Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-20T02:49:56.159Z Has data issue: false hasContentIssue false

Nusselt Number as Composite Functions of Aspect Ratio and Wall Inclination in Parallelogram Microchannels with Three Types of Thermal Boundary Conditions

Published online by Cambridge University Press:  09 September 2016

T.-M. Liou*
Affiliation:
Department of Power Mechanical EngineeringNational Tsing Hua UniversityHsinchu, Taiwan
H. Wang
Affiliation:
Department of Power Mechanical EngineeringNational Tsing Hua UniversityHsinchu, Taiwan
S.-P. Chan
Affiliation:
Department of Power Mechanical EngineeringNational Tsing Hua UniversityHsinchu, Taiwan
*
*Corresponding author (tmliou@pme.nthu.edu.tw)
Get access

Abstract

In this study, attention is focused on the numerical simulations of laminar fluid flow and heat transfer in straight smooth-walled parallelogram channels with various aspect ratios (α) and inclined angles (θ). The Reynolds number (Re), characterized by the channel hydraulic diameter and the working fluid of water, is fixed at 100. The examined α and θ range from 1 to 10 and 45° to 90°, respectively. Their effects on the thermal fluid features are explored under three thermal boundary conditions: constant wall temperature (TBC), constant axial heat transfer rate with constant peripheral temperature (H1BC), and constant wall heat flux (H2BC). The SIMPLE algorithm is employed for velocity–pressure coupling with the algebraic multigrid method, while the second-order upwind scheme is utilized for spatial discretization in pressure term; the momentum and energy equations are solved with a QUICK scheme; Least Squares Cell-Based Gradient Evaluation is applied for predicting scalar values at the cell faces and for computing secondary diffusion terms and velocity derivatives. One of the new findings is that there exists a critical value of θ = 70° below which the Nusselt number under H2BC increases with increasing α whereas beyond which the trend reverses, a result distinct from those computed with TBC and H1BC. Moreover, TBC is found to be a time-saving alternative to H1BC. Furthermore, both Nusselt numbers under the three thermal boundary conditions and friction factor times Re are successfully and compactly correlated with α and θ to offer useful reference for designing micro-cooling channels.

Type
Research Article
Copyright
Copyright © The Society of Theoretical and Applied Mechanics 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Cengel, Y. A., Heat Transfer: A Practical Approach, 2nd Edition, McGraw-Hill, New York, (2004).Google Scholar
2. Tuckerman, D. B. and Pease, R. F. W., “High-Performance Heat Sinking for VLSI,” IEEE Electron Device Letters, 2, pp. 126129 (1981).Google Scholar
3. Sobhan, C. B. and Garimella, S. V., “A Comparative Analysis of Studies on Heat Transfer and Fluid Flow in Microchannel,” Microscale Thermophysical Engineering, 5, pp. 293311 (2001).Google Scholar
4. Garimella, S. V. and Sobhan, C. B., “Transport in Microchannel-A Critical Review,” Annual Review of Heat Transfer, 13, pp. 150 (2003).Google Scholar
5. Lee, P. S., Garimella, S. V. and Liu, D., “Investigation of Heat Transfer in Rectangular Microchannel,” International Journal of Heat and Mass Transfer, 48, pp. 16881704 (2005).Google Scholar
6. Shah, R. K. and London, A. L., Advances in Heat Transfer: Laminar Flow Forced Convection in Ducts Supplement 1, Academic Press, San Diego, (1978).Google Scholar
7. Kakaç, S., Shah, R. K. and Aung, W., Handbook of Single-Phase Convective Heat Transfer, Wiley, New York, (1987).Google Scholar
8. Geyer, P. E., Fletcher, D. F. and Haynes, B. S., “Laminar Flow and Heat Transfer in a Periodic Trapezoidal Channel with Semi-Circular Cross-Section,” International Journal of Heat and Mass Transfer, 50, pp. 34713480 (2007).Google Scholar
9. Rosaguti, N. R., Fletcher, D. F. and Haynes, B. S., “A General Implementation of the H1 Boundary Condition in CFD Simulations of Heat Transfer in Swept Passages,” International Journal of Heat and Mass Transfer, 50, pp. 18331842 (2007).Google Scholar
10. Wibulswas, P., “Laminar-Flow Heat-Transfer in Non-Circular Ducts,” Ph. D. Dissertation, Department of Mechanical Engineering, University of London, London, England (1966).Google Scholar
11. Schmidt, F. W. and Newell, M. E., “Heat Transfer in Fully Developed Laminar Flow through Rectangular and Isosceles Triangular Ducts,” International Journal of Heat and Mass Transfer, 10, pp. 11211123 (1967).Google Scholar
12. Aparecido, J. B. and Cotta, R. M., “Thermally Developing Laminar Flow inside Rectangular Ducts,” International Journal of Heat and Mass Transfer, 33, pp. 341347 (1990).Google Scholar
13. Shah, R. K., “Laminar Flow Friction and Forced Convection Heat Transfer in Ducts of Arbitrary Geometry,” International Journal of Heat and Mass Transfer, 18, pp. 849862 (1975).Google Scholar
14. Lee, P. S. and Garimella, S. V., “Thermally Developing Flow and Heat Transfer in Rectangular Microchannel of Different Aspect Ratios,” International Journal of Heat and Mass Transfer, 49, pp. 30603067 (2006).Google Scholar
15. Dharaiya, V. V. and Kandlikar, S. G., “Numerical Investigation of Heat Transfer in Rectangular Microchannel Under H2 Boundary Condition during Developing and Fully Developed Laminar Flow,” Journal of Heat Transfer, 134, 020911 (2011).Google Scholar
16. Rostami, A. A. and Mortazavi, S. S., “Analytical Prediction of Nusselt Number in a Simultaneously Developing Laminar Flow between Parallel Plates,” International Journal of Heat and Fluid Flow, 11, pp. 4447 (1990).Google Scholar
17. Silva, J. B. C., Cotta, R. M. and Aparecido, J. B., “Analytical Solutions to Simultaneously Developing Laminar Flow inside Parallel-Plate Channels,” International Journal of Heat and Mass Transfer, 35, pp. 887895 (1992).Google Scholar
18. Spiga, M. and Morini, G. L., “Nusselt Numbers in Laminar Flow for H2 Boundary Conditions,” International Journal of Heat and Mass Transfer, 39, pp. 11651174 (1996).Google Scholar
19. Spiga, M. and Morini, G. L., “Laminar Heat Transfer between Parallel Plates as the Limiting Solution for the Rectangular Duct,” International Communications in Heat and Mass Transfer, 23, pp. 555562 (1996).Google Scholar
20. Savino, J. M. and Siegel, R., “Laminar Forced Convection in Rectangular Channels with Unequal Heat Addition on Adjacent Sides,” International Journal of Heat and Mass Transfer, 7, pp. 733741 (1964).Google Scholar
21. Gilbert, D. E., Leay, R. W. and Barrow, H., “Theoretical Analysis of Forced Laminar Convection Heat Transfer in the Entrance Region of an Elliptic Duct,” International Journal of Heat and Mass Transfer, 16, pp. 15011503 (1973).Google Scholar
22. Abdel-Wahed, R. M., Attia, A. E. and Hifni, M. A., “Experiments on Laminar Flow and Heat Transfer in an Elliptical Duct,” International Journal of Heat and Mass Transfer, 27, pp. 23972413 (1984).Google Scholar
23. Iqbal, M., Khatry, A. K. and Aggarwala, B. D., “On the Second Fundamental Problem of Combined Free and Forced Convection through Vertical Noncircular Ducts,” Applied Science Research, 26, pp. 183208 (1972).Google Scholar
24. Yilmaz, T. and Cihan, E., “General Equation for Heat Transfer for Laminar Flow in Ducts of Arbitrary Cross-Sections,” International Journal of Heat and Mass Transfer, 36, pp. 32653270 (1993).CrossRefGoogle Scholar
25. Liou, T. M., Chang, S. W., Chan, S. P. and Lin, A., “Influence of Entrance Geometry on Flow Field and Heat Transfer Performance in Stationary Two-Pass Smooth Parallelogram Channels,” International Journal of Heat and Mass Transfer (in press).Google Scholar
26. Liou, T. M., Chen, C. C. and Chen, M. Y., “TLCT and LDV Measurements of Heat Transfer and Fluid Flow in a Rotating Sharp Turning Duct,” International Journal of Heat and Mass Transfer, 44, pp. 17771787 (2001).Google Scholar
27. Liou, T. M., Chang, S. W., Yang, C. C., and Lan, Y. A., “Thermal Performance of a Radially Rotating Twin-Pass Smooth-Walled Parallelogram Channel,” Journal of Turbomachinery, 136, 121007 (2014).CrossRefGoogle Scholar
28. ANSYS Fluent User's Guide, ANSYS Inc. (2014).Google Scholar
29. Leonard, B. P., “A Stable and Accurate Convective Modelling Procedure Based on Quadratic Upstream Interpolation,” Computer Methods in Applied Mechanics and Engineering, 19, pp. 5998 (1979).Google Scholar
30. Chintada, S., Ko, K. H. and Anand, N. K., “Heat Transfer in 3-D Serpentine Channels with Right-Angle Turns,” Numerical Heat Transfer, Part A: Applications, 36, pp. 781806 (1999).Google Scholar
31. Bejan, A., Convection Heat Transfer, 4th Edition, John Wiley & Sons, New Jersey, (2013).CrossRefGoogle Scholar