Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Rotation Speed on Heat Transfer and Flow in a Coolant Passage with Turning Region ( I ) - Cross Ribbed Duct -

곡관부를 가지는 내부 냉각유로에서 회전수 변화에 따른 열전달 및 유동 특성 ( I ) - 엇갈린 요철배열 덕트 -

  • 김경민 (연세대학교 대학원 기계공학과) ;
  • 김윤영 (연세대학교 대학원 기계공학과) ;
  • 이동호 (연세대학교 기계공학과) ;
  • 조형희 (연세대학교 기계공학과)
  • Published : 2005.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

The present study investigates heat/mass transfer and flow characteristics in a ribbed rotating passage with turning region. The duct has an aspect ratio (W/H) of 0.5 and a hydraulic diameter ($D_h$) of 26.67 mm. Rib turbulators are attached in the cross arrangement on the leading and trailing surfaces of the passage. The ribs have a rectangular cross section of $2\;mm\;(e){\times}\;mm\;(w)$ and an attack angle of $70^{\circ}$. The pitch-to-rib height ratio (p/e) is 7.5, and the rib height-to-hydraulic diameter ratio ($e/D_h$) is 0.075. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is constant at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for the same conditions using a commercial code FLUENT 6.1. The heat transfer data of the smooth duct for various Ro numbers agree well with not only the McAdams correlation but also the previous studies. The cross-rib turbulators significantly enhance heat/mass transfer in the passage by disturbing the main flow near the surfaces and generating one asymmetric cell of secondary flow skewing along the ribs. Because the secondary flow is induced in the first-pass and turning region, heat/mass transfer discrepancy is observed in the second-pass even for the stationary case. When the passage rotates, heat/mass transfer and flow phenomena change. Especially, the effect of rotation is more dominant than the effect of the ribs at the higher rotation number in the upstream of the second-pass.

Keywords

References

  1. Hwang, J. J. and Lai, Y. Y., 1998, 'Three-Dimensional Mixed Convection in a Rotating Multiple Pass Square Channel,' Int. J. Heat and Mass Transfer, Vol. 41, pp. 979-991 https://doi.org/10.1016/S0017-9310(97)00225-1
  2. Iacovides, H., Jackson, D. C., Kelemenis, G., Launder, B. E. and Yuan, Y. M., 1999, 'Experiments on Local Heat Transfer in a Rotating Square-Ended U-bend,' Int. J. Heat and Fluid Flow, Vol. 20, pp. 302-310 https://doi.org/10.1016/S0142-727X(99)00019-3
  3. Liou, T. M., Chen, C. C. and Chen, M. Y., 2001, 'TLCT and LDV Measurements of Heat Transfer and Fluid Flow in a Rotating Sharp Turning Duct,' Int. J. Heat and Mass Transfer, Vol. 44, pp. 1777-1787 https://doi.org/10.1016/S0017-9310(00)00221-0
  4. Murata, A. and Mochizuki, S., 1999, 'Effects of Cross-Sectional Aspect Ratio on Turbulent Heat Transfer in an Orthogonally Rotating Rectangular Smooth Duct,' Int. J. Heat and Mass Transfer, Vol. 42, pp. 3803-3814 https://doi.org/10.1016/S0017-9310(99)00058-7
  5. Won, J. H., Lee, S. Y. and Cho, H. H., 2001, 'Heat/Mass Transfer Characteristics in a Rotating Duct with $180^{\circ}$ Turn,' Transactions of KSME(B), Vol. 25, No. 3, pp. 405-413
  6. Kim, K. M., Kim, S. I., Kim, Y. Y., Rhee, D. H. and Cho, H. H., 2004, 'Detailed Measurement of Heat/Mass Transfer in a Rotating Two-Pass Duct (I),' Transactions of KSME(B), Vol. 28, No. 8, pp. 910-920 https://doi.org/10.3795/KSME-B.2004.28.8.910
  7. Al-Qahtani, M., Jang, Y. J., Chen, H. C. and Han, J. C., 2002, 'Flow and Heat Transfer in Rotating Two-Pass Rectangular Channels (AR=2) by Reynolds Stress Turbulence Model,' Int. J. Heat and Mass Transfer, Vol. 45, pp. 1823-1838 https://doi.org/10.1016/S0017-9310(01)00292-7
  8. Mochizuki, S., Beier, M. and Murata, A., 1996, 'Detailed Measurement of Convective Heat Transfer in Rotating Two-Pass Rib-Roughened Coolant Channels,' ASME Paper No. 96-TA-6
  9. Murata, A., Mochizuki, S. and Takahashi, T., 1999, 'Local Heat Transfer Measurement of an Orthogonally Rotating Square Duct with Angled Rib Turbulators,' Int. J. Heat and Mass Transfer, Vol. 42, pp. 3047-3056 https://doi.org/10.1016/S0017-9310(99)00004-6
  10. Azad, G. S., Uddin, M. J. Han, J. C., Moon, H. K. and Glezer, B., 2002, 'Heat Transfer in a Two-Pass Rectangular Rotating Channel with 45-deg Angled Rib Turbulators,' J. Turbomacinery, Vol. 124, pp. 251-259 https://doi.org/10.1115/1.1450569
  11. Fu, W. L., Wright, L. M. and Han, J. C., 2004, 'Heat Transfer in Two-Pass Rotating Rectangular Channels (AR=1:2 and AR=1:4) with $45^{\circ}$ Angled Rib Turbulators,' ASME Paper No. GT2004-53261
  12. Rathjen, L. Hennecke, D. K., Sivade, C. and Semmler, K., 2002, 'Detailed Experimental and Numerical Heat/Mass Transfer Investigation in a Rotating Two-Pass Coolant Channel with Staggered $45^{\circ}$ Ribs,' 9th International Symposium on Transport Phenomena and Dynamic of Rotating Machinery, Paper No. HT-ABS-034
  13. Cho, H. H., Lee, S. Y. and Rhee, D. H., 2001, 'Heat Transfer Characteristics in a Two-Pass Rotating Rectangular Duct with $70^{\circ}$Attack Angle Ribs,' International Conference on Energy Conversion and Application (ICECA 2001), pp. 605-610
  14. Goldstein, R. J. and Cho, H. H., 1995, 'A Review of Mass Transfer Measurements Using Naphthalene Sublimation,' Experimental Thermal and Fluid Science, Vol. 10, pp. 416-434 https://doi.org/10.1016/0894-1777(94)00071-F
  15. Kline, S. J. and McClintock, F. A., 1953, 'Describing Uncertainty in Single-Sample Experiments,' Mechanical Engineering, Vol. 75, pp. 3-8
  16. McAdams, W. H., 1942, 'Heat Transmission, 2nd Edition,' McGraw-Hill, New York