传热学期末模拟试题.pdf

本套试题版权归热能1101 班所有——热能1101 班学委倾情奉献 传热学期末模拟试题 1. Please answer these short-answer questions. (1)Please give the heat conduction differential equation in Rectangular Coordinates and write down the physical significance of every term.(BTW, what about in Cyl. and Sph. Coordinates?) (2)What are the expression of these criterion numeral (准则数) , and what about their physical significance? Bi Nu Fo Pr Gr (3)Give a brief introduction of Pooling Boiling.(In figure) 1 本套试题版权归热能1101 班所有——热能1101 班学委倾情奉献 (4)What does the effective conductivity of an enclosure represent? How is the ratio of the effective conductivity to thermal conductivity related to the Nusselt number? 2.Fill in the blanks. (1)One face of a copper plate 3cm thick is maintained at 400℃, and the other face is maintained at 100 ℃，so the heat is transferred through the plate is _____W. (Apply the table in the text book) (2)Two infinite black plates at 800 ℃ and 300℃ exchanger heat by radiation, and the heat transfer per unit area is ______W. (3)Logarithmic Mean Temperature Difference is _______________. (4)Look the figure on the right, in which T ,T ,L ,L ,L ,k ,k ,k , ∞1 ∞2 1 2 3 1 2 3 h ,h is known,so 1 4 Ts3=______________. (5) The physical significance of Fin Efficiency is _________________________________________________. (6)The gray surface’s properties are independent of _________. (7)The mechanisms(途径) of heat transfer are _______ , ________ and _________ . (8) Radiation heat exchange between surfaces depends on the orientation of the surfaces relative to each other, which is accounted for by the __________. 2 本套试题版权归热能1101 班所有——热能1101 班学委倾情奉献 3. Calculation que