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Full-Text Articles in Mechanical Engineering

Gas Turbine Blade Tip And Near Tip Heat Transfer With Film Cooling, Gregory Kramer Jan 2011

Gas Turbine Blade Tip And Near Tip Heat Transfer With Film Cooling, Gregory Kramer

LSU Master's Theses

Gas turbine blade tips experience very high thermal loads due to high temperature combustion gases and tip leakage flows. This leads to the tip region being very susceptible to experiencing failures. To better understand these effects, experiments were performed in a suction-type low speed wind tunnel cascade to determine heat transfer coefficients and film cooling effectiveness distributions on a highly-loaded 2-D gas turbine blade model in the tip and near-tip regions. The blade shape was generated to match the pressure coefficients of the operating turbine blade design. The model featured multiple tip and pressure side film cooling holes and a …


V2o5-Wo3 Composite Films And Surface-Coated Licoo2 For Enhanced Li-Ion Intercalation Properties, Chuan Cai Jan 2011

V2o5-Wo3 Composite Films And Surface-Coated Licoo2 For Enhanced Li-Ion Intercalation Properties, Chuan Cai

LSU Master's Theses

We have investigated the enhanced Li-ion intercalation properties of two different materials, which are V2O5-WO3 composite and surface-coated LiCoO2. A simple and novel solution processing method is employed to prepare V2O5-WO3 composite films that demonstrate enhanced Li-ion intercalation properties for applications in Li-ion batteries or electrochromic displays. This solution processing method employs precursors that only contain the elements of V, W, O and H, which avoids impurity elements such as Na that has been commonly used in other solution methods (e.g. using precursors of sodium metavanadate and sodium tungstate solution). The V2O5-WO3 composite films show enhanced Li-ion intercalation properties compared …


Pool Boiling Enhancement Via Micro Ratchets, Lance Austin Brumfield Jan 2011

Pool Boiling Enhancement Via Micro Ratchets, Lance Austin Brumfield

LSU Master's Theses

Nucleate boiling is an attractive method for achieving high heat flux at low superheat temperatures. It is frequently used for industrial applications such as heat exchangers and is being considered to cool advanced central processing units (CPU) which produce heat fluxes on the order of 1 MW/m2 and are becoming increasing less efficient to cool via forced conduction of air. The issues with implementing nucleate boiling as a cooling mechanism lies in the difficulty of quantifying the complex and numerous mechanisms which control the process. A comprehensive nucleate boiling model has yet to be formulated and will required in order …


Design, Fabrication And Characterization Of A New Wind Tunnel Facility – Linear Cascade With A Wake Simulator, Jean-Philippe Junca-Laplace Jan 2011

Design, Fabrication And Characterization Of A New Wind Tunnel Facility – Linear Cascade With A Wake Simulator, Jean-Philippe Junca-Laplace

LSU Master's Theses

A new wind tunnel has been designed and constructed at the LSU Mechanical Engineering Laboratories. The objective was to design a versatile test facility, suitable for a wide range of experimental measurements on turbine blades. The future study will investigate the impact of unsteady inflow conditions on film cooling performance. More specifically, it will study how the unsteady flow due to the upstream passing wakes coming from the front row vane affects the film cooling performances on the turbine blades. The test section consists of a four passage linear cascade composed of three full blades and two shaped wall blades. …


Two-Stage Biaxial Thermomechanical Cycle Of Shape Memory Polymer Based Syntactic Foam, Abraham Michael King Jan 2011

Two-Stage Biaxial Thermomechanical Cycle Of Shape Memory Polymer Based Syntactic Foam, Abraham Michael King

LSU Master's Theses

A shape memory polymer (SMP) is a polymeric material that exhibits shape memory behavior. It can be “programmed” to take on a desired shape and “recovered” to revert back to its original shape. This ability to remember multiple shapes and switch between them with the application of a stimulus from an outside source is very desirable in certain applications. By dispersing glass microspheres in a SMP matrix, a syntactic foam is created that retains much of the shape memory capabilities but has higher strength and lower density than the pure SMP. These characteristics make this material a good candidate for …


Effect Of Piezoelectric Actuation On Curved Beams And Single Lap Joints, Calicia Johnson Jan 2011

Effect Of Piezoelectric Actuation On Curved Beams And Single Lap Joints, Calicia Johnson

LSU Master's Theses

Piezoelectric materials have seen a significant usage increase over the past decade. They have been found to be effective as either sensors or actuators in smart structure applications, which allows them to act more as an adaptive system rather than a passive system. Piezoelectric materials are very effective transducers which convert mechanical energy into electrical energy, known as the direct piezoelectric effect or they have the ability to convert electrical energy to mechanical energy, known as the converse piezoelectric effect. The absence of additional mechanical parts, its lightweight and high strength to weight ratio is what make piezoelectric materials so …


The Design And Modification Of A Sputter System For Dc Reactive Sputtering Of Alumina And Zirconia Thin Films, Diane Van Ho Jan 2011

The Design And Modification Of A Sputter System For Dc Reactive Sputtering Of Alumina And Zirconia Thin Films, Diane Van Ho

LSU Master's Theses

Yttria-stabilized zirconia (7% YSZ) is the most used material for thermal barrier coatings (TBCs) to reduce the conductive heat transfer on turbine blades, but it is not resistant to infrared radiation. In order to reduce radiation heat transfer, alternating materials, such as alumina and zirconia, can be used to fabricate multi-layer coatings in which each layer is optimized to reflect a targeted range of wavelength. This research aims to fabricate these multi-layer coatings by reactive magnetron sputtering. Reactive magnetron sputtering is the sputtering of an elemental target in the presence of a reactive gas that will react with the target …