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Vortex Wake And Exhaust Plume Interaction, Including Ground Effect, Ihab Gaber Adam
Vortex Wake And Exhaust Plume Interaction, Including Ground Effect, Ihab Gaber Adam
Mechanical & Aerospace Engineering Theses & Dissertations
Computational modeling and studies of the near-field wake-vortex turbulent flows, far-field turbulent wake-vortex/exhaust-plume interaction for subsonic and High Speed Civil Transport (HSCT) airplane, and wake-vortex/exhaust-plume interaction with the ground are carried out. The three-dimensional, compressible Reynolds-Averaged Navier-Stokes (RANS) equations are solved using the implicit, upwind, Roe-flux-differencing, finite-volume scheme. The turbulence models of Baldwin and Lomax, one-equation model of Spalart and Allmaras and two-equation shear stress transport model of Menter are implemented with the RANS solver for turbulent-flow modeling.
For the near-field study, computations are carried out on a fine grid for a rectangular wing with a NACA-0012 airfoil section and …
Material Evaluation By Pulsed Diode Laser Optoacoustics, Xiaodong Xu
Material Evaluation By Pulsed Diode Laser Optoacoustics, Xiaodong Xu
Electrical & Computer Engineering Theses & Dissertations
Pulsed diode laser optoacoustic diagnostics were carried out to characterize solid sample materials. The apparatus developed is compact, portable, cost-effective and therefore very promising for both industrial as well as laboratory applications. To our knowledge, this is the first time that optoacoustic characterization and measurement have been performed with a diode laser. The method was successfully applied to measure the thickness of a multilayer structure non-intrusively. Internal cracks of the material were detected by this technique.
A theory for optoacoustic signal generation, propagation and detection is given. A numerical analysis technique is developed to solve for the expected signal. In …