Geometric design of a mass transfer sensor for indoor environments using computational fluid dynamics

Author

Anjana Srirama

Abstract

“Air movement and mixing can control the transport of surface-reactive pollutants from bulk air to surfaces. To further understand pollutant transport, the efficacy of measuring mass-transfer coefficients (MTC) utilizing sublimation or evaporation from a coated microbalance sensor was evaluated. For practical utility, this sensor must project from the wall surface. Therefore, the broad goal of this research is to recommend a design for the sensor enclosure that minimizes the influence of enclosure shape on the measurement itself. Analyses were performed for enclosures with rectangular, parabolic and other cross-sections. A computational fluid dynamics package was used to determine the shear stress and the heat-transfer coefficient for the enclosure and for the wall with no enclosure. The corresponding mass transfer coefficient values were estimated using a transport analogy suggested by Chilton and Colburn. The result from the parabolic enclosure simulation deviated by about 6-8% from the flat wall value for 0.1m s^-1 mean air velocity while the deviation for the results from rectangular enclosure was 3-8%. These simulations led us to the conclusion that the parabolic enclosure experiences the smallest range of deviation over a variety of environmental conditions. We also compared the “whole-wall” mean value of the MTC with the results from a parabolic enclosure where a 20 cm and 100 cm diameter section is coated. The mean MTC for a flat wall deviates by about 140% and 40% respectively for the 20 cm and 100 cm diameter coatings. The simulated MTC values for the parabolic enclosure at a typical indoor velocity of 0.1 m s^-1 was found to be around 0.05 cm s^-1 which is in good agreement with the literature central value of 0.04 cm s^-1“--Abstract, page iii.

Advisor(s)

Morrison, Glenn

Committee Member(s)

Mendoza, Cesar
Isaac, Kakkattukuzhy M.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Environmental Engineering

Publisher

University of Missouri--Rolla

Publication Date

Spring 2005

Pagination

x, 57 pages

Note about bibliography

Includes bibliographical references (pages 55-56).

Rights

© 2005 Anjana Srirama, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

FLUENT (Computer file)
Indoor air pollution -- Analysis
Hazardous substances -- Analysis
Fluid dynamics -- Data processing
Mass transfer -- Mathematical models

Thesis Number

T 8755

Print OCLC #

63107857

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Recommended Citation

Srirama, Anjana, "Geometric design of a mass transfer sensor for indoor environments using computational fluid dynamics" (2005). Masters Theses. 5814.
https://scholarsmine.mst.edu/masters_theses/5814