scholarly journals Experimental Study of Interfacial Heat Flux and Surface Temperature by Inverse Analysis with Thermocouple (Fully Embedded) during Hot Steel Strip Rolling

2012 ◽  
Vol 452-453 ◽  
pp. 959-963 ◽  
Author(s):  
Daniel Weisz-Patrault ◽  
Alain Ehrlacher ◽  
Nicolas Legrand ◽  
Nathalie Labbe ◽  
Jaroslav Horský ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Steel Strip ◽  
Theoretical Models ◽  
Calibration Procedure ◽  
Rolling Process ◽  
Fundamental Aspect ◽  
Strip Rolling ◽  
Interfacial Heat Flux ◽  
Good Agreement

Knowledge of temperature distribution in the roll is fundamental aspect in cold rolling. An inverse analytical method has been previously developed to determine interfacial heat flux and surface temperature by measuring the temperature with a thermocouple (fully embedded) at only one point inside the roll. On this basis some pilot mill tests have been performed. The temperature sensor, the calibration procedure and rolling tests at different strip rolling conditions (5%, 10%, 15% and 20%) are described. Results show a good agreement with well-known theoretical models. Moreover the CPU times of the method (around 0.05 s by cycle) enable an online control of the rolling process.

scholarly journals Experimental Study of Interfacial Heat Flux and Surface Temperature by Inverse Analysis with Thermocouple (Fully Embedded) during Hot Steel Strip Rolling

2012 ◽  
Vol 452-453 ◽  
pp. 959-963 ◽  
Author(s):  
Daniel Weisz-Patrault ◽  
Alain Ehrlacher ◽  
Nicolas Legrand ◽  
Nathalie Labbe ◽  
Jaroslav Horsky ◽  
...  
Keyword(s):  
Experimental Study ◽  
Heat Flux ◽  
Surface Temperature ◽  
Inverse Analysis ◽  
Steel Strip ◽  
Strip Rolling ◽  
Interfacial Heat Flux

Calculation of a Turbulent Boundary Layer Downstream of a Step Change in Surface Temperature

1979 ◽  
Vol 101 (1) ◽  
pp. 144-150 ◽  
Author(s):  
L. W. B. Browne ◽  
R. A. Antonia
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Prandtl Number ◽  
Surface Temperature ◽  
Reynolds Shear Stress ◽  
Turbulent Viscosity ◽  
Step Change ◽  
Mean Temperature ◽  
Thermal Layer ◽  
Good Agreement

Mean temperature and heat flux distributions in a thermal layer that develops within a momentum boundary layer subjected to a step change in surface temperature are calculated using two different methods. The method of Bradshaw and Unsworth, which uses the method of Bradshaw, Ferriss and Atwell to determine the mean velocity and Reynolds shear stress distributions and then assumes a constant turbulent Prandtl number for the heat flux calculation, yields heat flux distributions that are significantly different than the available experimental results at small distances from the step. Good agreement between calculations and experimental values is achieved when the distance x from the step is about 20 δ0, where δ0 is the boundary layer thickness at the step. To obtain good agreement with measurements of heat flux and mean temperature near the step, estimated distributions of turbulent viscosity and effective Prandtl number have been derived using an iterative updating procedure and the calculation method of Patankar and Spalding. These distributions are compared with those available in the literature. Calculated heat flux distributions show that the internal thermal layer is only likely to reach self-preserving conditions when x exceeds 40 δ0.

Analysis and characterisation of ultra-fine ferrite produced during a new steel strip rolling process

1999 ◽  
Vol 40 (4) ◽  
pp. 433-438 ◽  
Author(s):  
P.J. Hurley ◽  
P.D. Hodgson ◽  
B.C. Muddle
Keyword(s):  
Steel Strip ◽  
Rolling Process ◽  
Strip Rolling

Experimental and numerical simulation studies on heat transfer to calorimeters engulfed in diesel pool fires

2017 ◽  
Vol 35 (2) ◽  
pp. 156-176 ◽  
Author(s):  
Sudheer Siddapureddy ◽  
SV Prabhu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Temperature ◽  
Heat Fluxes ◽  
Numerical Code ◽  
Pool Fires ◽  
Steel Pipes ◽  
Adiabatic Surface ◽  
In Fire ◽  
Good Agreement

Characterization of heat transfer to calorimeters engulfed in pool fires is extremely important. To estimate the heat flux to the calorimeters, experiments are performed with horizontal stainless steel 304L pipes engulfed in diesel pool fires. The concept of adiabatic surface temperature is applied to predict the incident heat flux to horizontally oriented calorimeters engulfed in diesel pool fires. Plate thermometers are used to measure the adiabatic surface temperature for diesel pool fires. The estimated subsurface temperatures inside the steel pipes using the adiabatic surface temperature concept and the measured temperatures are in good agreement. Adiabatic surface temperature is also computed from fire simulations. The incident heat fluxes to the steel pipes engulfed in fire predicted from the simulations are found to be in good agreement with the experiments. The fire numerical code is validated against the 1 m pool fire experimental results of centerline temperature distribution and irradiances away from fire. A correlation is provided for the estimation of adiabatic surface temperature for large diesel pool fires. These results would provide an effective way for thermal test simulations.

Rigid Plastic FEM Model of Fast Solution to Strip Rolling

2011 ◽  
Vol 704-705 ◽  
pp. 358-363
Author(s):  
Rui Bin Mei ◽  
Chang Sheng Li ◽  
Xiang Hua Liu ◽  
Li Bao
Keyword(s):  
Rolling Force ◽  
Rolling Process ◽  
Computational Time ◽  
Rolling Schedule ◽  
Strip Rolling ◽  
Rigid Plastic ◽  
Fem Model ◽  
Online Application ◽  
Fast Solution ◽  
Good Agreement

Rigid plastic finite element method (RPFEM) is one of the most efficient numerical methods during the rolling process. Realizing FEM online application has been main target for many researchers. The influence of compile method, elements number, compressible parameter, friction factor and convergent criteria were investigated and RPFEM model of fast solution to strip rolling was proposed in this work. Compile method and compressible parameter have less influence on calculated rolling force. However, the iteration steps are reduced and computational efficiency is improved greatly with compile method of release and compressible parameter 0.01. The change of calculated rolling force becomes less but iteration steps become more and more with the increment of elements number. Both accuracy and efficiency is satisfying with the change of elements number from 50 to 200. In addition, the typical rolling schedule from a certain plant has been solved with the developed program FFEM-2D by FORTRAN. The predicted rolling force has a good agreement with the measured value. The iteration steps change from 12 to 36 and computational time is less than 200(ms) with the model in one pass rolling. Therefore, the accuracy is satisfying and computational time fully meets the basic requirements of FEM online application. Keywords: Rolling; RPFEM; Fast solution; Computational time

Simulation of Thermal Phenomena in Reverse Strip-Rolling Process

2018 ◽  
Vol 941 ◽  
pp. 1424-1430
Author(s):  
Alexander Nam ◽  
Uwe Prüfert ◽  
Marciej Pietrzyk ◽  
Rudolf Kawalla ◽  
Ulrich Prahl
Keyword(s):  
Hot Rolling ◽  
Rolling Process ◽  
Temperature Model ◽  
Hot Strip Rolling ◽  
Forming Process ◽  
Strip Rolling ◽  
Unknown Parameters ◽  
Hot Strip ◽  
Thermal Phenomena ◽  
Good Agreement

In the reverse hot strip rolling, the coiling and uncoiling of the strip leads to unstable conditions during the forming process. Both the temperature of the strip and the dwell time in the coil vary and influence the microstructure evolution passing in the coil during reverse rolling. It makes the design of this process difficult. Therefore, development of the temperature model for the reverse hot rolling including coiling and uncoiling was the main objective of the paper. The identification of the unknown parameters of the boundary conditions is proposed. Methods for their determination are discussed. The analysis is performed on example of the reverse hot rolling of the magnesium alloy AZ31. The resulting temperature model reveals good agreement with thermocouple and pyrometer measurements.

scholarly journals Mathematical Modeling of the Cold Rolling Process and Heat Treatment for DC01 Steel

2021 ◽  
Vol 44 (2) ◽  
pp. 35-38
Author(s):  
Marian-Iulian NEACȘU
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Steel Strip ◽  
Rolling Process ◽  
Recrystallization Annealing ◽  
Strip Rolling ◽  
Active Experiment ◽  
Cold Rolled ◽  
Cold Strip Rolling ◽  
Rolled Tape

The paper presents the elaboration of a mathematical model of the cold strip rolling process combined with the recrystallization annealing after the rolling at LBR Liberty Galati.The elaborated mathematical model allows the prediction of the mechanical properties of cold rolled strips subsequently subjected to a heat treatment.The realization of this mathematical model was based on statistical measurements of the mechanical properties Rm, Rp0.2 (Rc) and A5 for the rolled steel strip DC01 from Liberty Steel Galati. To achieve this mathematical model, the active experiment method was used.With the help of this mathematical model, it is possible to optimize the rolling process by significant savings of time and materials in the process of testing the mechanical properties for cold rolled tape, but also by choosing the most appropriate process parameters.

scholarly journals Time series analysis of water surface temperature and heat flux components in the Itumbiara Reservoir (GO), Brazil

2012 ◽  
Vol 23 (3) ◽  
pp. 245-259 ◽  
Author(s):  
Enner Herenio de Alcântara ◽  
José Luiz Stech ◽  
João Antônio Lorenzzetti ◽  
Evlyn Márcia Leão de Moraes Novo
Keyword(s):  
Heat Flux ◽  
Time Series ◽  
Surface Water ◽  
Surface Temperature ◽  
Water Temperature ◽  
Water Surface ◽  
Surface Water Temperature ◽  
Water Surface Temperature ◽  
Cyclical Pattern ◽  
Good Agreement

AIM: Water temperature plays an important role in ecological functioning and in controlling the biogeochemical processes of the aquatic system. Conventional water quality monitoring is expensive and time consuming. It is particularly challenging for large water bodies. Conversely, remote sensing can be considered a powerful tool to assess important properties of aquatic systems because it provides synoptic and frequent data acquisition over large areas. The objective of this study was to analyze time series of surface water temperature and heat flux to advance the understanding of temporal variations in a hydroelectric reservoir. METHOD: MODIS water-surface temperature (WST) level 2, 1 km nominal resolution data (MOD11L2, version 5) were used. All available clear-sky MODIS/Terra images from 2003 to 2008 were used, resulting in a total of 786 daytime and 473 nighttime images. Time series of surface water temperature was obtained computing the monthly mean in a 3×3 window of three reservoir selected sites: 1) near the dam, 2) at the centre of the reservoir and 3) in the confluence of the rivers. In-situ meteorological data from 2003 to 2008 were used to calculate surface energy budget time series. Cross-wavelet, coherence and phase analysis were carried out to compute the correlation between daytime and nighttime surface water temperatures and the computed heat fluxes. RESULTS: The monthly mean of the day-time WST shows lager variability than the night-time WST. All time series (daytime and nighttime) have a cyclical pattern, passing for a minimum (June - July) and a maximum (December and January). Fourier and the Wavelet Analysis were applied to analyze this cyclical pattern. The daytime time series, presents peaks in 4.5, 6 12 and 36 months and the nighttime WST shows the highest spectral density at 12, 6, 3 and 2 months. The multiple regression analysis shows that for daytime WST, the heat flux terms explain 89% of the annual variation (RMS = 0.89 °C, p < 0.0013). For nighttime, the heat flux terms explain 94% (RMS = 0.53 °C, p < 0.0002). CONCLUSION: The daytime WST and shortwave radiation presents a good agreement for periods of 6 (with shortwave retarded) and 12 months (with shortwave advanced); For nighttime WST and longwave the good agreement is present for 1, 3, 6 and 12 months, all with longwave advanced in relation to WST.

Numerical and Experimental Investigation of Friction in Cold Strip Rolling

2005 ◽  
Author(s):  
Cheng Lu ◽  
A. Kiet Tieu
Keyword(s):  
Experimental Investigation ◽  
Tangential Force ◽  
Frictional Coefficient ◽  
Rolling Process ◽  
Deformation Model ◽  
Strip Rolling ◽  
The Coefficient Of Friction ◽  
Contact Mechanism ◽  
Cold Strip Rolling ◽  
Good Agreement

To obtain a better understanding of friction and contact mechanism in cold strip rolling, a refined asperity ploughing model and an asperity elastic deformation model have been developed. It is found that the asperity angles α1 and α2 significantly affect the tangential force and the coefficient of friction respectively. The theoretical prediction is in good agreement with the experimental results in Ref. [7]. The developed models can predict a reasonable frictional coefficient if it is applied to the cold rolling process.

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