A Numerical Study on Heat Transfer in Laminar Pulsed Slot Jets Impinging on a Surface

Authors: D. Kim

Abstract:

Numerical simulations are performed for laminar continuous and pulsed jets impinging on a surface in order to investigate the effects of pulsing frequency on the heat transfer characteristics. The time-averaged Nusselt number of pulsed jets is larger in the impinging jet region as compared to the continuous jet, while it is smaller in the outer wall jet region. At the stagnation point, the mean and RMS Nusselt numbers become larger and smaller, respectively, as the pulsing frequency increases. Unsteady behaviors of vortical fluid motions and temperature field are also investigated to understand the underlying mechanisms of heat transfer enhancement.

Keywords: Pulsed slot jet, impingement, pulsing frequency, heat transfer enhancement.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1060128

References:

[1] V. A. Chiriac, and A. Ortega, "A numerical study of the unsteady flow and heat transfer in a transitional confined slot jet impinging on an isothermal surface," Int. J. Heat Mass Tran., vol. 45, 2002, pp. 1237-1248.
[2] H. G. Lee, H. S. Yoon, and M. Y. Ha, "A numerical investigation on the fluid flow and heat transfer in the confined impinging slot jet in the low Reynolds number region for different channel heights," Int. J. Heat Mass Tran., vol. 51, 2008, pp. 4055-4068.
[3] H. J. Poh, K. Kumar, and A. S. Mujumdar, "Heat transfer from a pulsed laminar impinging jet," Int. Commun. Heat Mass, vol. 32, 2005, pp. 1317-1324.
[4] R. C. Behera, P. Dutta, and K. Srinivasan, "Numerical study of interrupted impinging jets for cooling of electronics," IEEE T. Compon. Pack. T., vol. 30, 2007, pp. 275-284.
[5] P. Xu, B. Yu, S. Qiu, H. J. Poh, and A. S. Mujumdar, "Turbulent impinging jet heat transfer enhancement due to intermittent pulsation," Int. J. Therm. Sci., vol. 49, 2010, pp. 1247-1252.
[6] R. Sau, and K. Mahesh, "Optimization of pulsed jets in crossflow," J. Fluid Mech., vol. 653, 2010, pp. 365-390.