Doctoral Dissertations

Abstract

"The effect of knurling a nucleate boiling heat transfer surface was studied. The knurling utilized produced regular, four-sided, adjacent pyramids with an apex angle of 90 degrees. Four knurling densities were used ranging from 416 to 2591 pyramids per square inch. The transfer surface was gold-plated copper and the heaters used were electrically heated, ten-inch long, horizontal cylinders of one-inch diameter. The liquid boiled was normal pentane at its saturation temperature and a pressure of 760 millimeters mercury.

For some of the knurled surfaces the temperature difference required to produce a given heat flux was found to be less than half that required for an unknurled control surface. For all of the knurled surfaces, values of the heat flux 20 per cent higher than burnout for the control surface were measured, and experimental indications suggest burnout may lie considerably higher. At low heat fluxes, where visual bubble observations could be made, bubble growth was seen to occur only at the corners of the bases of the pyramids. The experimental results can be represented by the form:: Q/n = (3.67-0.738D)ΔT1.88 where Q/n is the rate of heat transferred per pyramid [Btu/(hr)(pyramid)], D is the pyramid density [(pyramids/ft2) X 10-5], and ΔT is the temperature difference (F°)"--Abstract, leaf ii.

Advisor(s)

Park, Efton

Committee Member(s)

Strunk, Mailand R., 1919-2008
Flanigan, V. J.
Crosser, Orrin K.
Johnson, James W., 1930-2002

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Sponsor(s)

University of Missouri--Rolla. Department of Chemical Engineering

Publisher

University of Missouri--Rolla

Publication Date

1971

Pagination

vi, 65 pages

Note about bibliography

Includes bibliographical references (pages 50-53).

Rights

© 1971 Jerry James Carr, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Nucleate boiling
Heat -- Transmission
Heat flux

Thesis Number

T 4500

Print OCLC #

6855044

Electronic OCLC #

904548689

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