Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 K/D `((Dvp)/(mu))^0.8 . ((C_(p mu))/(K))^0.4` This is valid for the value of NRe equal to
Fouling factor for a heat exchanger is given by (where, U1 = heat transfer co-efficient of dirty surface U2 = heat transfer co-efficient of clean surface)
In case of surface condensers, a straight line is obtained on plotting `1/U` vs__________ on an ordinary graph paper.