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Showing 1 to 20 of 40 for “"Tube wall"”.
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Effects of Louver Length and Vortex Generators to Augment Tube Wall Heat Transfer in Louvered Fin Heat Exchangers
… the effect of louver length on pressure drop and tube wall heat transfer, which is the primary heat transfer surface in the heat exchanger. The second is to augment tube wall heat transfer with the use of delta winglets placed on the fins near the tube wall. These studies were completed on a 20X …
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The use of coherent anti-Stokes Raman Spectroscopy as a diagnostic technique for studying the hydrogenation of carbon moxide in a tube-wall reactor
… bed type, but there is an interest in using tube-wall reactors in order to reduce the large pressure drops normally associated with fixed bed reactors. Coherent Anti-Stokes Raman Spectroscopy (CARS) is a relatively new laser-based spectroscopic technique which may be used to obtain the …
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Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers
… govern air side heat transfer is required. The tube wall heat transfer results presented in this paper were obtained both experimentally and computationally for a typical compact heat exchanger design. Both isothermal and constant heat flux tube walls were studied. For the experimental …
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Practical Applications of Delta Winglets in Compact Heat Exchangers with Louvered Fins
… vehicle designs. Air-side resistance on the tube wall and louvered fin surfaces comprises over 85% of total resistance to heat transfer in louvered fin heat exchangers. The tube wall surface is considered the primary surface for heat transfer, where the temperature between the working fluid …
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Strain-induced self-rolled-up semiconductor micro/nanotubes: Fabrication and characterization
Strain-induced self-rolled-up semiconductor nanotubes are a new type of building block for three-dimensional architectures. Semiconductor nanotubes (SNTs) take advantage of the lattice mismatch between different layers and are formed when the strained semiconductor layers are released from the …
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The rheology and flow behaviour of high concentration mineral slurries
… are investigated using a modified Balance Beam Tube Viscometer. The viscometer is capable of producing reliable data using a computer based data acquisition system and three different tube diameters. The aim of this research is to determine the rheology of backfill tailings in order to predict …
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Analysis of power balance in a helicon plasma source
… thrust performance. The loses to the quartz tube wall was substantially higher than the loses at the metal bellow region and the loses due to ionization and excitation. Future improvements in Langmuir probe design to characterize the plasma and the feasible changes to the experimental setup …
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An experimental investigation of instability in turbulent-flow freezing
… internal flow due to external cooling of the tube wall was conducted. A region of unstable freezing behavior was located and bounded in terms of initial Reynolds number and a nondimensional temperature parameter for the given system. This region was observed over the span of Reynolds numbers …
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Heat transfer coefficients between condensing organic vapors and a vertical copper tube
… condensed on the outside of a three foot copper tube placed in a vertical position. Water velocities through the tube were varied from 0.18 to 1.38 feet per second. Mass velocities of from 4 to 50 pounds per hour of' vapor were condensed on the tube. The copper tube employed was of 18-gauge metal …
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Condensing heat transfer within horizontal tubes
… of a vapor condensing within a horizontal tube. Condensing heat transfer coefficients for propane were measured over a wide range of conditions. The data would not correlate using the existing equations for condensation. A new mechanism was postulated of a laminar condensate film, forming …
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Tube-forming device design for the creation of cell-integrated alginate tubes
… capable of forming cell-populated alginate tubes either by seeding cells within its lumen, or integrating cells within the tube walls. The applications of an alginate tube are as diverse as applications of alginate beads, and could be used with many types of cells for many different purposes …
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STUDY OF AIR BUBBLE INJECTION INTO LAMINAR AND TURBULENT WATER FLOW THROUGH AN ANNULAR TEST SECTION
… indicate that air bubble injection from an inner tube into the liquid stream causes large increase in the streamwise and spanwise velocity fluctuations near the inner tube wall for both laminar and turbulent liquid flows. The bubble size, shape, and trajectory data were also obtained for both …
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Characterization of heat transfer rates in supercritical ethanol for micro-rocket engine regenerative cooling
… resulted from the use of small diameter circular tubes fed by a pressurized fuel supply. The test sections consisted of resistively heated stainless steel hypodennic tubes ~4mm in length with an inside diameter of ~95[mu] Test conditions were such that most of the physical parameters that are …
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Laminar heat transfer to non-Newtonian fluids in pipes with abrupt changes in diameter
… flow indices "n" ranging from 0.39 to 0.9.The tube configurations were a 3.3 :1 sudden convergence, and a 1: 3.3 sudden divergence.The condition of a prescribed uniform wall heat flux was considered, with both upstream and downstream tube sections heated. Radial temperature traverses were also …
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Connections to concrete-filled steel tubes
… to study connections to concrete-filled steel tubes. This research focused on the connection to circular steel tubes, because this shape presents more detailing difficulties compared to the square counterpart. To accomplish the goals of this study, the research was divided into three phases: …
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Experimental Study of Capillary-Assisted Solution Wetting And Heat Transfer Using A Micro-Scale, Porous-Layer Coating On Horizontal-Tube, Falling-Film Heat Exchanger
The horizontal-tube falling-film heat exchangers have many different applications ranging from large refrigeration systems to desalination due to their high heat transfer coefficients with low liquid inventory. However, the problem of partial solution wetting severely deteriorates the heat transfer …
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Heat transfer and visualization in large flattened-tube condensers with variable inclination
… of steam in a large, inclined, finned tube is presented. This study extends previous work in the field on inclined, convective condensation in small, round tubes to large, non-circular tubes with low inlet mass flux of vapor. The steel condenser tube in this study was designed for use …
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An investigation of the effect of entrained oil on the heat transfer rate of a refrigerant evaporator
… to reduce heat transfer across the evaporator tube wall. At 25°F suction temperature, the reduction in the heat transferred was 5% with an oil concentration of 0.84% by volume compared to the refrigerant with an oil concentration of 0.063%. At 30°F suction temperature the reduction in the heat …
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The effects of wall inertia and axial bending on instabilities in flow through an elastic-walled tube
… parameter regimes, steady flow through flexible tubes is unstable to self-excited oscillations. Whittaker et al. (2010, Proc. Roy. Soc. A 466) solved an asymptotic model for the onset of self-excited oscillations in a long, thin-walled,flexible tube clamped between two rigid tubes, with a large …
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