Thick fluids such as asphalt and waxes andthe pipes in which they flow are oftenheated in order to reduce the viscosity ofthe fluids and thus to reduce the pumpingcosts. Consider the flow of such a fluidthrough a 100-m-long pipe of outerdiameter 30 cm in calm ambient air at 0oC.The pipe is heated electrically, and athermostat keeps the outer surfacetemperature of the pipe constant at 250C.The emissivity of the outer surface of thepipe is 0.8, and the effective skytemperature is-300C. Determine thepower rating of the electric resistanceheater, in kW, that needs to be used. Also,determine the cost of electricity associatedwith heating the pipe during a 10-h periodunder the above conditions if the price ofelectricity is $0.09/kWh. Properties Theproperties of air at 1 atm and the filmtemperature of (Ts+To)/2 = (25+0)/2 =12.5°C are: k = 0.02458 W/m.oC, v =1.448x10-5 m2/s, Pr = 0.7330D=m

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Thick fluids such as asphalt and waxes am the pipes in which they flow are often heated in order to reduce the viscosity of the fluids and thus to reduce the pumping costs. Consider the flow of such a fluid

Thick fluids such as asphalt and waxes am the pipes in which they flow are often heated in order to reduce the viscosity of the fluids and thus to reduce the pumping costs. Consider the flow of such a fluid

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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