Model Exchange

Various Mode Heat Transfer

AJ Baker, University of Tennessee, Knoxville

Consider an array of heated tubes submerged in a vessel with fluid flowing past them. Neglecting end effects, the flowfield can be assumed 2-D in planes with normals parallel to the tube axes. Further, for modest fluid onset velocity, a steady state solution can be sought.

This example comes from the textbook "The Computational Engineering Sciences" by A.J. Baker.

Objectives of this problem:

1. Become familiar with the COMSOL Multiphysics environment and its graphical user interface.
2. Appreciate the role of the Reynolds and Nusselt non-dimensional groups on heat transfer characterization.
3. Generate simulations for natural, mixed and forced convection heat transfer by adjusting the Reynolds number Re.
4. Perform a mesh refinement study for each class of heat exchange, solution-adapted if necessary, hence estimate the mesh required for each solution to be engineering accurate.
5. Detail the generated heat transfer mode differences graphically and quantitatively and report the results.

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User Comments

James Freels
Aug 11, 2009 at 8:42pm UTC

The model file provided is set up for a time-dependent (transient) solution. I attempted to solve this problem in the time-dependent mode, but was not successful. I believe the author intended to solve this problem as a steady-state problem which, indeed, does converge as expected. The default adaptive-mesh solution also works fine on this problem yielding a dispersion-free solution. The variation in Re also produced the expected results. Some interesting variations I tried included to convert the problem from dimensionless to SI units (easily done), using PARDISO solver, and the use of artificial dissipation under the stabilization menu. This is a very interesting problem; particularly the inability to obtain a transient solution here.

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