Forced convection heat transfer of nitrogen at supercritical pressure

Tatsumoto, Hideki; Shirai, Yasuyuki*; Hata, Koichi*; Kato, Takashi; Shiotsu, Masahiro*

Forced flow heat transfers of supercritical nitrogen in a horizontal tube was measured for wide range of inlet temperature and flow velocity conditions. The heat transfer coefficients agreed well with those predicted by Dittus-Boelter correlation for the surface temperature lower than pseudo-critical temperature, Tc'. When the surface temperature exceeds Tc', they become lower than those by the correlation. The heat transfer coefficients at a certain wall temperature became lower with decrease in Reynolds number (Re) down to about 8000. Further decrease in Re did not affect the heat transfer coefficients. The lowest limits agreed with those obtained for natural convection.