CB_w      150[mm]        Circuit board width
CB_l      150[mm]        Circuit board length
CB_t      3[mm]          Circuit board thickness
IC1_w     50[mm]         IC 1 width
IC1_l     50[mm]         IC 1 length
IC1_t     3[mm]          IC 1 thickness
IC2_w     15[mm]         ICs 2 width
IC2_l     20[mm]         ICs 2 length
IC2_t     3[mm]          ICs 2 thickness
IC3_w     15[mm]         ICs 3 width
IC3_l     40[mm]         ICs 3 length
IC3_t     3[mm]          IC2 3 thickness
P1        20[W]          Power dissipated by IC 1
P2        1[W]           Power dissipated by ICs 2
P3        2[W]           Power dissipated by ICs 3
htc       20[W/(m^2*K)]  Heat transfer coefficient
T0        273.15[K]      Air flow temperature
e_fins    0.3[mm]        Fins thickness
i_radius  5[mm]          Inner radius
o_radius  25[mm]         Outer radius
air_sp    3[mm]          Air spacing between sink fins
n_fins    10             Number of fins
t_h       air_sp*n_fins  Heat sink tube height