• Title/Summary/Keyword: Spirally Indented Tube

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Characteristics of Heat Transfer and Pressure Drop for Spirally Indented Tubes with Wire Coil Inserts (와이어 코일이 삽입된 나선형 내면가공관의 열전달 및 압력강하 특성)

  • Choi, In-Su;Park, Byung-Duck;Nam, Sang-Chul
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.4
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    • pp.395-401
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    • 2001
  • The characteristics of heat transfer and pressure drop through tubes has been investigated experimentally for a compound heat transfer enhancement. The test tubes were spirally indented tubes with wire coil inserts which had a various combinations of pitch and helix angles. Pure water was used as working fluids for the experiments, Heat transfer coefficients and friction factors of the test tubes were evaluated from the values of measured temperatures, flow rates and pressure drops. An performance evaluation was performed to find an optimal combination of spirally indented tubes with wire coil inserts. When the helix angle of wire coil insert are $71^{\circ}-72^{\circ}$, the best heat transfer enhancement was shown. The friction factor was 9 - 13 times higher than those in smooth tubes, and the heat transfer was enhanced a maximum of 500%.

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Investigation on Characteristics of Pressure Drop and Heat Transfer in the Spirally Indented Tubes (스파이럴리 인덴티드 전열관 내부에서의 압력 강하 및 전열 특성에 관한 고찰)

  • Kim, Do-Hyoung;Kim, Ik-Saeng;Kim, Kyun-Seok;Yoo, Byoung-Hoon;Kim, Chun-Dong
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.440-446
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    • 2001
  • The pressure drop and heat transfer of the spirally indented tubes were measured and analyzed. Eight sample tubes of indentation depth 0.4, 0.7mm and indentation pitch 10, 14, 20, 26mm were used in this experimental tests. And all the tubes have same outer diameter of 16mm, and same indentation start number of I. Air was used as the internal fluid from 10000 to 50000 for Reynolds Number. The friction factors and heat transfer coefficients have increased when indentation depths increase and indentation pitches decrease. Finally, the correlations were made between the effect of the tube geometry and characteristics of tubes for the pressure drop and heat transfer.

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