Abstract

Boiling has for a long time been regarded as a promising option in a wide range of applications such as electronic cooling, steam generation in boiler or solar concentrators, space applications etc. In order to make boiling a more attractive option for various applications many surface enhancements have been developed to improve the heat transfer performance during boiling. Recent literature indicates that boiling performance can be significantly improved by using evaporation momentum force to control the trajectory of a bubble. This approach merits a detailed investigation into evaporation momentum force, its effect on bubble growth, bubble trajectory and heat transfer. The objective of the current work is to theoretically determine and experimentally observe the effect of evaporation momentum force on the trajectory of a bubble.

An expression for evaporation momentum pressure resulting from the evaporation momentum force experienced by a bubble is determined. The expression is incorporated into a well established bubble growth models to evaluate the effect of evaporation momentum pressure on bubble growth rate. The effect of evaporation momentum force on a bubble growing in asymmetric temperature field is then studied and the resultant trajectory is evaluated. The results are compared with experimental data of bubble trajectory subjected to an asymmetric temperature condition obtained using a high speed camera. The final results suggest that the evaporation momentum pressure in the vicinity of contact line can significantly change the bubble trajectory, and surfaces designed to exploit this effect seem to be promising for boiling enhancement.

Library of Congress Subject Headings

Bubbles--Dynamics; Evaporation; Momentum transfer; Ebullition

Publication Date

7-2014

Document Type

Thesis

Student Type

Graduate

Degree Name

Mechanical Engineering (MS)

Department, Program, or Center

Mechanical Engineering (KGCOE)

Advisor

Satish G. Kandlikar

Advisor/Committee Member

Robert J. Stevens

Advisor/Committee Member

Mario W. Gomes

Comments

Physical copy available from RIT's Wallace Library at QC161 .R34 2014

Campus

RIT – Main Campus

Plan Codes

MECE-MS

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