Degree Type

Dissertation

Date of Award

1983

Degree Name

Doctor of Philosophy

Department

Chemical and Biological Engineering

Abstract

The objective of this research is to study theoretically the growth rate and tip radius of unconfined ice crystals along their basal plane in flowing subcooled and aqueous NaCl solutions at flow velocities above 1 cm/sec and low degrees of subcooling. The data analyzed were those of Barduhn's group from Syracuse University;A shape-preserving model was used in constructing dendritic growth models. This qualitatively explained the solute effects, namely, the tip sharpening, and enhancement in growth velocity with salt concentration with a well-defined maximum at low solute concentration. The importance of kinetics in the analysis of crystal growth was felt. A method to estimate the kinetics in ice crystals was proposed;Three fundamental theoretical models for forced convection heat and mass transfer from parabolic cylinders and paraboloids of revolution which could be used in dendritic growth are developed. They are: Oseen type rectilinear flow, Potential flow and Oseen's viscous flow approximation.

DOI

https://doi.org/10.31274/rtd-180813-5982

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Sachindra Kumar Dash

Language

en

Proquest ID

AAI8316309

File Format

application/pdf

File Size

232 pages

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