Analysis of heat transfer and flow over a rotating cylinder at subcritical Reynolds numbers based on Taguchi method

Abstract

The flow past the rotating circular cylinder and the effect of buoyancy on heat transfer char-acteristics are studied numerically for the Reynolds number of 20 and 40 and the Prandtl number of 0.7. The lift and drag coefficients, Strouhal number, and local Nusselt number on the cylinder are studied under the sway of combined buoyancy (at the Richardson num-ber varies from 0 to 2) and different rotational directions. Although the interaction between buoyancy and rotation is a puzzling heat transfer problem, the direction of rotation is found to have significant effects on the flow patterns and heat transfer rate. The main innovation of the present work is to determine the extreme points of Nusselt numbers when different conditions are applied. For a positive rotation, the maximum local Nusselt number is at θ=225o, and the minimum local Nusselt number is at θ=100o. In contrast, for a negative rotation, the maxi-mum and minimum local Nusselt numbers are at θ=140o and θ=270o, respectively. Applying Taguchi method, it is found that average Nusselt number is more dependent on Reynolds number than other factors. Additionally, it can be concluded that the direction of rotation can be used as a powerful tool to adjust the heat transfer rate and the required value of drag and lift. Consequently, without applying different rotation speeds, it would be difficult to stabilize the flow, and with the aid of Taguchi method, it is determined that rotation is deciding factor in stabilizing flow patterns. The results are in good agreement with the experimental results.

Keywords

• Thermal Buoyancy
• Rotational Cylinder
• Vortex Shedding
• Aerodynamic Force
• Taguchi Method

References

1. REFERENCES
2. [1] Jain PC, Lohar BL. Unsteady mixed convection heat transfer from a horizontal circular cylinder. J Heat Transf 1979;101:126131. [CrossRef]
3. [2] Yang H, Zhang W, Zhu Z. Unsteady mixed convection in a square enclosure with an inner cylinder rotating in a bi-directional and time-periodic mode. Int J Heat Mass Transf 2019;136:563580. [CrossRef]
4. [3] Biswas, G. and S. Sarkar. Effect of thermal buoyancy on vortex shedding past a circular cylinder in cross-flow at low Reynolds numbers. Int J Heat Mass Transf 2009;52:18971912. [CrossRef]
5. [4] Paramane, S.B. and A. Sharma. Effect of cross-stream buoyancy and rotation on the free-stream flow and heat transfer across a cylinder. International J Thermal Sci 2010;49:20082025. [CrossRef]
6. [5] Al-Sumaily GF, Dhahad HA, Hussen HM, Thompson MC. Influence of thermal buoyancy on vortex shedding behind a circular cylinder in parallel flow. Int J Therm Sci 2020;156:106434. [CrossRef]
7. [6] Chatterjee D, Sinha C. Influence of thermal buoyancy on vortex shedding behind a rotating circular cylinder in cross flow at subcritical Reynolds numbers. J Heat Transf 2014;136:051704. [CrossRef]
8. [7] Nguyen, HD, Paik S, Douglass R. Unsteady mixed convection about a rotating circular cylinder with small fluctuations in the free-stream velocity. Int J Heat Mass Transf 1996;39:511525. [CrossRef]

9. [8] Elghnam RI. Experimental and numerical investigation of heat transfer from a heated horizontal cylinder rotating in still air around its axis. Ain Shams Eng J 2014;5:177185. [CrossRef]
10. [9] Luo X, Zhang W, Dong H, Kumar Thakur A, Yang B, Zhao W. Numerical analysis of heat transfer enhancement of fluid past an oscillating circular cylinder in laminar flow regime. Prog Nucl Energy 2021;139:103853. [CrossRef]
11. [10] Wan H, DesRoches JA, Palazotto AN, Patnaik SS. Vortex-induced vibration of elliptic cylinders and the suppression using mixed-convection. J Fluids Struct 2021;103:103297. [CrossRef]
12. [11] Mahir N, Altaç Z. Numerical investigation of flow and combined natural-forced convection from an isothermal square cylinder in cross flow. Int J Heat Fluid Flow 2019;75:103121. [CrossRef]
13. [12] Rashidi MM, Sadri M, Sheremet MA. Numerical simulation of hybrid nanofluid mixed convection in a lid-driven square cavity with magnetic field using high-order compact scheme. Nanomaterials 2021;11:2250. [CrossRef]
14. [13] Erfani E, Rashidi MM Parsa AB. The modified differential transform method for solving off-centered stagnation flow toward a rotating disc. Int J Comput Methods 2010;7:655670. [CrossRef]
15. [14] Barati E, Biabani M, Zarkak MR. Numerical investigation on vortex-induced vibration energy harvesting of a heated circular cylinder with various cross-sections. Int Commun Heat Mass Transf 2022;132:105888. [CrossRef]
16. [15] Hussain S, Jain J, Seth G, Rashidi M. Free convective heat transfer with hall effects, heat absorption and chemical reaction over an accelerated moving plate in a rotating system. J Magn Magn Mater 2017;422:112123. [CrossRef]
17. [16] ANSYS Inc. ANSYS Fluent Theory Guide. 14.0 Theory Guide. Pennsylvania, USA: ANSYS INC; 2011, p. 218–221.
18. [17] Dennis SCR, Hudson J, Smith N. Steady laminar forced convection from a circular cylinder at low Reynolds numbers. Phys Fluids 1968;11:933940. [CrossRef]
19. [18] Ding H, Shu C, Yeo K, Xu D. Simulation of incompressible viscous flows past a circular cylinder by hybrid FD scheme and meshless least square-based finite difference method. Comput Methods Appl Mech Eng 2004;193:727744. [CrossRef]
20. [19] Tuann S-Y, Olson MD. Numerical studies of the flow around a circular cylinder by a finite element method. Comput Fluids 1978;6:219240. [CrossRef]
21. [20] Badr H. Laminar combined convection from a horizontal cylinder—parallel and contra flow regimes. Int J Heat Mass Transf 1984;27:1527. [CrossRef]
22. [21] Chang, K.-S. and J.-Y. Sa. The effect of buoyancy on vortex shedding in the near wake of a circular cylinder. J Fluid Mech1990;220:253266. [CrossRef]
23. [22] Javadpour SM, Abadi EAJ, Akbari OA, Goharimanesh M. Optimization of geometry and nano-fluid properties on microchannel performance using Taguchi method and genetic algorithm. International Commun Heat Mass Transf 2020;119:104952. [CrossRef]
24. [23] Ruefer H. Living without Mathematical Statistics: Accurate Analysis, Diagnosis, and Prognosis Based on the Taguchi Method. New York: Springer; 2018. [CrossRef]
25. [24] Chatterjee D, Sinha C. Effect of Prandtl number and rotation on vortex shedding behind a circular cylinder subjected to cross buoyancy at subcritical Reynolds number. Int Commun Heat Mass Transf 2016;70:18. [CrossRef]