文档介绍：Convective Heat Transfer
Final Exam A 卷
Note: Two-hour closed book final examination. One crib sheet (A4, both sides) is permitted.
Calculator is allowed. There are 6 problems and 100 points on the exam. Point values for each
question and part are listed. State clearly and justify all assumptions made and label all sketches
and thermal circuits clearly. Your answers must be correct to 3 significant figures and have the
appropriate units. Allocate your time wisely and do not spend disproportionate time on any single
problem. Take a deep breath and relax. Good luck!
1. [20 points] A flat plate of width w=1 m and length L= 1 m is maintained at a uniform surface
temperature, T . The plate is exposed to a fluid stream at u =10 m/s and T =300 K and it has
s ∞∞
been found that the total heat transfer rate from the plate (top surface only) is 1000 W
( k = / m ⋅ K , kinematic viscosity ν= thermal diffusivity α= 1×10−5 m 2 / s ).
(a) What is the surface temperature Ts?
(b) Experiments show that the temperature profile (along the direction normal to the surface) at
the trailing edge (x=1m) can be approximated as T(y) = a + bexp(− cy) , where c=1876 m-1.
Estimate (or explain how to calculate) the magnitude of constant b [K].
2. [20 points] Two identical circular pipes of diameter m and length 10 m are connected in