The effects of curvature and the resulting centrifugal instabilities on local heat transfer distributions are studied in a curved channel with a rectangular cross section and a 40 to 1 aspect ratio at Dean numbers from 100 to 278. The experimental conditions are identified for which forced convection with weak buoyancy, and forced convection with strong buoyancy are present. With weak buoyancy effects present (Re2/Gr > 50 x 10-6 ) a new method is developed to deduce forced convection Nusselt numbers without the influence of natural convection. Resulting data provide information on the influence of Dean vortex pair and their secondary flows. For a Dean number of 275, Nusselt numbers measured on the concave surface are higher than the ones on the convex surface through out the curved portion, for X/D from 130 to 230, where X is the distance from the start of the heated section, and D is the width of the channel. For Dean numbers from 175 to 250, Nusselt numbers are higher on the concave surface than on the convex surface for X/D from 160 to 230, such that differences increase with Dean number.

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http://archive.org/details/astudyofnusseltn1094524054

Lieutenant, United States Navy