An analytical model of the radiative contribution to the
total heat transfer between a large-particle (greater
than 1 mm) gas-fluidized bed and an immersed horizontal
tube is discussed. The model is applied to the case of a
bubbling bed and the emulsion phase contribution is obtained from a detailed analysis...
A steady gas convection model of heat transfer to a horizontal
cylinder immersed in a gas fluidized bed is presented. Contributions due to flow within
attached bubbles as well as the interstitial voids are
included. The interstitial flow is approximated as flow within a series
of double cusped channels and...
Heat transfer from a vertical flat plate in an infinite pool of
mercury was investigated. Velocity profiles were measured with a
hot-film anemometer and simultaneous temperature profiles measured
with thermocouples in this low Prandtl number liquid metal. Constant
heat flux plates at Grashof numbers of 9 x 10⁸ and 4...
The heat-transfer phenomena studied in this work were
associated with pool boiling from a flat horizontal surface facing
upward with the bulk liquid at its saturation temperature. The
analysis of boiling sound and the investigation of the transition boiling
mechanism constituted the essence of the present study.
The distinctively large...
A unique channel surface enhancement technique via diffusion-bonding a layer of conductive fine wire mesh onto the heating wall was developed and used to experimentally study flow boiling enhancement in parallel microchannels. Each channel was 1000 μm wide and 510 μm high. A dielectric working fluid, HFE 7000, was used...
Heat transfer and fluid mechanical behavior of water
flowing horizontally in vertically-narrow rectangular
channels was studied in this work. Friction factor and
Nusselt number variations were determined experimentally
for four different wall heating conditions, and for aspect
ratios(height to width) of 5, 4, 3, 2, and 1. Wall
heating conditions...
Convection heat transfer was experimentally investigated
for two different geometries. One case had three horizontal
cylinders in a vertical plane placed between two vertical walls.
The second case had three horizontal cylinders in a vertical plane
with only one vertical wall. Several different cylinder center-tocenter
spacings were investigated. The wall...
Experimental data are reported for the time-averaged
local radiative and total heat transfer coefficients for
both an array of horizontal tubes as well as a single
horizontal tube immersed in a large-particle fluidized bed
at elevated temperatures. Spatial-averaged heat transfer
coefficients computed from the local values, using a simple
trapezoidal...
This thesis is concerned with the analysis of heat transfer in a tube with forced flow under conditions of an arbitrary variation of wall heat flux both axially and circumferentially. This total study is separated into two distinct problems which are presented separately. The first is the case of a...
The thermal wave technique has been explored for the use of liquid thermal conductivity measurement and flow property diagnostics in this dissertation. For liquid thermal conductivity measurements, an experimental technique based on the thermal wave approach is developed. A stainless steel strip functions as both a heating element and a...
An experimental study is described in which time-average local heat
transfer coefficients were obtained for arrays of horizontal tubes immersed
in a hot fluidized bed. Spatial-averaged heat transfer coefficients, computed
from local values, are also reported. Refractory particles with surface
mean diameters of 2.14 mm and 3.23 mm were fluidized...
Characterization of local boiling trends, in addition to the typically reported area-averaged trends, is essential for the robust design and implementation of phase change technologies to sensitive heat transfer applications such as electronics cooling. Obtaining the values of heat fluxes corresponding to locally varying surface temperatures has been a challenge...
Two problems relating to the processing of solid streams are
treated in two sections.
The first section is the study of heat transfer between an
immersed cylinder and a moving bed of solids: An instrumented heated
cylinder was placed in the flow stream of a moving bed of solids with...
In recent years, the global nuclear industry has placed a greater emphasis on passively safe reactor designs. In particular, much attention and design work has been applied to engineered systems for passive cooling of nuclear fuel, whether it be loaded in a core or stored in spent fuel pools. The...
The ever increasing requirements for heat dissipation in various thermal management applications such as computer chip cooling and high power electronics have necessitated the need for novel thermal management techniques. Thermal management using heat sinks with microscale features is amongst the prominent techniques developed over the past two decades. In...
Metal oxide nanocrystals have attracted significant interests due to their unique chemical, physical, and electrical properties which depend on their size and structure. In this study, a continuous flow microreactor system was employed to synthesize metal oxide nanocrystals in aqueous solution. Assembly of nanocrystals is considered one of the most...