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Diffstat (limited to '2510/CH17/EX17.15/Ex17_15.sce')
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1 files changed, 38 insertions, 0 deletions
diff --git a/2510/CH17/EX17.15/Ex17_15.sce b/2510/CH17/EX17.15/Ex17_15.sce new file mode 100755 index 000000000..8a282671c --- /dev/null +++ b/2510/CH17/EX17.15/Ex17_15.sce @@ -0,0 +1,38 @@ +//Variable declaration: +Do = 50/10**3 //Outside diameter of tube (m) +t = 4/10**3 //Thickness of fin (m) +T = 20 //Fluid temperature ( C) +Tb = 200 //Surface temperature ( C) +h = 40 //Heat transfer coefficient (W/m^2.K) +k = 240 //Thermal conductivity of fin (W/m.K) +l = 15/10**3 //Length of fin (m) + +//Calculation: +ro = Do/2 //Radius of tube (m) +rf = ro+l //Outside radius of fin (m) +Ab = 2*%pi*ro*t //Area of the base of the fin (m^2) +Te = Tb-T //Excess temperature at the base of the fin (K) +Q1 = h*Ab*Te //Total heat transfer rate without the fin (W) +Bi = h*(t/2)/k //Biot number +L = rf-ro //Fin height (m) +rc = rf+t/2 //Corrected radius (m) +Lc = L+t/2 //Corrected height (m) +Ap = Lc*t //Profile area (m^2) +Af = 2*%pi*(rc**2-ro**2) //Fin surface area (m^2) +Qm = h*Af*Te //Maximum fin heat transfer rate (W) +A = sqrt(Lc**3*h/(k*Ap)) //Abscissa of fin efficiency +C = rf/ro //Curve parameter of fin efficiency +//From figure 17.4: +nf = 0.97 //Fin efficiency +Qf = nf*Qm //Fin heat transfer rate (W) +R = Te/Qf //Fin resistance (K/W) +E = Qf/Q1 //Fin effectiveness + +//Result: +printf("The fin efficiency is : %.0f %%",nf*100) +printf("The fin thermal resistance is : %.1f C/W.",R) +printf("The fin effectiveness is : %.2f .",E) +printf("The maximum heat transfer rate from a single fin is : %.2f W .",Qm) +if E>2 then + printf("Since Ef = FCP>2, the use of the fin is justified.") +end |