Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 36 for “"pumping power"”.
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Optimization study for forced-convective cooling of an augmented printed-circuit-board surface with minimum pumping power
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.
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Air flow in a high aspect ratio heat sink
… reductions in thermal resistance and required pumping power are necessary. This research covers the development of a novel type of air-cooled heat sink, in particular the air flow through such a heat sink. The research is carried out through theory, computation, and experiment. A …
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Thermal Management with Supercritical Carbon Dioxide under Extreme Applications
… in thermal system design is minimizing the power required to operate cooling systems while maintaining effective heat removal. Traditional cooling systems utilize single-phase fluids where the heat transfer mechanisms are well understood. To meet a variety of cooling demands, a range of …
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Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes
… for the same Reynolds numbers. Data for required pumping power versus resultant Nusselt number were collected which showed four distinct operating regions for these devices spanning the low Reynolds number, steady flow region through the self-sustained oscillating flow region. Based on the data, …
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Thermo-Hydraulic Performance of Partially Blocked Metal-Foam Channels
… is the attendant higher pressure drop or pumping power penalty. This thesis was undertaken to investigate whether channels partially filled with metal foams can reduce the required pumping power with a minimal loss in thermal performance. The thermo-hydraulic (T-H) performance factor …
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The effect of hydrogen on the 585.3-nm helium-neon nuclear-pumped laser
… mixture at 585.3 nm feature the lowest threshold power density ever reported for visible nuclear-pumped, e-pumped and heavy ion beam-pumped lasers. The threshold neutron flux for the above transition was $1.5 \times 10\sp{13}$ n/(cm$\sp2$-sec), corresponding to threshold pumping power density 43 …
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Linear-cavity tunable fibre lasers employing an Opto-VLSI processor and a MEMS-based device
… noise spikes caused by the high optical pumping power. Experimental results show that by optimising a length of the SA a single wavelength, high power laser signal can be achieved. In addition, we experimentally demonstrate that the performance of the proposed linear-cavity tunable fibre …
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Experimental Investigation of Dimples as a Heat Transfer Enhancement Feature in Narrow Diverging and Converging Channels
… transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient …
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Thermorheological properties of nanostructured dispersions
… low, so as not to appreciably increase the pumping power needed to employ these fluids in "real world" applications. To this end, the theological and thermal properties of twenty-six different nanostructured dispersions were examined. In terms of rheometry, both steady flow and creep tests …
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Performance Evaluation of the Three Dimensional Woven Copper Matrix as Heat Exchanger
… found that the mesh system is efficient at low pumping power.
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Examination of the conversion of the U.S. submarine fleet from highly enriched uranium to low enriched uranium
… ratio require a significant increase in pumping power. LEU designs that require increases in weight or size of the reactor compartment are not outright infeasible, and alterations to the reactor compartment might provide a necessary recovery of weight and volume. The concept of LEU …
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Thermodynamic analysis of single-screw oil-flooded refrigerant compressors
… a control volume approach. The mechanisms for power input to the oil are presented and three of these mechanisms, oil shear, oil displacement, and external oil pumping, are dealt with analytically. The computer model, the most comprehensive model developed, gave detailed thermodynamic …
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Design Theories for Compact, Low-energy, Clog-resistant Drip Irrigation Emitters
… – high raw material-driven equipment costs, high pumping power costs associated with pressurizing all emitters in the field to their activation pressure, and gradual loss of reliability due to clogging. Compact, low-pressure, clog-resistant emitters can address these challenges, but to design …
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Natural convection of molten salt in laterally heated and top cooled vertical cylinders
… reactor technology with higher efficiency, lower pumping power and increased power density. Due to the lower operating pressures, high heat capacities, and the ability to transfer heat through natural circulation, they are especially suitable for passive safety. Unlike the common reactor designs …
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Surface self-compensated hydrostatic bearings
… performance (load verses deflection, flow rate, pumping power). The novel design that is tested uses a set of auxiliary restricting surfaces on a profile rail and form fitting truck that make an acute angle relative to each load bearing pocket they supply, thus allowing the truck to be machined …
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An Exploration of the Effect of Temperature on Different Alloys in a Supercritical Carbon Dioxide Environment
… SCO₂ allows for higher efficiencies, reduced pumping power, lower plant temperature, and more compactness compared to the other gas coolants currently being examined. However, limited corrosion data currently exists for materials that are potential pressure boundary candidates under high …
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Experimental Study of Meniscus Thin-Film Evaporation in a Horizontal-Tube, Falling-Film Heat Exchanger, Focusing on Dynamic Contact Angle Variation of an Advancing Meniscus
… heat transfer by exploiting the capillary pumping of the porous matrix, which worked to passively spread the solution fluid across the entire tube surface. The thin film created in the many menisci in the porous layer worked to further enhance evaporation due to the lowering thermal …
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Optimization of the thermal-hydraulic performance of the helium-cooled modular divertor with multiple jets
… HEMJ can accommodate 10 MW/m^2 while keeping the pumping power requirements within specified limits. The simpler HEMJ variant can accommodate 8 MW/m^2 under the same conditions, which could simplify manufacturing and reduce fabrication costs for O(10^6) modules.
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On the feasibility of generating and storing winter ice to meet water demands in the summer
… such an operation so as to minimize the required pumping power. Insulation techniques to preserve the ice for the summer are also outlined. Economic comparison with other alternatives for alleviation of water shortages such as water desalination was also made. Environmental evaluations consider …
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Convection and Flow Boiling in Microgaps and Porous Foam Coolers
… of volumetric heat transfer rate and required pumping power. The single-phase experimental results were in good agreement (within 10% error) with classical correlation of single-phase heat transfer coefficient and pressure drop in micro single gap channel with heat transfer coefficients as high …
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