scholarly journals Modelling of Heat Transfer at the Solid to Solid Interface

2016 ◽  
Vol 61 (1) ◽  
pp. 341-346 ◽  
Author(s):  
M. Rywotycki ◽  
Z. Malinowski ◽  
J. Falkus ◽  
K. Sołek ◽  
A. Szajding ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Objective Function ◽  
Boundary Surface ◽  
Physical Experiment ◽  
Work Piece ◽  
Error Norm ◽  
Solid Interface ◽  
Two Samples

In technological process of steel industry heat transfer is a very important factor. Heat transfer plays an essential role especially in rolling and forging processes. Heat flux between a tool and work piece is a function of temperature, pressure and time. A methodology for the determination of the heat transfer at solid to solid interface has been developed. It involves physical experiment and numerical methods. The first one requires measurements of the temperature variations at specified points in the two samples brought into contact. Samples made of C45 and NC6 steels have been employed in physical experiment. One of the samples was heated to an initial temperature of: 800°C, 1000°C and 1100°C. The second sample has been kept at room temperature. The numerical part makes use of the inverse method for calculating the heat flux and at the interface. The method involves the temperature field simulation in the axially symmetrical samples. The objective function is bulled up as a dimensionless error norm between measured and computed temperatures. The variable metric method is employed in the objective function minimization. The heat transfer coefficient variation in time at the boundary surface is approximated by cubic spline functions. The influence of pressure and temperature on the heat flux has been analysed. The problem has been solved by applying the inverse procedure and finite element method for the temperature field simulations. The self-developed software has been used. The simulation results, along with their analysis, have been presented.

scholarly journals Spatiotemporal distribution of the temperature field inside the thin heated foil during impacting liquid spray

2021 ◽  
Vol 2119 (1) ◽  
pp. 012171
Author(s):  
V V Cheverda ◽  
T G Gigola ◽  
P M Somwanshi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Infrared Image ◽  
Image Sequence ◽  
Spatiotemporal Distribution ◽  
Average Heat Transfer Coefficient ◽  
Average Heat ◽  
Liquid Spray

Abstract The spatiotemporal distribution of the temperature inside a constantan foil during impacting spray is resolved experimentally in the present work. The received infrared image sequence will be used to find the local and average heat transfer coefficient of the foil. In the future, the results obtained will be used to calculate the heat flux in the region of the contact line of each drop.

scholarly journals A Theorem for Finding Maximum Temperature in Wet Grinding

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
J. L. González-Santander ◽  
G. Martín
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Integral Form ◽  
Stationary Regime ◽  
Time Dependent ◽  
Maximum Temperature ◽  
Theoretical Computation ◽  
Constant Heat ◽  
Workpiece Surface

We consider the solutions found in the literature for heat transfer in surface grinding, assuming a constant heat transfer coefficient for the coolant acting on the workpiece surface and a constant or linear heat flux profiles entering into the workpiece. From the integral form of the time-dependent temperature field reached in the workpiece, assuming the previous conditions, we prove that the maximum temperature always occurs in the stationary regime on the workpiece surface within the contact zone between the wheel and the workpiece. This result assures a very rapid method for the theoretical computation of the maximum temperature.

HEAT TRANSFER INVESTIGATION FOR A MULTILAYER INSULATION SYSTEM VIA RADIATIVE-CONDUCTIVE APPROACH UNDER LOW TEMPERATURE CONDITIONS IN SPACE

2020 ◽  
Vol 19 (2) ◽  
pp. 70
Author(s):  
G. N. Lacerda ◽  
M. F. Curi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Insulation System ◽  
Final Temperature ◽  
Space Applications ◽  
Conduction Heat Transfer ◽  
Stationary Temperature Field ◽  
Layer Density ◽  
Multilayer Insulation

Thermal insulation is an important area, not restricted to mechanical engineering, but widely studied in environmentalissues, such as global warming and, above all, energy-saving, since controlling the heat flux on microprocessorsthrough temperature control on components in space applications. This work focuses on controlling the temperature incomponents that could not lose or gain so much heat in space, especiallywhen the overall safety of sending satellites onspecific missions is required. To ensure that, Multilayer Insulation (MLI) is used. With fluid mechanics and radiation-conductionheat transfer theory, it was possible to calculate the transient and stationary temperature field and heat flux inMLI. The boundary temperatures are specified at 300K and 4K. The results, from solving the resulting discretized ODE,simulated with fsolve and odeintScipy subroutines in Python, able to solve the equations numerically, were shown. Thedata given by the simulation was able to indicate the impacts of varying the layer density, emissivity of screen, the distancebetween screens and the perforation coefficient in stationary and transient approaches. A way to simulate the performanceof MLI numerically was presented. Modifying emissivity (e) showed variations higher than in the perforation coefficient(ξ). Layer density controls the distance between layers (d ), changing the conduction heat transfer. In the transient casesimulation, it was possible to notice that varying parameters impact in time to reach steady-state and final temperature.

scholarly journals Calculation of Some Integrals Arising in Heat Transfer in Geothermics

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
J. L. G. Santander ◽  
P. Castañeda Porras ◽  
J. M. Isidro ◽  
P. Fernández de Córdoba
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Heat Exchanger ◽  
Ambient Temperature ◽  
Periodic Oscillation ◽  
Field Evaluation ◽  
Borehole Heat Exchanger

We calculate some integrals involved in the temperature field evaluation of the ground, heated by a borehole heat exchanger. This calculation allows a faster computation of that component of the temperature field which involves the periodic oscillation of the ambient temperature or the ambient heat flux.

scholarly journals Method for Determining the Boundary Condition of Heat Transfer in Mold for Slab Casting

2021 ◽  
Vol 2101 (1) ◽  
pp. 012037
Author(s):  
Junli Guo ◽  
Jin Zou ◽  
Changlin Yang ◽  
Deping Lu ◽  
Lefei Sun
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Heat Flux ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Casting Speed ◽  
Cooling Condition ◽  
Average Heat Transfer Coefficient ◽  
Average Heat

Abstract The calculation of temperature field in the mold is important for the study of solidification process of liquid steel. In order to calculate the accurate temperature field of slab in the mod, the boundary condition of heat transfer in the mold should be determined before the calculation of slab temperature. In this paper, the relationship among the average heat transfer coefficient in the mold, the physical properties of steel, the cast condition and the cooling condition is derived according to the energy conservation equation and the Fourier law of heat conduction. Furthermore, the method for determining the parameters related to the formula of boundary heat flux is introduced. Results indicate that the average heat transfer coefficient in the mold ranges from 450 to 2000 W·(m2oC)−1 for conventional caster with a casting speed ranging from 0.8 and 1.8 m·min-1. The average heat transfer coefficient increases with the increase of casting speed. Besides, the casting speed has an effect on the parameters in the formula of calculating boundary heat flux, which indicates that the casting speed and the cooling condition should be taken into consideration for determining parameters related to the formula of calculating surface heat flux in the mold.

DNS of Conjugate Heat Transfer Phenomena With an Improved IB Method

2011 ◽  
Author(s):  
Seongwon Kang
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Circular Cylinder ◽  
Conjugate Heat Transfer ◽  
Bluff Body ◽  
Transfer Problem ◽  
Heat Transfer Problem ◽  
Reconstruction Method ◽  
Solid Interface ◽  
Ib Method

In the present study, the immersed boundary (IB) method is applied as a tool to solve a conjugate heat transfer problem in a turbulent flow around a circular cylinder. This problem involves complexities such as transition, turbulent natural convection, and interaction of fluid convection and solid conduction. In order to enforce the velocity boundary condition at the IB, a second-order reconstruction method is employed. In order to handle coupling of the temperature field between different materials, the fluid-solid interface is approximated as a group of adjoining Cartesian faces from heterogeneous material regions. A Hermite-type interpolation is applied to reconstruct the temperature field across the fluid-solid interface with a reduced error. This approach has been verified with a heat transfer problem with an analytic solution and shows an improved result compared to the previous method. For the turbulent conjugate heat transfer problem around a circular cylinder, the predicted local Nusselt number shows a good agreement with the previous experiment. The statistical data obtained from this simulation can be used for turbulence modeling of heat transfer problems around a bluff body.

Application of adjustment calculus to the Trefftz method for calculating temperature field of the boiling liquid flowing in a minichannel

2014 ◽  
Vol 24 (4) ◽  
pp. 811-824 ◽  
Author(s):  
Sylwia Hożejowska ◽  
Robert Kaniowski ◽  
Mieczysùaw E. Poniewski
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Fields ◽  
Direct And Inverse Problems ◽  
Trefftz Method ◽  
Content Type ◽  
Boiling Liquid

Purpose – The purpose of this paper is to focus on the application of the Trefftz method to the calculation of the two-dimensional (2D) temperature field in the boiling refrigerant flow through an asymmetrically heated vertical minichannel with a rectangular cross-section. The considerations were limited to determining the temperature of the continuous phase – liquid for bubbly and bubbly-slug flow. The numerical solution found with the Trefftz methods was compared with the simplified solution. For nucleate boiling, heat transfer coefficient at the heating foil – liquid contact was determined. Design/methodology/approach – The Trefftz method was used to determine 2D temperature distributions for the glass pane, the heating foil and the boiling liquid. The temperature fields were approximated by the sum of the particular solution and the linear combination of suitable Trefftz functions. Coefficients of linear combination were computed using experimental data, including heating foil temperature measurements obtained with the liquid-crystal method and experimentally determined void fraction. The computations were based on the Trefftz method supplemented with the adjustment calculus. Findings – The way of solving direct and inverse problems of heat conduction in solid bodies (isolating glass, heating foil) and in liquids (boiling refrigerant flowing through the minichannel) was presented. For the first time, both 2D temperature fields for the heating foil and the boiling liquid were calculated while simultaneously using the Trefftz method. The known temperature values of the foil and liquid allowed the calculation of the heat transfer coefficient and the heat flux at the heating foil-liquid contact. Adjustment calculus implemented into the Trefftz method was used to smooth the measurement data and to reduce their errors. Practical implications – The approach proposed in the paper can be applied to determining 2D temperature field, heat flux and heat transfer coefficient in direct and inverse problems concerning two-phase flowing miniature compact heat exchangers. Originality/value – The paper presents a novel implementation of the Trefftz method to simultaneous solving an inverse problem in the heating foil and the contacting flowing liquid.

Heat Transfer of Bottom Tubes in Delayed Coking Furnace: Simulation and Measurement

2012 ◽  
Vol 560-561 ◽  
pp. 1146-1151
Author(s):  
Jun Wei Yang ◽  
Lan Juan Wang ◽  
Jia Zhi Xiao ◽  
Chao He Yang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Field ◽  
Hot Spot ◽  
Industrial Testing ◽  
Jet Flame ◽  
Delayed Coking ◽  
Testing Data ◽  
Entrainment Zone ◽  
Good Agreement

Adding tubes on the bottom of delayed coking furnace is an useful measure for enhancing the throughput, but the distance between tubes and burners is too small to conform design standard. The security of these bottom tubes is uncertain. The processes of turbulence, combustion and heat transfer in the furnace were simulated by numerical method. Detailed information of velocity field, temperature field and heat flux was obtained. The heat transfer of tubes in entrainment zone of jet flame was investigated. The possibility of tube oxidation and hot spot was also discussed. Results show that the bottom tubes are security, which located in the low temperature field and the range of heat flux is 22~45 kW/m2. The results are in good agreement with industrial testing data.

Influence of Glass Coating Thickness on Interfacial Heat Transfer Coefficient during Forming of Nickel Based Superalloys

2013 ◽  
Vol 750 ◽  
pp. 104-107
Author(s):  
Markus Busuttil ◽  
Yu Pei Lin ◽  
Jean Christophe Gebelin ◽  
Roger C. Reed
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Numerical Modeling ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Coating Thickness ◽  
Work Piece ◽  
Interfacial Heat Transfer Coefficient ◽  
Glass Coating ◽  
Interfacial Heat Transfer

The influence of glass coating thickness on the interfacial heat transfer coefficient has been examined using numerical modeling. Temperature and heat flux during working of a Inconel 718 work-piece and colder H13 dies have been simulated. The thickness of the glass coating is found to have a significant influence on the forming characteristic.

The Overview of Modeling the Thermo-Mechanical Three Dimensional Friction Stir Welding Process

2011 ◽  
Vol 189-193 ◽  
pp. 2129-2133 ◽  
Author(s):  
Mei Ling Jiang ◽  
Min Wang ◽  
Dong Chen
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Mechanical Model ◽  
Three Dimensional ◽  
Welding Process ◽  
Velocity Fields ◽  
Work Piece ◽  
Friction Stir ◽  
Backing Plate ◽  
Accurate Temperature

A three dimensional thermo-mechanical model for FSW is presented. It's based on the model proposed by Alma H. Oliphant et al.[1] and Jacquin, D.et al.[2]. Velocity fields and initial plunge temperature profile are introduced in the steady state calculation of the temperature field during welding. And the non-adiabatic heat transfer conditions between the tool, the work piece, and the backing plate are also applied to the model. So a more accurate temperature will be got. It is anticipated that the model can be extended to optimize the FSW process parameters.

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