Oil is flowing through a 75 mm id iron pipe at 1 m/s. the pipe has (7.5) mm thickness with thermal conductivity of 52 w/m.ºc. it is being heated by steam outside the pipe, and the steam-film coefficient may be taken as 11 kw/m2.ºc. at a particular point along the pipe, the oil is at (42)ºc, its density is 880 kg/m3, its viscosity is 2.1 cp, its thermal conductivity is 0.135 w/m.ºc, and its specific heat is 2.17 j/g.ºc.
what is the overall heat-transfer coefficient at this point based on the inside area of the pipe? if the steam temperature is (130)ºc, what is the heat flux at this point (kw/m2) based on the inside area of the pipe?
hi = w/m2.°c
ui = w/m2.°c
q/a = kw/m2