Date of Award

Winter 2014

Degree Type

Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

First Advisor

Balachandar, Ramaswami

Second Advisor

Barron, Ronald M.

Keywords

Applied sciences, Heat transfer, Rotation, Spray cooling

Rights

CC BY-NC-ND 4.0

Abstract

The impingement of sprays onto dry and wet walls and the associated heat transfer occurs in many engineering applications. These applications include internal combustion engines, gas turbines, spray drying, spray coating and spray cooling. The fluid dynamics and heat transfer characteristics of liquid films created by spray impingement are very complex and determining the underlying physics requires fundamental studies. In this study, an efficient and practical approach is devised for tackling many aspects of the spray cooling process. The computational fluid dynamics (CFD) methodology used here includes numerous droplets and it is designed to predict the spray-wall impact outcome based on reliable correlations. Even though it is not an exact representation of the interaction between the spray and the liquid layer due to computational considerations, it provides an acceptable picture of the transport phenomena. The STAR-CCM+ CFD code has been used to solve continuity, momentum, and energy equations coupled with a Lagrangian-Eulerian solver capable of simulating droplets as well as thin fluid film. The model is validated against relevant experimental data available in the literature and good agreement is observed for heat transfer coefficient (HTC) values for cases involving spray impact and fluid film formation over a flat solid surface. The effect of mass flux and spray Reynolds number on the spray behaviour has been studied. The model is extended to predict the cooling performance of sealed cans containing hot liquids when the cans are cooled by the impingement of spray formed from a cold liquid. The CFD results are compared with field data obtained at Heinz Canada, Leamington, ON. The effect of the can rotational speed on the cool-down behaviour is investigated. The results show that there is an optimum rotational speed beyond which the heat transfer enhancement will not be as significant. This research is the first study which solves the transport phenomena of fluid and heat outside, through and inside a sealed solid can containing a hot liquid while being cooled by the spray of a cold liquid.

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