Thermodynamics HW Solutions 667

# Thermodynamics HW Solutions 667 - D_h=(4*A_c)/p...

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Chapter 8 Internal Forced Convection "GIVEN" L=7 "[m]" width=0.15 "[m]" height=0.20 "[m]" T_i=50 "[C]" "Vel=7 [m/s], parameter to be varied" T_s=10 "[C]" "PROPERTIES" Fluid\$='air' C_p=CP(Fluid\$, T=T_ave)*Convert(kJ/kg-C, J/kg-C) k=Conductivity(Fluid\$, T=T_ave) Pr=Prandtl(Fluid\$, T=T_ave) rho=Density(Fluid\$, T=T_ave, P=101.3) mu=Viscosity(Fluid\$, T=T_ave) nu=mu/rho T_ave=1/2*(T_i+T_e) "ANALYSIS" "(a)" A_c=width*height p=2*(width+height)
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Unformatted text preview: D_h=(4*A_c)/p Re=(Vel*D_h)/nu "The flow is turbulent" L_t=10*D_h "The entry length is much shorter than the total length of the duct." Nusselt=0.023*Re^0.8*Pr^0.3 h=k/D_h*Nusselt A=2*L*(width+height) m_dot=rho*Vel*A_c T_e=T_s-(T_s-T_i)*exp((-h*A)/(m_dot*C_p)) "(b)" DELTAT_ln=(T_e-T_i)/ln((T_s-T_e)/(T_s-T_i)) Q_dot=h*A*DELTAT_ln "(c)" f=0.184*Re^(-0.2) DELTAP=f*L/D_h*(rho*Vel^2)/2 W_dot_pump=(m_dot*DELTAP)/rho 8-29...
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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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