Thermodynamics HW Solutions 590

Thermodynamics HW Solutions 590 - Re=(Vel*Convert(km/h,...

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Chapter 7 External Forced Convection 7-59 "!PROBLEM 7-59" "GIVEN" D=0.50 "[m]" L=0.95 "[m]" T_w1=80 "[C]" T_infinity=18 "[C]" Vel=40 "[km/h]" "time=45 [min], parameter to be varied" "PROPERTIES" Fluid$='air' k=Conductivity(Fluid$, T=T_film) Pr=Prandtl(Fluid$, T=T_film) rho=Density(Fluid$, T=T_film, P=101.3) mu=Viscosity(Fluid$, T=T_film) nu=mu/rho T_film=1/2*(T_w_ave+T_infinity) rho_w=Density(water, T=T_w_ave, P=101.3) C_p_w=CP(Water, T=T_w_ave, P=101.3)*Convert(kJ/kg-C, J/kg-C) T_w_ave=1/2*(T_w1+T_w2) "ANALYSIS"
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Unformatted text preview: Re=(Vel*Convert(km/h, m/s)*D)/nu Nusselt=0.3+(0.62*Re^0.5*Pr^(1/3))/(1+(0.4/Pr)^(2/3))^0.25*(1+(Re/282000)^(5/8))^(4/5) h=k/D*Nusselt A=pi*D*L+2*pi*D^2/4 Q_dot=h*A*(T_w_ave-T_infinity) m_w=rho_w*V_w V_w=pi*D^2/4*L Q=m_w*C_p_w*(T_w1-T_w2) Q_dot=Q/(time*Convert(min, s)) time [min] T w2 [C] 30 73.06 45 69.86 60 66.83 75 63.96 90 61.23 105 58.63 120 56.16 135 53.8 150 51.54 165 49.39 180 47.33 195 45.36 210 43.47 225 41.65 240 39.91 255 38.24 270 36.63 285 35.09 300 33.6 7-45...
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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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