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# 2019 NCEES T&F Problem #10

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Posted (edited)

Could someone please explain why the solution just added the radiation and convection heat transfer coefficients instead of treating them like resistors in parallel?

Edited by BuffaloWings
Wrong year
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Sorry this is from the 2011 Exam (not 2001)

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Posted (edited)
4 hours ago, BuffaloWings said:

Could someone please explain why the solution just added the radiation and convection heat transfer coefficients instead of treating them like resistors in parallel?

I have the 2011 NCEES Practice Exam, Thermal and Fluid Systems. ISBN 978-1-932613-61-2

There does not seem to be a problem #10. There's a #110 in the AM section and a #510 in the PM section, but none of those seem to match what you're describing.

Can you provide a screenshot of the question and answer?

Edited by Dr. Barber
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Sorry it’s actually 2019

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They did treat it as resistances in parallel.

For parallel you find the total resistance as 1/R_total = 1/R_conv + 1/R_rad hence 1/R_total = (h_conv + h_rad)*A

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Thank you. I worked it out again and realized my mistake.

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