Open Access. Powered by Scholars. Published by Universities.^{®}
Engineering Science and Materials Commons^{™}
Open Access. Powered by Scholars. Published by Universities.^{®}
 Discipline
 Keyword

 Stage separation (1)
 Flow control (1)
 Cones (1)
 Linear topological spaces (1)
 Modal parameters (1)

 Acoustic disturbances (1)
 Vibration (1)
 Hypersonic (1)
 Interface technology (1)
 Relativemoving boundary (1)
 Multifunctional collaborative methods (1)
 Delta wings (1)
 Hypersonic boundary layer (1)
 Aerodynamic response (1)
 Finite element method (1)
 Pitching (1)
 Piezoelectric actuators (1)
 Dynamic unstructured (1)
 Unsteady flows (1)
 Active control (1)
 Automatic control (1)
Articles 1  6 of 6
FullText Articles in Engineering Science and Materials
Hypersonic Boundary Layer Receptivity To Acoustic Disturbances Over Cones, Kursat Kara
Hypersonic Boundary Layer Receptivity To Acoustic Disturbances Over Cones, Kursat Kara
Mechanical & Aerospace Engineering Theses & Dissertations
The receptivity mechanisms of hypersonic boundary layers to free stream acoustic disturbances are studied using both linear stability theory (LST) and direct numerical simulations (DNS). A computational code is developed for numerical simulation of steady and unsteady hypersonic flow over cones by combining a fifthorder weighted essentially nonoscillatory (WENO) scheme with thirdorder totalvariationdiminishing (TVD) RungeKutta method. Hypersonic boundary layer receptivity to freestream acoustic disturbances in slow and fast modes over 5degree, halfangle blunt cones and wedges are numerically investigated. The freestream Mach number is 6.0, and the unit Reynolds number is 7.8×106/ft. Both the steady and ...
On Multifunctional Collaborative Methods In Engineering Science, Jonathan B. Ransom Sr.
On Multifunctional Collaborative Methods In Engineering Science, Jonathan B. Ransom Sr.
Mechanical & Aerospace Engineering Theses & Dissertations
Engineers are challenged to produce better designs in less time and for less cost. Hence, to investigate novel and revolutionary design concepts, accurate, highfidelity data must be assimilated rapidly into the design, analysis and simulation process. This data assimilation should consider diverse mathematical modeling and multidiscipline interactions necessitated by concepts exploiting advanced materials and structures. Integrated highfidelity methods with diverse engineering applications provide the enabling technologies to assimilate these highfidelity, multidisciplinary data rapidly at an early stage in the design. These integrated methods must be multifunctional, collaborative and applicable to the general field of engineering science and mechanics.
Multifunctional methodologies ...
Large Amplitude Pitching Of Supermaneuver Delta Wings Including Flow Control, Yahia A. Abdelhamid
Large Amplitude Pitching Of Supermaneuver Delta Wings Including Flow Control, Yahia A. Abdelhamid
Mechanical & Aerospace Engineering Theses & Dissertations
The unsteady, threedimensional NavierStokes equations are solved to simulate and study the aerodynamic response of a delta wing undergoing large amplitude pitching motion up to 90° angle of attack. The primary model under consideration consists of a 76° swept, sharpedged delta wing of zero thickness, initially at zero angle of attack. The freestream Mach number and Reynolds number are 0.3 and 0.45 × 106, respectively. The governing equations are solved timeaccurately using the implicit, upwind, Roe fluxdifference splitting, finitevolume scheme. Both laminar and turbulent flow solutions are investigated. In the laminar flow solutions, validation of the computational results is ...
Efficient Dynamic Unstructured Methods And Applications For Transonic Flows And Hypersonic Stage Separation, Xiaobing Luo
Efficient Dynamic Unstructured Methods And Applications For Transonic Flows And Hypersonic Stage Separation, Xiaobing Luo
Mechanical & Aerospace Engineering Theses & Dissertations
Relativemoving boundary problems have a wide variety of applications. They appear in staging during a launch process, store separation from a military aircraft, rotorstator interaction in turbomachinery, and dynamic aeroelasticity.
The dynamic unstructured technology (DUT) is potentially a strong approach to simulate unsteady flows around relativemoving bodies, by solving timedependent governing equations. The dualtime stepping scheme is implemented to improve its efficiency while not compromising the accuracy of solutions. The validation of the implicit scheme is performed on a pitching NACA0012 airfoil and a rectangular wing with low reduced frequencies in transonic flows. All the matured accelerating techniques, including the ...
Placement Of Piezoelectric Actuators For Active Control Of Vibration Using Modal Parameters, Xuegeng Zhu
Placement Of Piezoelectric Actuators For Active Control Of Vibration Using Modal Parameters, Xuegeng Zhu
Mechanical & Aerospace Engineering Theses & Dissertations
An equation is derived to model the piezoelectric actuators incorporation with flexible structures. This equation permits the comparison of the performance indices over the entire structure for a piezoelectric actuator with constant area, which is unachievable if the Finite Element Method is used for complicated structures.
An index has been developed for placement of piezoelectric actuator for control of vibration of a flexible structure. This index is derived from the definition of H2norm. Computation of the proposed index requires only the natural frequencies and corresponding mode shapes of the structures of interest. The method is well suited to large ...
Development Of Vibration And Sensitivity Analysis Capability Using The Theory Of Structural Variations, TingYu Rong
Development Of Vibration And Sensitivity Analysis Capability Using The Theory Of Structural Variations, TingYu Rong
Mechanical & Aerospace Engineering Theses & Dissertations
In the author's previous work entitled "General Theorems of Topological Variations of Elastic Structures and the Method of Topological Variation," 1985, some interesting properties of skeletal structures have been discovered. These properties have been described as five theorems and synthesized as a theory, called the theory of structural variations (TSV). Based upon this theory, an innovative analysis tool, called the structural variation method (SVM), has been derived for static analysis of skeletal structures (onedimensional finite element systems).
The objective of this dissertation research is to extend TSV and SVM from onedimensional finite element systems to multidimensional ones and from ...