Thermodynamics HW Solutions 639

# Thermodynamics HW Solutions 639 - Chapter 8 Internal Forced...

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Unformatted text preview: Chapter 8 Internal Forced Convection Chapter 8 INTERNAL FORCED CONVECTION General Flow Analysis 8-1C Liquids are usually transported in circular pipes because pipes with a circular cross-section can withstand large pressure differences between the inside and the outside without undergoing any distortion. 8-2C Reynolds number for flow in a circular tube of diameter D is expressed as υ D m V = Re where ρ μ υ ρπ π ρ ρ = = = = ∞ and 4 ) 4 / ( 2 2 D m D m A m c & & & V Substituting, μ π ρ μ ρπ υ D m D D m D m & & 4 ) / ( 4 Re 2 = = = V 8-3C Engine oil requires a larger pump because of its much larger density. 8-4C The generally accepted value of the Reynolds number above which the flow in a smooth pipe is turbulent is 4000. 8-5C For flow through non-circular tubes, the Reynolds number as well as the Nusselt number and the friction factor are based on the hydraulic diameter D h defined as p A D c h 4 = where A c is the cross- sectional area of the tube and p is its perimeter. The hydraulic diameter is defined such that it reduces to is its perimeter....
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## This note was uploaded on 01/22/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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