Experimentation was conducted to examine the heat transfer and pressure drop characteristics in a rib-roughened rectangular passage with aspect ratio 2:1 for four rib configurations: 90 deg, 75 deg, 60 deg and 45 deg oblique ribs. The ribs were attached to two opposing long side walls instead of short side walls. In this study the oblique ribs were intended to function as secondary flow inducers as well as turbulators to improve the heat transfer of the bottom wall (one of the short side walls). The results revealed that, in order to enhance the heat transfer of the bottom wall, the oblique ribs should be arranged so that the secondary flow along the ribs hits the top wall instead of the bottom wall. Flow visualization test was performed to understand the heat transfer mechanisms. It was confirmed that the heat transfer enhancement at the bottom wall was attributed to the rib-induced secondary flow where the flow along the ribs hit the top wall, turned back and carried cold air from the passage core region towards the bottom wall. The highest average heat transfer was achieved for the 60 deg rib pattern due to the strong rotational momentum of the secondary flow and higher heat transfer enhancement on the rib-roughened walls in comparison to the other three rib patterns.
Issue Section:
Forced Convection
1.
Johnson, B. V., Wagner, J. H., Steuber, G. D., and Yeh, F. C., 1993, “
Heat Transfer in Rotating Serpentine Passages With Selected Model Orientations for Smooth or Skewed Trip Walls,” ASME Paper 93-GT-305.
2.
Taslim
, M. E.
, 1991
, “An Experimental Investigation of Heat Transfer Coefficients in a Spanwise Rotating Channel With Two Opposite Rib-Roughened Walls
,” ASME J. Turbomach.
, 113
, pp. 75
–82
.3.
Rau, G., Cakan, M., Moeller, D., and Arts, T., 1996, “
The Effect of Periodic Ribs on the Local Aerodynamic and Heat Transfer Performance of a Straight Cooling Passage,” Proceedings, International Gas Turbine and Aeroengine Congress and Exhibition, Birmingham, UK, June 10–13, 1996.
4.
Mochizuki
, S.
, Murata
, A.
, and Fukunaga
, M.
, 1997
, “Effects of Rib Arrangement on Pressure Drop and Heat Transfer in a Rib-roughened Channel with a Sharp 180° Turn
,” ASME J. Turbomach.
, 119
, pp. 610
–616
.5.
Han
, J. C.
, 1985
, “Heat Transfer Enhancement in Channels With Turbulence Promoters
,” ASME J. Eng. Gas Turbines Power
, 106
, pp. 774
–781
.6.
Kiml, R., 2000, “
Internal Cooling of Gas Turbine Blades,” Doctoral thesis, Tokyo University of Agriculture and Technology, pp. 1–190.
7.
Wagner
, J. H.
, 1992
, “Heat Transfer in Rotating Serpentine Passages With Trips Normal to the Flow
,” ASME J. Turbomach.
, 114
, pp. 847
–457
.8.
Dutta
, S.
, Han
, J.-C.
, and Zhang
, Y.-M.
, 1995
, “Influence of Rotation on Heat Transfer from a Two-Pass Channel with Periodically Placed Turbulence and Secondary Flow Promoters
,” Int. J. Rotating Mach.
, 1
, pp. 129
–144
.9.
Dutta, S., Andrews, J. M., and Han, J.-C., 1996, “Prediction of Turbulent Flow and Heat Transfer in Rotating Square and Rectangular Smooth Channels,” ASME Paper 96-GT-234.
10.
Dutta
, S.
, and Han
, J.-C.
, 1996
, “Local Heat Transfer in Rotating Smooth and Ribbed Two-Pass Square Channels with Three Channel Orientations
,” ASME J. Turbomach.
, 118
, pp. 587
–584
.11.
El-Husayni
, H. A.
, Taslim
, M. E.
, and Kercher
, D. M.
, 1994
, “Experimental Heat Transfer Investigation of Stationary and Orthogonally Rotating Asymmetric and Symmetric Heated Smooth and Turbulated Channels
,” ASME J. Turbomach.
, 116
, pp. 124
–132
.12.
Mochizuki, S., Beier, M., and Murata, A., 1996, “
Detailed Measurement of Convective Heat Trans. In Rotating Two-Pass Rib-Roughened Coolant Channels,” ASME Paper 96-TA-6.
13.
Taslim, M. E., Li, T., and Kercher, D. M., 1994, “
Experimental Heat Transfer and Friction in Channels Roughened with Angled V shaped and Discrete Ribs on Two Opposite Walls,” Paper 94-GT-163.
14.
Hu, Z., and Shen, J., 1996, “
Secondary Flow and It’s Contribution to Heat Transfer Enhancement in a Blade Cooling Passage with Discrete Ribs,” Proceedings, International Gas Turbine and Aeroengine Congress & Exhibition Birmingham, UK, June 10–13, 1996.
15.
Han
, J. C.
, and Zhang
, Y. M.
, 1992
, “High Performance Heat Transfer Ducts with Parallel, Broken, and V-shaped ribs
,” Int. J. Heat Mass Transf.
, 35
, pp. 513
–523
.16.
Han
, J. C.
, Zhang
, Y. M.
, and Lee
, C. P.
, 1991
, “Augmented Heat Transfer in Square Channels With Parallel, Crossed, and V-Shaped Angled Ribs
,” ASME J. Heat Transfer
, 113
, pp. 590
–596
.17.
Ekkad
, S. V.
, and Han
, J.-C.
, 1997
, “Detailed Heat Transfer Distribution in Two-Pass Square Channels with Rib Turbulators
,” Int. J. Heat Mass Transf.
, 40
, No. 11
, pp. 2525
–2537
.18.
Johnson
, B. V.
, Wagner
, J. H.
, Steuber
, G. D.
, and Yeh
, F. C.
, 1994
, “Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow
,” ASME J. Turbomach.
, 116
, pp. 113
–123
.19.
Cheng, K. C., Shi, L., and Kurokawa, M., 1992, “
Visualization of Flow Patterns in a 180-Degree Sharp Turn of a Square Duct,” Proceedings, 4th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, USA, Hawaii, A, pp. 124–132.
20.
Cheng, K. C., and Shi, L., 1996, “
Visualization of Flow Patterns in a 90-Degree Sharp Turn of a Square Duct,” Proceedings, 6th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, USA, Hawaii, 2, pp. 651–660.
21.
Metzger
, D. E.
, Plevich
, C. W.
, and Fan
, C. S.
, 1984
, “Pressure Loss Through Sharp 180 Degree Turn in Smooth Rectangular Channels
,” Trans. ASME J. Eng. Gas Turbines Power
, 106
, pp. 677
–681
.22.
Kiml, R., Mochizuki, S., and Murata, A., 1998, “
Influence of 180 Degree Sharp Turn on the Heat Transfer and Flow Behavior in a Smooth Square Cross Sectional Serpentine Channel,” 8th International Symposium on Flow Visualization, CD Rom Proc. of 8th International Symposium on Flow Visualization, Sorrento, Italy (Paper No. 067), pp. 1–8.
23.
Zhang
, Y. M.
, Gu
, W. Z.
, and Han
, J. C.
, 1994
, “Heat Transfer and Friction in Rectangular Channels Ribbed and Ribbed-Grooved Walls
,” ASME J. Heat Transf.
, 116
, pp. 58
–65
.24.
Kiml
, R.
, Mochizuki
, S.
, and Murata
, A.
, 2000
, “Influence of the Gap Size between Side Walls and Ribs on the Heat Transfer in a Stationary and Rotating Straight Rib-Roughened Duct
,” Int. J. Rotating Mach.
6
, No. 4
, pp. 253
–263
.25.
Kiml, R., Mochizuki, S., and Murata, A., 2000, “
Function of Ribs as Turbulators and Secondary Flow Inducers,” 9th International Symposium on Flow Visualization, CD Rom Proc. of 9th International Symposium on Flow Visualization, Edinburgh, United Kingdom (Paper File No. 164), pp. 1–10.
26.
Hirota, M., Fujita, H., Yokosawa, H., and Tanaka, Y., 1996, “
Characteristics of Turbulent Flow in a Rectangular Duct With Rib-Roughened Long-Side Walls,” Proc. of the 9th International Symposium on Transport Phenomena in Thermal-Fluids Engineering, Singapore, June 25–28, 1996.
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by ASME
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