//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