소구경 전열관 내의 열전달촉진 형상변화에 따른열전달 및 압력강하 특성에 관한 실험적 연구

Abstract

Friction and heat transfer coefficients were measured inside the corrugated tube using water as the working fluid. The test is performed for 16 tubes which outer diameter of tubes are 12.7mm. These specifications are 4 indentation depths and 4 indentation pitches, respectively. The range of the water velocity inside the tube is from 0.5 to 3.0m/s(8,500<Re< 34,000). If the indentation depth of the corrugated tube is increased, the friction and heat transfer coefficients are augmented. But, when the indentation pitch of the corrugated tube is increased, the Friction and heat transfer coefficients are decreased. Finally, The correlations for the friction and heat transfer coefficients were proposed with the indentation pitch and depth varying Reynolds number.