http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Numerical modeling of flow and heat transfer in shell-and-tube heat exchangers
xxi, 210 leaves : illustrations ; 28 cm.
This dissertation describes a three-dimensional numerical
model for simulation of turbulent flow and heat transfer
inside shell-and-tube heat exchangers. The simulation is
based on a distributed resistance method that uses a modified
k-E turbulence model. It is assumed that all shellside fluid
within a computational cell has the same velocity and
temperature. Volume porosities and surface permeabilities
account for tubes, nozzles, and an arbitrary arrangement of
baffles. Sub-models are described for shellside pressure
drop, turbulence generation and dissipation by tubes, baffle-
shell and baffle-tube leakage, shellside and tubeside heat
transfer. These submodels use parameters that have not been
altered from their published values. Geometry generators are
outlined for tubes, baffles, and nozzles. The numerical
model is validated by comparison with standard benchmarks and
with experimental data for shell-and-tube heat exchangers
from the University of Delaware (Bell, 1963) and Argonne
National Labs (Halle et al., 1984). Good agreement (relative
error in overall pressure drop is less than 10% and relative
error in temperature differences is less than 15%) is
obtained between the computations and experiments. All
validations were performed for E type shells. J, F, and H
shells can be handled, but were not validated. The model can
represent single segmental baffles of any baffle cut and
baffle spacing. Double and triple segmental baffles, and
disk and donut baffles are not represented in the model.
Currently plain tubes in a staggered or inline configuration
can be represented by the numerical model. Finned tubes are
not modeled. It is assumed that the tubes are clean (no
fouling). Single tube pass parallel flow or counter flow
arrangements and a U tube bundle are modeled. Multi-tube
pass arrangement with mixing at the end of a tube pass is not
modeled. Further work needs to be done to represent
impingement plates. Since all flow calculations performed
were in the turbulent regime, effect of property variation on
pressure drop and heat transfer was not considered. After
validation, the numerical model is used to analyze three
dimensional flow, pressure, temperature, and turbulence
fields, within shell-and-tube heat exchangers. The computed
flow and turbulence fields show a reasonable behavior.
"Major Subject: Mechanical Engineering".
Issued also on microfiche from University Microfilms Inc.
Includes bibliographical references: pages 186-194.