## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Experimental investigation of flow and heat transfer characteristics on matrix ribbed channel

**ABSTRACT**

The effect of the rib width to height ratio t/e and width to pitch ratio t/p on the local heat transfer distribution in a rectangular matrix ribbed channel with two opposite in line 45º ribs are experimentally investigated for Reynolds Numbers from 54000 to 150000. The rib height to channel height ratio e/H is 0.5, t/p and t/e both varies in range of 0.3-0.5. And to simulate the actually situation in turbine blades, and provide useful direct results for turbine blade designers, the parameters are same with the blade. The experiments results show that, in comparison to fully developed flow in a smooth pipe of equivalent hydraulic diameter, the Nusselt number inside the matrix-ribbed rectangular channel is increased up to 5 to 9 times higher, while total pressure drop is enlarged by up to significant magnitude. The Nusselt number ratio increases with t/p and t/e increased. Semi-empirical heat transfer is developed for designing of cooling channel.

**KEYWORDS**

PAPER SUBMITTED: 2019-07-02

PAPER REVISED: 2019-09-11

PAPER ACCEPTED: 2019-09-19

PUBLISHED ONLINE: 2020-02-08

- Han, J. C., et al., Developing Heat Transfer in Rectangular Channels with Rib Turbulators, International Journal of Heat & Mass Transfer, 31 (1988), 1, pp. 183-195
- Hans, V. S. et al., Performance of Artificially Roughened Solar Air Heaters—A Review, Renewable & Sustainable Energy Reviews, 13 (2009), 8, pp. 1854-1869
- Han, J. C., Heat Transfer and Friction in Channels with Two Opposite Rib-roughened Walls, Journal of Heat Transfer, 106 (1984), 4, pp. 774-781
- Kim, K. M., et al., Optimal Design of Angled Rib Turbulators in a Cooling Channel, Heat & Mass Transfer, 45 (2009), 12, pp. 1617-1625
- AAlkhamis, N. Y., et al., Heat Transfer and Pressure Drop Correlations for Square Channels with V-shaped Ribs at High Reynolds Numbers, Journal of Heat Transfer, 133 (2011), 11, pp. 111901
- Lei, J., et al., Effect of Rib Spacing on Heat Transfer in a Two Pass Rectangular Channel (AR = 2:1) at High Rotation Numbers. Asme Turbo Expo: Turbine Technical Conference & Exposition, (2012)
- Sundén, B., Heat Transfer and Fluid Flow in Rib-roughened Rectangular Ducts, in: Heat Transfer Enhancement of Heat Exchangers (Eds. S. Kakaç, A. E. Bergles, F. Mayinger, H. Yüncü), Springer, Dordrecht, 1999, pp. 123-140.
- Maurer, M., et al., Experimental Study of Advanced Convective Cooling Techniques for Combustor Liners, Proceedings (Heat Transfer, Parts A and B), ASME Turbo Expo 2008: Power for Land, Sea, and Air, Berlin, Germany, 2008, Vol. 4, pp. 1779-1789
- Alfarawi, S., et al., Experimental Investigations of Heat Transfer Enhancement from Rectangular Duct Roughened by Hybrid Ribs, International Journal of Thermal Sciences, 118 (2017), pp. 123-138
- Liou, T. M., et al., Simulation and Measurement of Enhanced Turbulent Heat Transfer in a Channel with Periodic Ribs on One Principal Wall, International Journal of Heat and Mass Transfer, 36 (1993), 2, pp. 507-517
- Bailey, J. C., et al., Heat Transfer and Friction in Channels with Very High Blockage 45° Staggered Turbulators, Proceedings (Turbo Expo 2003, Parts A and B), ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference, Atlanta, Georgia, USA, 2003, 5, pp. 451-458
- Chanteloup, D., et al., Combined 3D Flow and Heat Transfer Measurements in a 2-pass Internal Coolant Passage of Gas Turbine Airfoils, Journal of Turbo machinery, 124 (2002), 4, pp. 710-718
- Viswanathan A K, Tafti D K. Detached eddy simulation of flow and heat transfer in fully developed rotating internal cooling channel with normal ribs. International Journal of Heat & Fluid Flow, 2006, 27(3):351-370.
- Carcasci, C., et al., Heat Transfer and Pressure Loss Measurements of Matrix Cooling Geometries for Gas Turbine Airfoils, Journal of Turbomachinery, 136 (2014), 12, pp. 121005
- Taslim, M. E., et al., Experimental Heat Transfer and Friction in Channels Roughened with Angled, V-shaped, and Discrete Ribs on Two Opposite Walls, Journal of Turbomachinery, 118 (1996), 1: V004T09A018
- Pandey, P.K. et al. A finite difference method for a numerical solution of elliptic boundary value problems. Applied Mathematics & Nonlinear Sciences, 3. (2018), 1, pp. 311-320.
- Alfonso, M.J.F.I., et al. Some Improvements on Relativistic Positioning Systems. Applied Mathematics & Nonlinear Sciences, 3 (2018), 1, pp. 161-166.
- Luan, Y., et al., Numerical Investigation on Flow and Heat Transfer in Matrix Cooling Channels for Turbine Blades, Proceedings (Heat Transfer), ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, Seoul, South Korea, 2016, 5B, pp. V05BT11A005