ◽  
Conductive Heat

This paper presents results of numerical simulations of various processes that demonstrate phase change heat transfer at high heat fluxes using the level-set method. The model used for the purpose has been first validated for the growth of an evaporating bubble in infinite medium, and fim boiling in 2D and 3D. It has then been applied to simulate the nucleation and departure of a single bubble from a solid body subject to conductive heat transfer. Unlike our previous investigations where phase change induced evaporation rate was incorporated like a sub-grid scale heat transfer model applied to the triple contact line, the present work reports simulations with direct phase change modelling by integrating energy fluxes at the interface. The effect of the conductive heat transfer in the solid from which the bubble departs is also taken into account. Comparison with visual images suggests that accounting for conjugate heat transfer is important to capturing micro-hydrodynamics in nucleate boiling, at least qualitatively.

Three Dimensional Transient Heat Transfer Model for Steel Billet Heating in Reheat Furnace

2012 ◽  
Author(s):  
Satish Kumar Dubey ◽  
Neelesh Agarwal ◽  
P. Srinivasan
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Oxide Scale ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Heat Diffusion ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Scale Thickness ◽  
Reheating Process

In steel rolling mills reheat furnaces are used to heat the billets prior to rolling processes. Reheating is one of the most energy intensive processes in the steel industries. Inadequate temperature measuring techniques and extremely complex analytical solution for temperature filed calculations demands suitable numerical model. In the present work a three dimensional transient heat transfer model is developed for billet heating in reheat furnaces. Conduction heat transfer within the billets is modeled using Finite Difference Method (FDM). Fully implicit spatial discretization approximation was used for three dimensional heat diffusion equation of billet. The three dimensional model takes into account the temperature dependent thermo physical properties, reaction heat effect and growing oxide layer. Algorithm is implemented in MATLAB® to solve three dimensional discretization equations. Model is capable of predicting the temperature field for billet and oxide scale thickness for any residence time. The predicted results are in reasonable concurrence with available data. The main objective of this work is to predict billet temperature field and oxide scale thickness for the various residence times, which may be vital for development of energy efficient optimization strategy for reheating process.

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