Prediction of friction factors and heat transfer coefficients for turbulent flow in corrugated tubes combined with twisted tape inserts. Part 2: heat transfer coefficients

摘要: Abstract A simple mathematical model following the suggestion of Smithberg and Landis has been created to predict heat transfer coefficients for case a fully developed turbulent flow in spirally corrugated tube combined with twisted tape insert. The can be predicted from effects axial tangential boundary layer flows coupled an additional “vortex mixing” effect near wall through solution corresponding momentun energy equations. “wall roughness” simultaneously on velocity, secondary fluid motion resulting swirl mixing. reflects influence thermal resistances helicoidal core flow, twisting viscous sublayer wall. calculated have compared 544 experimental points obtained 57 tubes tested. Four hundred thirty-eight (80.5%) relative difference less than ±15% 106 (19.5%) between ±(15–20)%.