Thermodynamics HW Solutions 744

Thermodynamics HW Solutions 744 - sigma=5.67E-8...

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Chapter 9 Natural Convection 9-47 "!PROBLEM 9-47" "GIVEN" height=0.28 "[m]" L=0.18 "[m]" w=0.18 "[m]" T_infinity=24 "[C]" T_w1=2 "[C]" epsilon=0.6 T_surr=T_infinity "time=3 [h], 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 beta=1/(T_film+273) T_film=1/2*(T_w_ave+T_infinity) T_w_ave=1/2*(T_w1+T_w2) 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)
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Unformatted text preview: sigma=5.67E-8 "[W/m^2-K^4], Stefan-Boltzmann constant" g=9.807 "[m/s^2], gravitational acceleration" "ANALYSIS" delta=height Ra=(g*beta*(T_infinity-T_w_ave)*delta^3)/nu^2*Pr Nusselt=0.59*Ra^0.25 h=k/delta*Nusselt A=2*(height*L+height*w+w*L) Q_dot=h*A*(T_infinity-T_w_ave)+epsilon*A*sigma*((T_surr+273)^4-(T_w_ave+273)^4) m_w=rho_w*V_w V_w=height*L*w Q=m_w*C_p_w*(T_w2-T_w1) Q_dot=Q/(time*Convert(h, s)) 9-45...
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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