ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Internal Symmetries, Fundamental Invariants, and Convective Heat Transfer from a Rotating Disk
Abstract
The convective heat transfer from a rotating disc subjected to an outer stream of air depends at least on three
characteristic parameters, namely crossflow, rotational Reynolds numbers and angle of incidence. These three
parameters determine the several flow and heat transfer regimes. The special case of a disc placed perpendicular
to the crossflow can be described mathematically in terms of a similarity solution using a combined single
Reynolds number, but more general configurations can only be described by using complex three-dimensional
flow patterns with flow separation. A detailed experimental study of the convective heat transfer from an
electrically heated rotating disc in a wind tunnel was conducted for a large range of crossflow and rotational
Reynolds numbers and angle of incidence. We found that the flow and heat transfer regimes were governed by a
reduced number of characteristic parameters for specific ranges of Reynolds numbers and angle of incidence.
The results also demonstrated the existence of non-continuous transitions between different flow regimes for
specific values of the angle of incidence. This unexpected behavior is explained within the framework of
symmetry and fundamental invariants. Based on the experimental data and theoretical considerations, Landau
and Landau-de Gennes models show great potential for formulating suitable convective heat transfer correlations
for rotating discs subjected to crossflows.