Conjugate heat transfer from a continuously moving material in a parallel channel flow for cooling in forming manufacturing processes

B. H. Kang, Y. Jaluria

Research output: Contribution to journalConference article

3 Scopus citations

Abstract

The conjugate mixed convection and conduction transport that arises due to the continuous movement of a heated material in a parallel channel flow has been numerically investigated. The problem studied is of interest in several manufacturing processes, ranging from crystal growing and continuous casting to extrusion, hot rolling, wire drawing and fiber drawing. The flow field and the temperature distributions in the solid, as well as in the flow, need to be studied in detail to provide inputs for design and for process control. A moving flat plate, or a sheet, is considered in this paper. A numerical study is carried out, assuming a two-dimensional, steady circumstance, with laminar flow in the fluid. The full elliptic equations are solved, employing finite difference techniques. The conjugate transport, resulting from the heat transfer mechanisms within the moving solid material and the convective heat transfer in the channel fluid flow, is investigated, the two mechanisms being coupled through the boundary conditions at the surface of the material. Numerical results are obtained for various values of the physical parameters such as the plate speed U3, the force flow velocity in the channel, U, and temperature T0 the material upstream of the cooling region. These are given in terms of the dimensionless variables, which are the Grashof number Gr, the Prandtl number Pr, the Peclet number Pe, the Reynolds number Re and the conductivity ratio, Kf/Ks, of the fluid to the material of the plate. Also, the effect of the geometry of the system is investigated. The results obtained indicate that the effect of thermal buoyancy on the downstream thermal and flow fields is more significant when a plate is moving vertically upward than when it is moving horizontally, as expected from the alignment of the buoyancy force with the motion in the former case. The buoyancy effect is found to be more important when the force flow velocity in the channel is small. A strong forced flow leads to a fairly uniform velocity distribution across much of the channel. It is also found that the rate of heat transfer from the heated plate to the channel flow strongly depends on the local velocity near the plate surface rather than the velocity level across the channel. Thus, the plate speed substantially affects the heat transfer rate. Several other important aspects of fundamental and applied interest are studied in this investigation.

Original languageEnglish (US)
Pages (from-to)25-35
Number of pages11
JournalAmerican Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
Volume146
Publication statusPublished - Dec 1 1990
EventWinter Annual Meeting of the American Society of Mechanical Engineers - Dallas, TX, USA
Duration: Nov 25 1990Nov 30 1990

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All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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