說明 
235 p 
附註 
Source: Dissertation Abstracts International, Volume: 6602, Section: B, page: 1011 

Chair: Peretz P. Friedmann 

Thesis (Ph.D.)University of Michigan, 2005 

This dissertation describes the aeroelastic analysis of a generic hypersonic vehicle using methods in computational aeroelasticity. This objective is achieved by first considering the behavior of a representative configuration, namely a two degreeoffreedom typical crosssection, followed by that of a threedimensional model of the generic vehicle, operating at very high Mach numbers 

The typical crosssection of a hypersonic vehicle is represented by a doublewedge crosssection, having pitch and plunge degrees of freedom. The flutter boundaries of the typical crosssection are first generated using thirdorder piston theory, to serve as a basis for comparison with the refined calculations. Prior to the refined calculations, the timestep requirements for the reliable computation of the unsteady airloads using Euler and NavierStokes aerodynamics are identified. Computational aeroelastic response results are used to obtain frequency and damping characteristics, and compared with those from piston theory solutions for a variety of flight conditions. A parametric study of offsets, wedge angles; and static angle of attack is conducted. All the solutions are fairly close below the flutter boundary, and differences between the various models increase when the flutter boundary is approached. For this geometry, differences between viscous and inviscid aeroelastic behavior are not substantial 

The effects of aerodynamic heating on the aeroelastic behavior of the typical crosssection are incorporated in an approximate manner, by considering the response of a heated wing. Results indicate that aerodynamic heating reduces aeroelastic stability 

This analysis was extended to a generic hypersonic vehicle, restrained such that the rigidbody degrees of freedom are absent. The aeroelastic stability boundaries of the canted fin alone were calculated using thirdorder piston theory. The stability boundaries for the generic vehicle were calculated at different altitudes using piston theory for comparison. The flutter boundaries using firstorder piston theory were found to be much higher than those calculated using thirdorder piston theory. Computational aeroelastic response of the complete vehicle using Euler aerodynamics was found to predict a significantly higher flutter boundary as compared to thirdorder piston theory, due to substantial threedimensional flow effects. Also, both methods predicted an increase in the flutter boundary with increasing altitude 

School code: 0127 

DDC 
Host Item 
Dissertation Abstracts International 6602B

主題 
Engineering, Aerospace


0538

Alt Author 
University of Michigan

