Mathematical Modeling of Transient Flow and Heat Transfer in Gas Stirred Molten Steel

2001 ◽  
Author(s):  
J. L. Xia ◽  
T. Ahokainen
Keyword(s):  
Heat Transfer ◽  
Molten Steel ◽  
Thermal Stratification ◽  
Transient Flow ◽  
Liquid Interface ◽  
Turbulent Dispersion ◽  
Steel Ladle ◽  
Bubble Liquid ◽  
Flow And Heat Transfer ◽  
Heat Transfer Correlations

Abstract Transient two phase flow and heat transfer in a gas-stirred steel ladle are numerically investigated. An Eulerian two fluid approach is used. The drag, lift and turbulent dispersion forces are taken into account for the interface interactions. Different interface heat transfer correlations such as Ranz-Marshall and Hughmark relations are used to examine the influence of heat transfer between gas-liquid interface on the flow. The flow pattern, the histories of both gas and molten steel temperatures, and the thermal stratification history are presented. Results show that gas injection can homogenize thermal field and result in a thermal stratification of about 2 °C only (not complete homogenization). The different heat transfer correlations examined for the bubble-liquid interface have negligible impact on the flow and thermal fields. Predictions are compared with experimental data measured in an industrial ladle and a reasonable agreement is achieved.

Transient Natural Convection Between Two Zones in an Insulated Enclosure

1988 ◽  
Vol 110 (1) ◽  
pp. 116-125 ◽  
Author(s):  
P. A. Litsek ◽  
A. Bejan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Experiments ◽  
Thermal Stratification ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Flow And Heat Transfer ◽  
Vertical Opening ◽  
The Right ◽  
Rayleigh Numbers

The natural convection flow and heat transfer between two enclosures that communicate through a vertical opening is studied by considering the evolution of an enclosed fluid in which the left half is originally at a different temperature than the right half. Numerical experiments show that at sufficiently high Rayleigh numbers the ensuing flow is oscillatory. This and other features are anticipated on the basis of scale analysis. The time scales of the oscillation, the establishment of thermal stratification, and eventual thermal equilibrium are determined and tested numerically. At sufficiently high Rayleigh numbers the heat transfer between the communicating zones is by convection, in accordance with the constant-Stanton-number trend pointed out by Jones and Otis (1986). The range covered by the numerical experiments is 102 < Ra < 107, 0.71 < Pr < 100, and 0.25 < H/L < 1.

Effects of thermal stratification on flow and heat transfer past a porous vertical stretching surface

2011 ◽  
Vol 48 (6) ◽  
pp. 915-921 ◽  
Author(s):  
Swati Mukhopadhyay ◽  
Iswar Chandra Mondal ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Heat Transfer ◽  
Thermal Stratification ◽  
Stretching Surface ◽  
Flow And Heat Transfer

Flow and Heat Transfer Characteristics of a Novel Heat Exchanger

2013 ◽  
Author(s):  
Haolin Ma ◽  
Alparslan Oztekin
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Transient Flow ◽  
Ansys Fluent ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Narrow Slot ◽  
Slot Size ◽  
Tube Type

Computational fluid dynamics and heat transfer simulations are conducted for a novel shell-tube type heat exchanger. The heat exchanger consists of tube with a narrow slot oriented in the streamwise direction. Numerical simulations are conducted for the Reynolds number of 1500. The 3D turbulent flow in the tube bank region is modeled by k-ε Reynolds stress averaging method by employing ANSYS FLUENT. 3-D transient flow and heat transfer simulations are conducted to determine the flow structure and temperature profiles in the wake of cylinders in the first row and other rows. The effects of the slot size and the orientation and the arrangement of the cylinder in different configuration will be examined. The slotted tube heat exchanger improved heat transfer by more than 27% compare to the traditional shell-tube heat exchanger without slots. Enhancement in heat transfer is even higher at higher values of Reynolds number.

In-Cylinder Heat Transfer Model for Diesel Engine Based on Improved Woschni Correlation

2014 ◽  
Vol 538 ◽  
pp. 175-178
Author(s):  
Xiao Ri Liu ◽  
Guo Xiang Li ◽  
Yu Ping Hu ◽  
Shu Zhan Bai ◽  
Kang Yao Deng
Keyword(s):  
Heat Transfer ◽  
Cfd Simulation ◽  
Transient Flow ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Three Dimension ◽  
Characteristic Parameters ◽  
Flow And Heat Transfer ◽  
Dimension Characteristic

Based on the Woschni correlation, a three dimensional in-cylinder heat transfer model is proposed, which develops Woschni correlation from zero dimension to three dimension. Characteristic parameters are proposed as transient flow and heat transfer parameters from in-cylinder CFD simulation, with further consideration of the influence of thermal conductivity, viscosity and Prandtl number. According to test data, the new correlation can be regressed. The new model costs little more calculation time, and it can satisfy the engineering demand.

Application of Domain Decomposition in Modelling Flow and Heat Transfer Problems

1996 ◽  
Vol 210 (6) ◽  
pp. 519-528 ◽  
Author(s):  
K Muralidhar ◽  
A Chatterjee ◽  
B V Nagabhushana Rao
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Domain Decomposition ◽  
Oil Recovery ◽  
Transient Flow ◽  
Two Dimensions ◽  
Processing Unit ◽  
Central Processing ◽  
Flow And Heat Transfer ◽  
Transfer Problems

The present work is concerned with the application of the domain decomposition technique for modelling transient flow and heat transfer problems. The solutions obtained within each subdomain are matched at the interfaces using Uzawa's algorithm. This algorithm has been originally developed in the context of steady heat conduction. The objective of the present study is to test and extend the algorithm to a wider class of problems. Examples considered are non-linear heat conduction in one and two dimensions, simulation of oil recovery from porous formations using water injection, movement of a plane thermal front and heat transfer from a cylinder placed in Darcian flow. The suitability of Uzawa's algorithm for interface treatment with up to nine subdomains has been studied. The method is found to converge to the full-domain solution in all cases considered. Besides this, results show that there are additional advantages which include the generation of small matrices and, in certain cases, a marginal reduction in CPU (central processing unit) time, even on sequential machines.

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