Numerical simulation of jet impingement cooling on a smooth concave surface

Md Seri, Suzairin (2009) Numerical simulation of jet impingement cooling on a smooth concave surface. Masters thesis, Universiti Tun Hussein Onn Malaysia.

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Abstract

Jet impingement has been widely used as a means of heat removal because of its advantages in effective removal of locally concentrated heat and easy adjustment to the location where cooling is needed. Typical applications are paper drying, cooling of electronic chips, annealing of glass and elimination of excessive thermal load near the leading edge of gas turbine blade inner surface. More studies of jet impingement cooling are reported on flat surfaces than on concave and convex surfaces. For the flows on concave surface, the centripetal force due to the curvature makes the flow unstable and produces Taylor-Gortler vortices. Such vortices are known to enhance momentum and energy transfer and thereby heat transfer rate on the surface. The present study involves a 2-dimensional simulation of homogeneous air jet impinging normally onto a smooth concave surface from a single slot nozzle by means of the Computational Fluid Dynamics software FLUENT. The effect of Reynolds num ber and nozzle-to-target spacing on the velocity profile and the local Nusselt number are studied by means of the Reynolds stress model. The predicted results are validated against the experimental data ofChoi et al. (2000). The optimum conditions of operation correspond to the ratio of heat transferred to the pumping power. The value of the optimum nozzle-to-targct distance has been identified. It is observed that the optimum paramcter is dependent on the flow Reynolds number. Correlations of mean Nusselt number, nondimensional pressure drop and mean temperature are obtained as they can assist in the design of equipment for relevant applications with relative ease, especially in view of the enhanced heat transfer encountered in the concave surface jet impingement. The performance of the k-£ turbulence model is also evaluated and compared with the Reynolds stress model used.

Item Type:Thesis (Masters)
Subjects:T Technology > T Technology (General)
ID Code:983
Deposited By:M.Iqbal Zainal A
Deposited On:24 May 2011 09:09
Last Modified:24 May 2011 09:09

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