Heatline Based Thermal Behaviour during Cooling of a Hot Moving Steel Plate Using Single Jet

2014 ◽  
Vol 592-594 ◽  
pp. 1622-1626
Author(s):  
Suman Samanta ◽  
Saikat Mukherjee ◽  
Mrinmoy Dhar ◽  
Shambhunath Barman ◽  
Nilkanta Barman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Steel Plate ◽  
Numerical Code ◽  
Computational Domain ◽  
Algebraic Equations ◽  
Transfer Region ◽  
Linear Algebraic Equations ◽  
Visualization Process ◽  
Single Jet ◽  
Volume Method

The article deals with visualization of heatlines and isotherms during cooling of a hot moving steel plate numerically. The cooling of the plate is assumed using single spray-water jet. The visualization process is carried out by forming and discretizing the governing energy equation based on finite volume method. The linear algebraic equations are solved by tri-diagonal matrix algorithm (TDMA). Accordingly, a numerical code is developed on FORTRAN platform. In the computational domain, a suitable heat transfer region for cooling is identified analyzing the heatline distribution in the domain and depends on the process parameters. Accordingly a parametric study is performed and reveals that effective heat transfer region increases with increasing jet velocity and cooling methods, and decreases with increasing plate velocity.

A Thermo-Mechanical Model for a Counterflow Biomass Gasifier

2014 ◽  
Vol 354 ◽  
pp. 227-235
Author(s):  
Marcelo J.S. de Lemos
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Control Volume ◽  
Simple Algorithm ◽  
Thermal Capacity ◽  
Macroscopic Model ◽  
Algebraic Equations ◽  
Medium Permeability ◽  
Mechanical Approach ◽  
Volume Method

This article presents a thermo-mechanical approach to investigate heat transfer between solid and fluid phases in a model gasifier. A two-temperature equation approach is applied in addition to a macroscopic model for laminar flow through a porous moving bed. Transport equations are discretized using the control-volume method and the system of algebraic equations is relaxed via the SIMPLE algorithm. The effects on inter-phase heat transfer due to variation of medium permeability, thermal conductivity and thermal capacity are analyzed. Results indicate that for smaller medium permeabilities, as well as for higher solid-to-fluid thermal capacity and thermal conductivity ratios, enhancement of heat transfer between phases is observed.

Pressure Drop Characteristics of Parallel-Plate Channel Flow With Porous Obstructions at Both Walls

2003 ◽  
Author(s):  
Marcelo J. S. de Lemos ◽  
Luzia A. Tofaneli
Keyword(s):  
Numerical Solutions ◽  
Control Volume ◽  
Computational Domain ◽  
Algebraic Equations ◽  
Clear Fluid ◽  
Simple Method ◽  
Periodic Cell ◽  
Porosity And Permeability ◽  
Volume Method ◽  
Turbulence Transport

In this work, numerical solutions are presented for turbulent flow in a channel containing fins made with porous material. The condition of spatially periodic cell is applied longitudinally along the channel. A macroscopic tow-equation turbulence model is employed in both the porous region and the clear fluid. The equations of momentum, mass continuity and turbulence transport equations are written for an elementary representative volume yielding a set of equations valid for the entire computational domain. These equations are discretized using the control volume method and the resulting systems of algebraic equations is relaxed with the SIMPLE method. Results are presented for the velocity field as a function of Reynolds number, porosity and permeability of the fins.

Numerical Solutions of Nano/Microphenomena Coupled With Macroscopic Process of Heat Transfer and Fluid Flow: A Brief Review

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Ya-Ling He ◽  
Wen-Quan Tao
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Solutions ◽  
Dynamics Simulation ◽  
Computational Time ◽  
Computational Domain ◽  
Flow Problems ◽  
Coupling Algorithms ◽  
Volume Method ◽  
Boltzmann Method

In this paper, numerical simulation approaches for multiscale process of heat transfer and fluid flow are briefly reviewed, and the existing coupling algorithms are summarized. These molecular dynamics simulation (MDS)–finite volume method (FVM), MD–lattice Boltzmann method (LBM), and direct simulation of Monte Carlo method (DSMC)–FVM. The available reconstruction operators for LBM–FVM coupling are introduced. Four multiscale examples for fluid flow and heat transfer are presented by using these coupled methods. It is shown that by coupled method different resolution requirements in the computational domain can be satisfied successfully while computational time can be significantly saved. Further research needs for the study of multiscale heat transfer and fluid flow problems are proposed.

scholarly journals Organization of parallel-pipeline calculations for modeling the pollutant distribution process in a reservoir

2021 ◽  
Vol 2131 (3) ◽  
pp. 032050
Author(s):  
V N Litvinov ◽  
N N Gracheva ◽  
A A Filina ◽  
A V Nikitina
Keyword(s):  
Water Pollution ◽  
Toxic Substances ◽  
Computational Domain ◽  
Algebraic Equations ◽  
Pollution Transport ◽  
Waste Products ◽  
Multiprocessor Computer ◽  
Emergency Situations ◽  
Parallel Pipeline ◽  
Linear Algebraic Equations

Abstract One of the most acute problems for today is the water pollution. For rapid decision in emergency situations, it is necessary to develop effective software and algorithmic tools that allow us to make accurate forecasts of the environmental situation changing of coastal systems. Water pollution of the Azov and Black Seas by storm drains and human waste products leads to an increase of toxic substances concentrations that significantly exceed the maximum permissible values. The pollution transport problem is solved on the basis of the Navier-Stokes and the diffusion-convection-reaction equations. As a result of discretization of the continuous problem of transport of pollutants using the finite-difference approach for a rectangular grid, we obtain a system of linear algebraic equations (SLAE) of large dimension, which require significant time costs. To increase the efficiency of calculations (to reduce the time) on a multiprocessor computer system (MCS), there is a need to develop effective parallel algorithms for solving SLAE. The decomposition method for a two-dimensional computational domain is proposed in this paper, which allows organizing a parallel-pipeline process of calculations as follows: at each stage of calculations, each processor core simultaneously processes fragments of the computational domain that are offset from each other. This process is described in the form of a graph, in which each node corresponds to fragments of the computational domain, and the edges – a sign of the adjacency of fragments.

Forced Response of Bladed Disks in Cyclic Symmetry With Underplatform Dampers

2006 ◽  
Author(s):  
Stefano Zucca ◽  
Juan Borrajo ◽  
Muzio M. Gola
Keyword(s):  
Contact Stiffness ◽  
Harmonic Balance Method ◽  
Rigid Bodies ◽  
Forced Response ◽  
Numerical Code ◽  
Algebraic Equations ◽  
Bladed Disks ◽  
Disk Model ◽  
Normal Contact ◽  
Linear Algebraic Equations

In this paper a methodology for forced response calculation of bladed disks with underplatform dampers is described. The FE disk model, supposed to be cyclically symmetric, is reduced by means of Component Mode Synthesis and then DOFs lying at interfaces are further reduced by means of interface modes. Underplatform dampers are modeled as rigid bodies translating both in the radial and in the tangential direction of the engine. Contacts between blade platforms and damper are simulated by means of contact elements characterized by both tangential and normal contact stiffness, allowing partial separation of contact surfaces. Differential equilibrium equations are turned in non-linear algebraic equations by means of the Harmonic Balance Method (HBM). The methodology is implemented in a numerical code for forced response calculation of frictionally damped bladed disks. Numerical calculations are performed to evaluate the effectiveness of both the reduced order model and the underplatform model in simulating the dynamic behavior of bladed disks in presence of underplatform dampers.

scholarly journals Numerical simulation of the non-regular mode of cooling a high-temperature metal billet by the flow of a gas-liquid medium

2018 ◽  
Vol 224 ◽  
pp. 04003
Author(s):  
Sergey Makarov ◽  
Vyacheslav Dement’yev ◽  
Tat’yana Makhneva ◽  
Elena Makarova
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
High Temperature ◽  
Liquid Medium ◽  
Liquid Flow ◽  
Control Volume ◽  
Algebraic Equations ◽  
Linear Algebraic Equations ◽  
Gas Liquid Flow ◽  
Regular Mode

A mathematical model of heat transfer at cooling a high-temperature metal billet from structural steel by the flow of a gas-liquid medium in a vertical circular channel is presented. The model has been built with the use of the continuum mechanics approaches and the theory of heat-mass transfer. The non-regular mode of cooling is considered. The results of the numerical parametric investigations of the heat transfer at cooling a metal billet are obtained for a standard regime of thermomechanical strengthening on the basis of the mathematical model of conjugate heat transfer in a two-dimensional nonstationary formulation accounting for the symmetry of the cooling medium flow relative to the longitudinal axis of a cylinder. The control volume approach is used for solving the system of differential equations. The flow field parameters are computed by an algorithm SIMPLE. For the iterative solution of the systems of linear algebraic equations the Gauss-Seidel method with under-relaxation is used. Taking into account evaporation in the liquid, the intensity of the change of the rate of cooling the material of the metal cylindrical billet by the laminar gas-liquid flow is analyzed depending on the time of cooling and the velocity of the gas-liquid flow.

Numerical simulation of magnetohydrodynamic micropolar fluid flow and heat transfer in a channel with shrinking walls

2014 ◽  
Vol 92 (9) ◽  
pp. 987-996 ◽  
Author(s):  
Kashif Ali ◽  
Muhammad Ashraf ◽  
Nimra Jameel
Keyword(s):  
Heat Transfer ◽  
Micropolar Fluid ◽  
Thermal Control ◽  
Computational Procedure ◽  
Physical Parameters ◽  
Algebraic Equations ◽  
Iteration Parameter ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Linear Algebraic Equations

We numerically study the steady hydromagnetic (magnetohydrodynamic) flow and heat transfer characteristics of a viscous incompressible electrically conducting micropolar fluid in a channel with shrinking walls. Unlike the classical shooting methodology, two distinct numerical techniques are employed to solve the transformed self-similar nonlinear ordinary differential equations (ODEs). One is the combination of a direct and an iterative method (successive over-relaxation with optimal relaxation parameter) for solving the sparse system of linear algebraic equations arising from the finite difference discretization of the linearised ODEs. For the second one, a pseudotransient method is used where time plays the role of an iteration parameter until the steady state is reached. The two approaches may be easily extended to other geometries (for example, sheets, disks, and cylinders) with possible wall conditions like slip, stretching, rotation, suction, and injection. Effects of some physical parameters on the flow and heat transfer are discussed and presented through tables and graphs. Detailed description of the computational procedure and the results of the study may be beneficial for the researchers in the flow and thermal control of polymeric processing.

3D natural convection on a horizontal and vertical thermally active plate in a closed cubical cavity

2016 ◽  
Vol 26 (8) ◽  
pp. 2528-2542 ◽  
Author(s):  
Abimanyu Purusothaman ◽  
Abderrahmane Baïri ◽  
Nagarajan Nithyadevi
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Convection Heat Transfer ◽  
Numerical Code ◽  
Heated Plate ◽  
Algebraic Equations ◽  
Content Type ◽  
Cubical Cavity

Purpose The purpose of this paper is to examine numerically the natural convection heat transfer in a cubical cavity induced by a thermally active plate. Effects of the plate size and its orientation with respect to the gravity vector on the convective heat transfer and the flow structures inside the cavity are studied and highlighted. Design/methodology/approach The numerical code is based on the finite volume method with semi-implicit method for pressure-linked equation algorithm. The convective and diffusive terms in momentum equations are handled by adopting the power law scheme. Finally, the discretized sets of algebraic equations are solved by the line-by-line tri-diagonal matrix algorithm. Findings The results show that plate orientation and size plays a significant role on heat transfer. Also, the heat transfer rate is an increasing function of Rayleigh number for both orientations of the heated plate. Depending on the thermal management of the plate and its application (as in electronics), the heat transfer rate is maximized or minimized by selecting appropriate parameters. Research limitations/implications The flow is assumed to be 3D, time-dependent, laminar and incompressible with negligible viscous dissipation and radiation. The fluid properties are assumed to be constant, except for the density in the buoyancy term that follows the Boussinesq approximation. Originality/value The present work will give some additional knowledge in designing sealed cavities encountered in some engineering applications as in aeronautics, automobile, metallurgy or electronics.

scholarly journals Calculation of heat transfer in nanoscale heterostructures

2019 ◽  
Vol 21 (3) ◽  
pp. 175-181
Author(s):  
K. K. Abgarian ◽  
I. S. Kolbin
Keyword(s):  
Heat Transfer ◽  
Heat Dissipation ◽  
Parallel Implementation ◽  
Numerical Models ◽  
Hybrid Approach ◽  
Mean Free Path ◽  
Algebraic Equations ◽  
Mesh Free ◽  
Linear Algebraic Equations ◽  
Spatial Approximation

Abstract. The article discusses the calculation of the temperature regime in nanoscale AlAs/GaAs binary heterostructures. When modeling heat transfer in nanocomposites, it is important to take into account that heat dissipation in multilayer structures with layer sizes of the order of the mean free path of energy carriers (phonons and electrons) occurs not at the lattice, but at the layer boundaries (interfaces). In this regard, the use of classical numerical models based on the Fourier law is limited, because it gives significant errors. To obtain more accurate results, we used a model in which the heat distribution was assumed to be constant inside the layer, while the temperature was stepwise changed at the interfaces of the layers. A hybrid approach was used for the calculation: a finite−difference method with an implicit scheme for time approximation and a mesh−free model based on a set of radial basis functions for spatial approximation. The calculation of the parameters of the bases was carried out through the solution of the systems of linear algebraic equations. In this case, only weights of neuroelements were selected, and the centers and «widths» were fixed. As an approximator, a set of frequently used basic functions was considered. To increase the speed of calculations, the algorithm was parallelized. Calculation times were measured to estimate the performance gains using the parallel implementation of the method.

Improving Profile Cooling through Modeling

2006 ◽  
Vol 514-516 ◽  
pp. 1429-1433 ◽  
Author(s):  
João M. Nóbrega ◽  
Olga S. Carneiro
Keyword(s):  
Heat Transfer ◽  
Analytical Solution ◽  
Numerical Code ◽  
Cooling Efficiency ◽  
Cooling Stage ◽  
Average Temperature ◽  
Global Cooling ◽  
Lower Temperature ◽  
The Individual ◽  
Volume Method

A 3D numerical code, based on the finite volume method, able to model the cooling stage of an extrusion line is presented and validated. For this purpose, an analytical solution of a simple heat transfer multi domain problem was developed, the result obtained being compared with the predictions given by the numerical code. A prior study performed with the above mentioned code showed that in general when a reduction of the profile average temperature is imparted, lower temperature homogeneity is also obtained, being the only exceptions the reduction of the extrusion velocity and splitting the calibrator into several units, separated by annealing zones. Therefore, the only way to improve the cooling efficiency without compromising the production rate is to divide the total cooling length into several independent units. In this work that investigation is further extended to study the influence of the individual cooling units and annealing zones lengths distributions on the global cooling efficiency.

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