# Numerical analysis of heat transfer and friction factor in two-pass channels with variable rib shapes

Numerical analysis of heat transfer and friction factor in two-pass channels with variable rib shapes

Mechanical Engineering Department, National Institute of Technology Srinagar, J & K, India

Corresponding Author Email:
arjumand.beigh@yahoo.co.in
Page:
40-48
|
DOI:
https://doi.org/10.18280/ijht.360106
17 August 2017
|
Accepted:
12 January 2018
|
Published:
31 March 2018
| Citation

OPEN ACCESS

Abstract:

Present investigation deals with the analysis of heat transfer and friction factor for turbulent flow of air through a two-pass square channel, having ribs of various cross-sections. The cases undertaken are numerically investigated by commercial software ‘Comsol 5.2a’ using Standard k-ε model. The emphasis is towards investigating the potential impact of differing the shape of ribs for a comparative roughness pitch (p/e) of 10. Four different test cases were analyzed: square, boot, trapezoidal and house rib designs for the Reynold’s number range of 5000-52000. The Nusselt number results obtained were validated by comparing with the experimentally and computationally obtained data from earlier studies under similar conditions. The impact of the Reynold’s number on the overall performance of various rib shapes has been also investigated. The increment in average Nusselt number over that of the conventional square rib roughened channel is 1.19 and friction factor gets lowered by a factor of 1.3 as compared to square ribs respectively. The analysis shows that characteristics of heat transfer distribution and fluid flow in between the ribs are significantly influenced due to rib design and the boot-shaped rib design shows better heat transfer and friction factor performance than conventional square ribs, and therefore guarantees an enhanced thermo-hydraulic performance.

Keywords:

local heat transfer coefficient, numerical simulation, ribs, turbine blade internal cooling

1. Introduction
2. Computational Details
3. Grid Independence Study
4. Data Reduction
5. Computational Results
6. Conclusions
Nomenclature
References

[1] Han JC, Dutta S, Ekkad SV. (2000). Gas turbine heat transfer and cooling technology. CRC Press, New York, Taylor and Francis Group, 287-355.

[2] Webb RL, Eckert ERG. (1972). Application of rough surfaces to heat exchanger design. Int. J. of Heat Mass Transfer 15(9): 1647–1658. https://doi.org/10.1016/0017-9310(72)90095-6

[3] Acharya S, Dutta S, Myrum TA, Baker RS. (1993). Periodically developed flow and heat transfer in a ribbed duct. Int. J. of Heat and Mass Transfer 36(8): 2069–2082. https://doi.org/10.1016/S0017-9310(05) 80138-3

[4] Han JC, Park JS. (1988). Developing heat transfer in rectangular channels with rib turbulators. Int. J. of Heat and Mass Transfer 31(1): 183–195. https://doi.org/10.1016/0017-9310(88)90235-9

[5] Rau G, Cakan M, Moeller D, Arts T. (1998). The Effect of periodic ribs on the local aerodynamic and heat transfer performance of a straight cooling channel. ASME J. of Turbomachinery 120(2): 368–375. https://doi. org/ 10.1115/1.2841415

[6] Aliaga DA, Lamb JP, Klein DE. (1994). Convection heat transfer distributions over plates with square ribs from infrared thermography measurements. Int. J. of Heat and Mass Transfer 37(3): 363–374. https://doi.org/10.1016/0017-9310(94)90071-X

[7] Tanda G. (2011). Effect of rib spacing on heat transfer and friction in a rectangular channel with 45oangled rib turbulators on one/two walls. Int. J. of Heat and Mass Transfer 54(54): 1081–1090. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2010.11.015

[8] Chandra PR, Alexander CR, Han JC. (2003). Heat transfer and friction behaviors in rectangular channels with varying number of ribbed walls. Int. J. of Heat and Mass Transfer  46(3): 481–495. https://doi.org/10.1016/S0017-9310(02)00297-1

[9] Tariq A, Panigrahi PK, Muralidhar K. (2004). Flow and heat transfer in the wake of a surface mounted rib with a slit. Experiments in Fluids 37(5): 701–719. https://doi.org/ 10.1007/s00348-004-0861-8

[10] Hwang JJ. (1998). Heat transfer- friction characteristic   comparison in rectangular ducts with slit and solid ribs mounted on one wall. ASME J. of Heat Transfer 120(3): 709–716. https://doi.org/ 10.1115/ 1.2824340

[11] Taslim ME, Li T, Kercher DM. (1996). Experimental heat transfer and friction in channels roughened with angled, V-shaped and discrete ribs on two opposite walls. Journal Turbomach 4: 20-8. https://doi.org/ 10.1115/94-GT-163

[12] Liou TM, Hwang JJ. (1992). Turbulent heat transfer augmentation and friction in periodic fully developed channel ﬂows. ASME J.of Heat Transfer 114(1): 56–64. https://doi.org/ 10.1115/1.2911267

[13] Han JC, Glicksman LR, Rohsenow WM. (1978). An investigation of Heat Transfer and Friction for Rib Roughened Surfaces. Int J. of Heat and Mass Transfer 21(8): 1143–1156. https://doi.org/10.1016/0017-9310(78)90113-8

[14] Lockett JF, Collins MW. (1990). Holographic interferometry applied to rib-roughness heat transfer in turbulent flow. Int. J. of Heat and Mass Transfer 33(11): 2439–2449. https://doi.org/ 10.1016/0017-9310(90)90002-C

[15] Wang L, Sunden B. (2007). Experimental investigation of local heat transfer in a square duct with various-shaped ribs. Int. J. of Heat Mass Transfer 18(3): 759–766. https://doi.org/10.1080/ 08916150590953397

[16] Liou TM, Hwang JJ. (1993). Effect of ridge shapes on turbulent heat transfer and friction in rectangular channel. Int. J. Heat Mass Transfer 36(4): 931–940. https://doi.org/10.1016/S0017-9310(05)80277-7

[17] Promvonge P, Thianpong C. (2008). Thermal performance assessment of turbulent channel flows over different shaped ribs. Int. Commun. Heat Mass Transfer 35(10): 1327–1334. https://doi.org/10.1016/ j.icheatmasstransfer.2008.07.016

[18] Liu P, Gao HM, Liu H. (2010). Numerical simulation of heat transfer and resistance pattern in channels with different ribs. Int. Conf. Comput. Des. https://doi.org/ 10.1109/2010.5541336

[19] Wongcharee K, Changcharoen W, Eiamsa-ard S. (2011). Numerical investigation of flow friction and heat transfer in a channel with various shaped ribs mounted on two opposite ribbed walls. Int. J. of Chem. Reactor Eng 9(1). https://doi.org/10.1515/1542-6580.2560

[20] Moon MA, Park MJ, Kim KY. (2014). Evaluation of heat transfer performances of various rib shapes. Int. J. of Heat and Mass Transfer 71. https://doi.org/10.1016/j.ijheatmasstransfer.2013.12.026

[21] Shevchuk IV, Jenkins SC, Weigand B, Wolfersdorf JV. (2011). Validation and analysis of numerical results for a varying aspect ratio two-pass internal cooling channel. J. of Heat Transfer 133(5): 051701-051708. https://doi.org/ 10.1115/1.4003080

[22] Ravi BV, Ekkad SV, Singh P. (2017). Numerical investigation of turbulent flow and heat transfer in two-pass ribbed channels.  Int. J. of Thermal Sciences 112: 31-43. https://doi.org/10.1016/  j. ijthermalsci. 2016.09.034

[23] Singh P, Ravi BV, Ekkad SV. (2016). Experimental and numerical study of heat transfer due to developing flow in a two-pass rib roughened square duct. Int. J. Heat Mass Transfer 102: 1245-56 https://doi.org/10.1016/j.ijheatmasstransfer.2016.07.015

[24] Jang YJ, Chen HC, Han JC. (2001). Computation of flow and heat transfer in two pass channels with 60

deg ribs. J. Heat Transfer 123(3): 563–575. https://doi.org/ 10.1115/1.1371931

[25] Saha K, Acharya S. (2013). Effect of bend geometry on heat transfer and pressure drop in a two-pass coolant square channel for a turbine. J. Turbomach 135(2) 763-71. https://doi.org/10.1115/1.4006665

[26] Han S, Goldstein RJ. (2008). The heat/mass transfer analogy for a simulated turbine blade. Int. J. of heat and mass transfer 51: 5209-5225. https://doi.org/10.1016/j.ijheatmasstransfer.2008.04.002

[27] Erelli R, Saha K, Panigrahi PK. (2015). Influence of turn geometry on turbulent fluid flow and heat transfer in a stationary two-pass square duct. Int. J. of Heat and Mass Transfer 89: 667–684. https://doi.org/10.1016/j.ijheatmasstransfer.2015.05.081

[28] Ekkad SV, Han JC. (1997). Detailed heat and mass transfer distribution in a two-pass Square channel with rib turbulators. Int. J. of Heat and Mass Transfer 40(11): 2525-2537. https://doi.org/10.1016/S0017-9310(96)00318-3

[29] Ooi A, Iaccarino G, Durbin PA, Behnia M. (2002) Reynolds averaged simulation of flow and heat transfer in ribbed ducts. Int. J. Heat and Fluid Flow 23(6): 750-757. https://doi.org/10.1016/ S0142-727X(02)00188-1

[30] Sleiti AK, Kapat JS. (2006). Comparison between EVM and RSM turbulence models in predicting flow and heat transfer in rib roughened channels. J Turbulence 7: 531-542. https://doi.org/ 10.1080/ 14685240500499343