Thermodynamics HW Solutions 356

Thermodynamics HW Solutions 356 - "From Table 4-1...

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Chapter 4 Transient Heat Conduction 4-79 "!PROBLEM 4-79" "GIVEN" 2*L_1=0.04 "[m]" L_2=L_1 2*L_3=0.10 "[m]" "T_i=-20 [C], parameter to be varied" T_infinity=18 "[C]" h=12 "[W/m^2-C]" T_L1_L2_L3=0 "[C]" "PROPERTIES" k=2.22 "[W/m-C]" alpha=0.124E-7 "[m^2/s]" "ANALYSIS" "This block can physically be formed by the intersection of two infinite plane wall of thickness 2L=4 cm and an infinite plane wall of thickness 2L=10 cm" "For the two plane walls" Bi_w1=(h*L_1)/k "From Table 4-1 corresponding to this Bi number, we read" lambda_1_w1=0.3208 "w stands for wall" A_1_w1=1.0173 time*Convert(min, s)=tau_w1*L_1^2/alpha "For the third plane wall" Bi_w3=(h*L_3)/k
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Unformatted text preview: "From Table 4-1 corresponding to this Bi number, we read" lambda_1_w3=0.4951 A_1_w3=1.0408 time*Convert(min, s)=tau_w3*L_3^2/alpha theta_L_w1=A_1_w1*exp(-lambda_1_w1^2*tau_w1)*Cos(lambda_1_w1*L_1/L_1) "theta_L_w1=(T_L_w1-T_infinity)/(T_i-T_infinity)" theta_L_w3=A_1_w3*exp(-lambda_1_w3^2*tau_w3)*Cos(lambda_1_w3*L_3/L_3) "theta_L_w3=(T_L_w3-T_infinity)/(T_i-T_infinity)" (T_L1_L2_L3-T_infinity)/(T_i-T_infinity)=theta_L_w1^2*theta_L_w3 "corner temperature" T i [C] time [min] -26 1614 -24 1512 -22 1405 -20 1292 -18 1173 -16 1048 -14 914.9 -12 773.3 -10 621.9 -8 459.4 -6 283.7 -4 92.84 4-67...
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This note was uploaded on 01/19/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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