Hi Omar,

depending on the radius of the parabolic dish, you might be able to simplify the problem and consider it a plane assuming air flow parallel to the surface. Thus a mean Nusselt number can be calculated using the Colburn analogy. See e.g. James R. Welty et al. (2007). Fundamentals of Momentum, Heat and Mass transfer (5th edition). John Wiley and Sons. ISBN 978-0470128688

Best regards,

Christoph

Thank you Christoph, this is exactly what I assumed.

However, I was hoping to find a more refined correlation for parabolic surfaces.

Dear Omar

I think I have seen the heat transfer coefficient for a parabolic through system being determined in this publication from NREL

http://www.nrel.gov/csp/troughnet/pdfs/34169.pdf

In general this is a good reference guide also.

FC