A long pipe carrying hot water loses heat to the ambient air. The heat loss was measured to be 480 W/m² at the outer surface of the pipe. The temperature of the hot water and the ambient air are 60°C and 20°C, respectively. The pipe has an inner diameter of 8 cm and outer diameter of 12 cm. The thermal conductivity of the pipe material is 1.4 W/m.K. If the convection coefficient of the hot water inside the pipe is 80 W/m².K, what is the convection coefficient of the ambient air? Assume steady and one-dimensional heat transfer. Neglect radiation.

A long pipe carrying hot water loses heat to the ambient air. The heat loss was measured to be 480 W/m² at the outer surface of the pipe. The temperature of the hot water and the ambient air are 60°C and 20°C, respectively. The pipe has an inner diameter of 8 cm and outer diameter of 12 cm. The thermal conductivity of the pipe material is 1.4 W/m.K. If the convection coefficient of the hot water inside the pipe is 80 W/m².K, what is the convection coefficient of the ambient air? Assume steady and one-dimensional heat transfer. Neglect radiation.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

A long pipe carrying hot water loses heat to the ambient air. The heat loss was measured to be
480 W/m² at the outer surface of the pipe. The temperature of the hot water and the ambient air are
60°C and 20°C, respectively. The pipe has an inner diameter of 8 cm and outer diameter of 12 cm. The
thermal conductivity of the pipe material is 1.4 W/m.K. If the convection coefficient of the hot water
inside the pipe is 80 W/m².K, what is the convection coefficient of the ambient air? Assume steady and
one-dimensional heat transfer. Neglect radiation.
к
21.2 W/m²K

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