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Development of a novel film cooling hole geometrySargison, Jane Elizabeth January 2001 (has links)
No description available.
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Effects of wake and shock passing on the heat transfer to a film cooled transonic turbine bladeRigby, M. J. January 1990 (has links)
No description available.
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Heat transfer on nozzle guide vane end wallsHarvey, Neil William January 1991 (has links)
No description available.
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Comparison of CFD Simulation and Experimental Data for Heating and Cooling Low N Packed Beds of Spherical ParticlesMorgan, Ashley T 01 May 2014 (has links)
This study compared experimental and Computational Fluid Dynamics (CFD) results for heating and cooling in a packed bed (N=5.33). The experimental data was compared between heating and cooling, and was also used to validate the CFD model. The validated models were used to compare theoretical heat transfer parameters. For the experiments, it was found that the effective thermal conductivity was comparable for heating and cooling, and the wall Nusselt number for heating was higher. For the CFD results, it was found that both the wall Nusselt number and effective thermal conductivity were comparable for heating and cooling. The wall Nusselt number was slightly higher for cooling, however this difference decreased as the Reynolds number increased.
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Comparison of CFD Simulation and Experimental Data for Heating and Cooling Low N Packed Beds of Spherical ParticlesMorgan, Ashley T 01 May 2014 (has links)
This study compared experimental and Computational Fluid Dynamics (CFD) results for heating and cooling in a packed bed (N=5.33). The experimental data was compared between heating and cooling, and was also used to validate the CFD model. The validated models were used to compare theoretical heat transfer parameters. For the experiments, it was found that the effective thermal conductivity was comparable for heating and cooling, and the wall Nusselt number for heating was higher. For the CFD results, it was found that both the wall Nusselt number and effective thermal conductivity were comparable for heating and cooling. The wall Nusselt number was slightly higher for cooling, however this difference decreased as the Reynolds number increased.
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Surface tension effects in condensation heat transfer : condensation on wire-wrapped tubes and Marangoni condensation of mixturesMurase, Takahiro January 2006 (has links)
Enhancement of condensation heat transfer by wrapping of fine WIres on a condenser tube and Marangoni condensation of binary mixtures have been studied. For wire-wrapped tubes enhancement is due to modification of the profile of the condensate surface which leads to axially-directed pressure gradients and local thinning of the condensate film. Approximate theories do not agree well with limited available data prior to the present work. A systematic experimental investigation has been conducted using three fluids with widely different properties. Five wire diameters and a range of winding pitch have been used. Maximum heat-transfer enhancement ratios of 3.7, 2.2 and 2.3 for R-I13, ethylene glycol and steam respectively were obtained. The effect of inundation for steam condensation on wire-wrapped tubes has also been investigated. Extensive data exist for Marangoni condensation of steam-ethanol mixtures on small plane ve.rtical surfaces. Here the practically more relevant case C?f a horizontal tube has been studied. Apparent differences between the vertical plate and horizontal tube data are shown to be due to circumferential variation of tube surface temperature. Enhancement ratios up to around 3.7 have been obtained with as little as 0.05% mass fraction of ethanol in the boiler feed. For wire-wrapped tube and Marangoni condensation, a copper condenser tube (outside diameter 12.2 mm) fitted with four embedded wall thermocouples was cooled internally by water using a wide range of flow rates. The coolant temperature rise was measured to within 0.01 K using a ten-junction thermopile while the coolant temperature rise ranges were 0.11 to 0.77 K, 0.89 to 9.28 K and 1.00 to 6.98 K for the wire-wrap tests with R-I13, ethylene glycol and steam respectively and 1.24 to 29.1 K for Marangoni condensation. The effect on the boiler performance for water-ethanol mixtures has also been investigated.
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Heat Transfer in Smooth and Ribbed Rectangular Two-Pass Channels with a Developing Flow Entrance at High Rotation NumbersHuh, Michael 16 January 2010 (has links)
Cooling channels with a developing flow entrance condition and aspect ratios of
1:4 and 2:1 were studied. The range of the rotation number and buoyancy parameter for
the selected AR channels was extended. The maximum Ro and Bo for the 1:4 channel
was 0.67 and 1.9, respectively. For the 2:1 channel, these values were 0.45 and 0.85,
respectively.
The effect of rib spacing and rib height on heat transfer in the 1:4 channel is
investigated. Three rib spacing configurations were considered: P/e=2.5, 5, 10 with a
constant e/Dh ratio of 0.078. To investigate the effect of rib height, a rib configuration
with an e/Dh ratio of 0.156 and P/e ratio of 10 was considered. For the 2:1 channel, a
smooth channel surface condition was studied. For each channel aspect ratio and surface
condition, five Reynolds numbers were studied up to 40K. At each Re, five rotational
speeds are considered up to 400 rpm.
The results of this research work indicate that rotation can cause a significant
increase in heat transfer on the first pass trailing surface of both aspect ratio channels. The leading surface in ribbed channels has shown a dramatic decrease in heat transfer
with rotation in the first pass. Reductions in heat transfer by as much as 50% were
observed. In the second pass, the leading and trailing surfaces with ribs showed very
similar effects of rotation. Also, the effect of rotation seems to vary with the rib spacing.
The strength of rotation showed to be greater in the tight rib spacing of P/e=2.5. The rib
height in the 1:4 channel had minimal impact due to the large distance between the
leading and trailing surfaces. The tip cap heat transfer for both channels showed large
increases with rotation. This is very beneficial since tip cooling is an important part of
maintaining the life a turbine blade. Finally, the buoyancy parameter proved to be very
useful in predicting heat transfer in rotating conditions. The correlations developed
showed very acceptable accuracy when compared to the experimental data.
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Characterization of Product Quality Attributes and Thermal Properties of Potato Chips during Vacuum FryingYagua Olivares, Carla Veronica 2010 August 1900 (has links)
Vacuum frying is an alternative processing method for producing high quality
snacks with the advantages of lower processing temperature, enhanced organoleptic
quality, and reduced acrylamide content. Vacuum frying (1.33 kPa), with the aid of a deoiling
mechanism, was used to produce low-fat potato chips.
The kinetics of oil absorption and oil distribution in the potato chips (total,
internal, and surface oil content) was studied so that effectiveness of the de-oiling
system could be established. An analysis of product quality attributes (PQA) such as
moisture content, oil content, microstructure, diameter shrinkage, and thickness
expansion, as well as, bulk density, true density, and porosity of chips fried at different
temperatures (120, 130, and 140 degrees C) was performed in order to evaluate the effect of
process temperature on the product. Moreover, heat capacity of the chips and convective
heat transfer coefficient at the oil-chip interface were determined for the same
temperature range.
The final oil content of the potato chips was 0.072±0.004, 0.062±0.003, and
0.059±0.003 g/g solid for frying temperatures of 120, 130, and 140 degrees C, respectively.
These values are lower (80-85 percent less) than those found in traditionally-fried potato chip
which indicates that the de-oiling mechanism is crucial in vacuum frying processing. A
significant difference (P<0.05) was observed in oil content and oil distribution within
temperatures. It was found that the rate of change in PQAs is greatly affected by
temperature; however, the final values of moisture content, bulk density, true density,
porosity, diameter shrinkage, and thickness expansion were not affected by temperature.
During vacuum frying, the specific heat of potato chips decreased with time as
water decreases. The convective heat transfer coefficient changed considerably as frying
progresses; moreover, it increased with temperature reaching a maximum between 2,200
and 2,650 W/m2K depending on frying temperature.
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Turbulent heat transfer in a trapezoidal channel with transverse and v-shaped ribs on two opposite wallsSubramanian, Karthik 12 April 2006 (has links)
This study investigates the turbulent heat transfer and friction in a trapezoidal
channel with opposite walls roughened with transverse and v-shaped ribs. The
roughened channel depicts the internal cooling passage of an aerofoil near the trailing
edge. The various configurations investigated for this study are smooth channel, channel
with 90° transverse ribs and channel with v-shaped ribs angled at 45°. The pitch-toheight
ratio (P/e), rib height-to-hydraulic diameter ratio (e/Dh) and the aspect ratio (W/e)
were maintained at 12, 0.1906 and 1, respectively. The configuration was tested for
Reynolds number ranging from 7,000 to 40,000. The 45° rib was found to produce the
maximum heat transfer and minimum pressure loss.
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Temperature dependent properties and microvoid in thermal laggingChiu, Kwong-Shing Kevin, January 1999 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 182-186). Also available on the Internet.
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