Aplicação de técnica de imageamento térmico na determinação do número de Nusselt em uma placa plana aquecida

Authors

DOI:

https://doi.org/10.26512/ripe.v5i2.28661

Keywords:

Imageamento térmico. Convecção forçada. Placa plana, experimentação em transferência de calor

Abstract

Experimental technique was applied to evaluate the thermal field in a smooth flat plate under forced convection. The technique consists in capture the thermal image over different substrates built from different materials and peculiarities. Each substrate was heated by a constant heat source controlled by a power suplly Minipa and the thermal image was captured by a Thermal Camera Fluke™ Ti 125placed 120 mm from the heated pieces. The heated piece was inserted inside an aerodynamic channel whose the free stream velocity U¥ was controlled by a frequency inverter, and therefore, changing the Reynolds number. The experiments were run under ReL up to 6´ 104. The Reynolds number is based on the free stream velocity, the plate length and the kinematic viscosity of the fluid,n. The Prandlt number, based on the molecular diffusion and heat diffusion, n / a - ratio was computed to be 0.70. The outcomes obtained in the experimental campaign successfully described the local Nusselt number as   Nu = C RexmPrn, where C, m and n, were computed as 0.031; 0;85 and 1/3, respectively. In order to maximize the convective heat transfer processes over the conduction we spitted up the flat plate along its length.

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References

1. Ahmed, M. R., and Talama, F., 2008. Flow characteristics and local heat transfer rates for a heated circular cylinder in a crossflow of air. International Journal of Fluid Mechanics Research, 35(1).
2. Blair, M.F., 1983a. Influence of free-stream turbulence on turbulent boundary layer heat transfer and mean profile development. Part I”” Experimental Data, Journal of Heat Transfer 105, 33”“40.
3. Blair, M.F., 1983b. Influence of free-stream turbulence on turbulent boundary layer heat transfer and mean profile development. Part II”” analysis of results, Journal of Heat Transfer 105, 41”“47.
4. Bejan, A. Convection Heta Transfer, 3nd ed., Wiley, New York, 2004.
5. Das, R. C., 2017. Multi-scale analysis of turbulent thermal boundary layer with zero pressure gradient.
6. Dyban, E.P., Epick, E.Y. and Surpun, T.T., 1977. Characteristics of the laminar layer with increased turbulence of the outer stream, Int. Chem. Eng. 17(3), 501”“504.
7. Jakkareddy, P.S. and Balaji, C., 2018. "A non-intrusive technique to determine the spatially varying heat transfer coefficients in a flat plate with flush mounted heat sources." International Journal of Thermal Sciences 131: 144-159.
8. Kays W. M. and Crawford M. E., 1983. Convective Heat and Mass Transfer, 3rd. ed., McGraw Hill, New York, 163.
9. Nakamura, H. and Igarashi, T., 2006. "Measurements of Time-Space Distribution of Convective Heat Transfer Using a Thin Carbon-Film." ICHMT DIGITAL LIBRARY ONLINE. Begel House Inc.
10. MacMullin, R. Elrod, W. and Rivir, R., 1989. Free-stream turbulence from a circular wall jet on a flat plate heat transfer and boundary layer flow. Journal of Turbomachinery, 111(1), 78-86.
11. Mehendale, A. B. Han, J. C. and Ou, S., 1991. Influence of high mainstream turbulence on leading edge heat transfer. Journal of Heat Transfer, 113(4), 843-850.
12. Melina, G. Bruce, P. J. K. Nedić, J. Tavoularis, S. and Vassilicos, J. C., 2018. Heat transfer from a flat plate in inhomogeneous regions of grid-generated turbulence. International Journal of Heat and Mass Transfer, 123, 1068-1086.
13. Nakamura, H. Takaki, S. and Yamada, S., 2011. "Spatio-temporal characteristics of heat transfer in separated and reattaching flows." ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2011.
14. Nakamura, H., 2007. "Measurements of time-space distribution of convective heat transfer to air using a thin conductive-film." TSFP DIGITAL LIBRARY ONLINE. Begel House Inc.
15. Nakamura, H., 2009. "Frequency response and spatial resolution of a thin foil for heat transfer measurements using infrared thermography." International Journal of Heat and Mass Transfer 52.21-22: 5040-5045.
16. Nakamura, Hajime, and Yamada, S., 2013. "Quantitative evaluation of spatio-temporal heat transfer to a turbulent air flow using a heated thin-foil." International Journal of Heat and Mass Transfer 64: 892-902.
17. Nakamura, H. and Yamada, S., 2017. "Fast infrared imaging of turbulent heat transfer." Selected Papers from the 31st International Congress on High-Speed Imaging and Photonics. Vol. 10328. International Society for Optics and Photonics.
18. Péneau, F. Boisson, H. C. Kondjoyan, A. and Djilali, N., 2004. Structure of a flat plate boundary layer subjected to free-stream turbulence. International Journal of Computational Fluid Dynamics, 18(2), 175-188.
19. Yamada, S. and Nakamura, H., 2015. "Spatial correlation of velocity and heat transfer downstream of a backward facing step using 2D-3C PIV and IR thermography." TSFP DIGITAL LIBRARY ONLINE. Begel House Inc., 2015.
20. Yamada, S. and Nakamura, H., 2016 "Construction of 2D-3C PIV and high-speed infrared thermography combined system for simultaneous measurement of flow and thermal fluctuations over a backward facing step." International Journal of Heat and Fluid Flow 61: 174-182.
21. Young, C. D. Han, J. C. Huang, Y. and Rivir, R. B., 1992. Influence of jet-grid turbulence on flat plate turbulent boundary layer flow and heat transfer. Journal of heat transfer, 114(1), 65-72.

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Published

2020-02-17

How to Cite

de Almeida, P. P. S., Vila, J. L. R., Goulart, J. N. V., Nunes, T. K. ., & de Melo, T. (2020). Aplicação de técnica de imageamento térmico na determinação do número de Nusselt em uma placa plana aquecida. Revista Interdisciplinar De Pesquisa Em Engenharia, 5(2), 18–26. https://doi.org/10.26512/ripe.v5i2.28661

Issue

Vol. 5 No. 2 (2019): Revista Interdisciplinar de Pesquisa em Engenharia

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