Abstract
Unsteady laminar flow with convective heat transfer through a curved square duct rotating at a constant angular velocity about the center of curvature is investigated numerically by using a spectral method, and covering a wide range of the Taylor number-300≤Tr≤1000 for the Dean number Dn = 1000. A temperature difference is applied across the vertical sidewalls for the Grashof number Gr = 100, where the outer wall is heated and the inner wall cooled, the top and bottom walls being adiabatic. Flow characteristics are investigated with the effects of rotational parameter, Tr, and the pressure-driven parameter, Dn, for the constant curvature 0.001. Time evolution calculations as well as their phase spaces show that the unsteady flow undergoes through various flow instabilities in the scenario 'multi-periodic → chaotic → steady-state → periodic → multi-periodic → chaotic', if Tr is increased in the positive direction. For negative rotation, however, time evolution calculations show that the flow undergoes in the scenario 'multi-periodic → periodic → steady-state', if Tr is increased in the negative direction. Typical contours of secondary flow patterns and temperature profiles are obtained at several values of Tr, and it is found that the unsteady flow consists of two-to six-vortex solutions if the duct rotation is involved. External heating is shown to generate a significant temperature gradient at the outer wall of the duct. This study also shows that there is a strong interaction between the heating-induced buoyancy force and the centrifugal-Coriolis instability in the curved channel that stimulates fluid mixing and consequently enhances heat transfer in the fluid.
| Original language | English |
|---|---|
| Title of host publication | International Conference on Mechanical Engineering: Proceedings of the 11th International Conference on Mechanical Engineering, ICME 2015 |
| Publisher | American Institute of Physics Inc. |
| Volume | 1754 |
| ISBN (Electronic) | 9780735414129 |
| DOIs | |
| Publication status | Published - Jul 12 2016 |
| Event | 11th International Conference on Mechanical Engineering, ICME 2015 - Dhaka, Bangladesh Duration: Dec 18 2015 → Dec 20 2015 |
Other
| Other | 11th International Conference on Mechanical Engineering, ICME 2015 |
|---|---|
| Country | Bangladesh |
| City | Dhaka |
| Period | 12/18/15 → 12/20/15 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
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Unsteady laminar flow with convective heat transfer through a rotating curved square duct with small curvature. / Mondal, Rabindra Nath; Roy, Titob; Shaha, Poly Rani; Yanase, Shinichiro.
International Conference on Mechanical Engineering: Proceedings of the 11th International Conference on Mechanical Engineering, ICME 2015. Vol. 1754 American Institute of Physics Inc., 2016. 040002.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
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TY - GEN
T1 - Unsteady laminar flow with convective heat transfer through a rotating curved square duct with small curvature
AU - Mondal, Rabindra Nath
AU - Roy, Titob
AU - Shaha, Poly Rani
AU - Yanase, Shinichiro
PY - 2016/7/12
Y1 - 2016/7/12
N2 - Unsteady laminar flow with convective heat transfer through a curved square duct rotating at a constant angular velocity about the center of curvature is investigated numerically by using a spectral method, and covering a wide range of the Taylor number-300≤Tr≤1000 for the Dean number Dn = 1000. A temperature difference is applied across the vertical sidewalls for the Grashof number Gr = 100, where the outer wall is heated and the inner wall cooled, the top and bottom walls being adiabatic. Flow characteristics are investigated with the effects of rotational parameter, Tr, and the pressure-driven parameter, Dn, for the constant curvature 0.001. Time evolution calculations as well as their phase spaces show that the unsteady flow undergoes through various flow instabilities in the scenario 'multi-periodic → chaotic → steady-state → periodic → multi-periodic → chaotic', if Tr is increased in the positive direction. For negative rotation, however, time evolution calculations show that the flow undergoes in the scenario 'multi-periodic → periodic → steady-state', if Tr is increased in the negative direction. Typical contours of secondary flow patterns and temperature profiles are obtained at several values of Tr, and it is found that the unsteady flow consists of two-to six-vortex solutions if the duct rotation is involved. External heating is shown to generate a significant temperature gradient at the outer wall of the duct. This study also shows that there is a strong interaction between the heating-induced buoyancy force and the centrifugal-Coriolis instability in the curved channel that stimulates fluid mixing and consequently enhances heat transfer in the fluid.
AB - Unsteady laminar flow with convective heat transfer through a curved square duct rotating at a constant angular velocity about the center of curvature is investigated numerically by using a spectral method, and covering a wide range of the Taylor number-300≤Tr≤1000 for the Dean number Dn = 1000. A temperature difference is applied across the vertical sidewalls for the Grashof number Gr = 100, where the outer wall is heated and the inner wall cooled, the top and bottom walls being adiabatic. Flow characteristics are investigated with the effects of rotational parameter, Tr, and the pressure-driven parameter, Dn, for the constant curvature 0.001. Time evolution calculations as well as their phase spaces show that the unsteady flow undergoes through various flow instabilities in the scenario 'multi-periodic → chaotic → steady-state → periodic → multi-periodic → chaotic', if Tr is increased in the positive direction. For negative rotation, however, time evolution calculations show that the flow undergoes in the scenario 'multi-periodic → periodic → steady-state', if Tr is increased in the negative direction. Typical contours of secondary flow patterns and temperature profiles are obtained at several values of Tr, and it is found that the unsteady flow consists of two-to six-vortex solutions if the duct rotation is involved. External heating is shown to generate a significant temperature gradient at the outer wall of the duct. This study also shows that there is a strong interaction between the heating-induced buoyancy force and the centrifugal-Coriolis instability in the curved channel that stimulates fluid mixing and consequently enhances heat transfer in the fluid.
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U2 - 10.1063/1.4958362
DO - 10.1063/1.4958362
M3 - Conference contribution
VL - 1754
BT - International Conference on Mechanical Engineering: Proceedings of the 11th International Conference on Mechanical Engineering, ICME 2015
PB - American Institute of Physics Inc.
ER -