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Full-Text Articles in Mechanical Engineering
A Study Of Flow Separation In Transonic Flow Using Inviscid And Viscous Cfd Schemes, James Andrew Rhodes
A Study Of Flow Separation In Transonic Flow Using Inviscid And Viscous Cfd Schemes, James Andrew Rhodes
Mechanical & Aerospace Engineering Theses & Dissertations
A comparison of flow separation in transonic flows is made using various computational schemes which solve the Euler and the Navier-Stokes equations of fluid mechanics. The flows examined are computed using several simple two-dimensional configurations including a backward facing step and a bump in a channel. Comparison of the results obtained using shock fitting and flux vector splitting methods are presented and the results obtained using the Euler codes are compared to results on the same configurations using a code which solves the Navier-Stokes equations.
Topology And Grid Adaption For High-Speed Flow Computations, Jamshid Samareh Abolhassani
Topology And Grid Adaption For High-Speed Flow Computations, Jamshid Samareh Abolhassani
Mechanical & Aerospace Engineering Theses & Dissertations
This study investigates the effects of grid topology and grid adaption on numerical solutions of the Navier-Stokes equations. In the first part of this study, a general procedure is presented for computation of high-speed flow over complex three-dimensional configurations. This includes the grid generation and solution algorithm for Navier-Stokes equations in a general three-dimensional curvilinear coordinate system. The flow field is simulated on the surface of a Butler wing in a uniform stream. Results are presented for Mach number 3.5 and a Reynolds number of 2,000,000. The O-type and H-type grids have been used for this study, and the results …
The Effects Of Nonlinear Damping On The Large Deflection Response Of Structures Subjected To Random Excitation, Chunchu Bhavani Prasad
The Effects Of Nonlinear Damping On The Large Deflection Response Of Structures Subjected To Random Excitation, Chunchu Bhavani Prasad
Mechanical & Aerospace Engineering Theses & Dissertations
Effects of both nonlinear damping and large deflection stiffness are included in the theoretical analysis in an attempt to explain the experimental phenomena of aircraft panels excited at high sound pressure levels; that is the broadening of the strain response peak and the increase in modal frequency. Beams and symmetrically laminated plates subjected to acoustic excitation are considered in the analyses. The excitations are ergodic and Gaussian with zero mean. A polynomial containing both linear and nonlinear damping terms is considered as a damping model. Galerkin's method is used to derive modal equations. Direct equivalent linearization is used to solve …
Experimental Study Of Shock Wave Interference Heating On A Cylindrical Leading Edge, Allan R. Wieting
Experimental Study Of Shock Wave Interference Heating On A Cylindrical Leading Edge, Allan R. Wieting
Mechanical & Aerospace Engineering Theses & Dissertations
An experimental study of shock wave interference heating on a cylindrical leading edge representative of the cowl of a rectangular hypersonic engine inlet at Mach numbers of 6.3, 6.5, and 8.0 is presented. Stream Reynolds numbers ranged from 0.5 x 106 to 4.9 x 106 per foot and stream total temperature ranged from 2100 °R to 3400 °R. The model consisted of a 3-inch-diameter cylinder and a shock generation wedge articulated to angles of 10, 12.5, and 15 degrees. The primary goal of this study was to obtain a fundamental understanding of the fluid mechanics of shock wave …
A Numerical Study Of Three-Dimensional Vortex Breakdown, Robert Edward Spall
A Numerical Study Of Three-Dimensional Vortex Breakdown, Robert Edward Spall
Mechanical & Aerospace Engineering Theses & Dissertations
A numerical simulation of vortex breakdown using the time-dependent Navier-Stokes equations was performed. Unlike previous studies, the numerical algorithm, formulated in terms of the velocity and vorticity, was not restricted to axisymmetric flows. Prototype vortices were parameterized in terms of their Reynolds number and Rossby number. Two cases were studied extensively. In one case, a vortex was imbedded in a uniform free stream. In the other case, the axial velocity of the free stream was decelerated in the streamwise direction. For both cases breakdown occurred when the Rossby number was below a critical value. Vortex lines, particle traces and velocity …
Finite Element Methodology For Nonlinear Free And Harmonic Forced Vibrations Of Beam And Plate Structures, Kamolphan Decha-Umphai
Finite Element Methodology For Nonlinear Free And Harmonic Forced Vibrations Of Beam And Plate Structures, Kamolphan Decha-Umphai
Mechanical & Aerospace Engineering Theses & Dissertations
The literature and experiments have shown that nonlinear vibrations produce significant effects in structural analysis, especially the frequency-amplitude-force relation and the analysis of strain. An analysis was developed to predict both the frequency-amplitude-force relation and strains of beam and plate structures. Two finite element methods were developed, namely, the iterative single-mode method (method I) and the multiple-mode method (method II). The harmonic force matrix was developed to analyze nonlinear forced vibrations. Nonlinear free vibration was a special case of the general forced vibration by setting the harmonic force matrix equal to zero. The harmonic force matrix represents the external applied …