Annular fin
The following commands are used to evaluate the thermal resistance of an annular fin:
k=30; h=1000; ri=.03; ro=.045; t=.003; Tb=100; Tinf=20;
% 'c' denotes the convective tip condition ('a' is for adiabatic)
[Rfin Bi] = AnnFinApprox(h,k,ri,ro,t,'c')
Rfin = 0.36290
Bi = 0.10000
Qfin = (Tb-Tinf)/Rfin % heat transfer rate in watts through fin
Qfin = 220.45