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Full-Text Articles in Mechanical Engineering
The Spectral Conforming Model And Its Applications, Jaeho Shim
The Spectral Conforming Model And Its Applications, Jaeho Shim
LSU Doctoral Dissertations
It has been observed that finite element or finite difference model of order can approximate with fair accuracy less than one-third of the eigenvalues of the underlying continuous system corresponding to the low spectrum. The new discrete model, namely the spectral conforming model, is developed to predict the eigenvalues of continuous systems in both the low and high spectra. The spectral conforming models are developed using an inverse vibration method. The classical vibration problem is the direct method. In the direct approach, the characteristic behaviors of the system, i.e. frequency response, natural frequency, and steady state response are analyzed and …
Replication Of Metal-Based High-Aspect Microscale Structures By High Temperature Micromolding, Dongmei Cao
Replication Of Metal-Based High-Aspect Microscale Structures By High Temperature Micromolding, Dongmei Cao
LSU Doctoral Dissertations
In microsystem technology a large range of materials will be available only after the necessary microfabrication technologies have been developed or adapted. More than a decade ago, the existing microfabrication technologies were restricted to structuring and shaping techniques producing three-dimensional microstructures out of silicon, mostly unfilled plastics or a few pure metals or binary alloys. However, the choice of materials for microcomponents is determined by the function and conditions of use of microsystems. Some microdevices can only work well when made of specific metal components. To meet this need, several microfabrication techniques have been developed, such as second electroforming of …
Numerical Methods For The Unsteady Incompressible Navier-Stokes Equations And Their Application To The Direct Numerical Simulation Of Turbulent Flows, Frank Herbert Muldoon
Numerical Methods For The Unsteady Incompressible Navier-Stokes Equations And Their Application To The Direct Numerical Simulation Of Turbulent Flows, Frank Herbert Muldoon
LSU Doctoral Dissertations
Two new methods for the efficient parallel computation of the unsteady incompressible Navier-Stokes equations are presented. Such efficient methods are desired for large scale parallel computations of unsteady turbulent flows such as Direct Numerical Simulations (DNS). The performance of the new methods has a distinct advantage over the artificial compressibility method, in that the methods exhibit robust convergence for a variety of flow problems without extensive need for tuning computational parameters. These methods and others have been implemented in a computer program designed for massively parallel computer architectures, written by the author and used to obtain all results in this …
Turbine Blade Tip Cooling And Heat Transfer, Hasan Nasir
Turbine Blade Tip Cooling And Heat Transfer, Hasan Nasir
LSU Doctoral Dissertations
Turbine blade tip leakage flow from blade pressure side to suction side over the tip surface increases the thermal loading to the blade tip, leading to a high local temperature and thus, is considered one of the primary sources of blade failure. Leakage flow can be reduced by using a recessed or squealer tip blade or by cooling the blade tip to incorporate film cooling. The performance of different recessed tip geometries were investigated and compared with plane tip performance. A transient liquid crystal technique was employed to measure detailed heat transfer coefficient distributions. Coolant injection from holes located on …