Theses and Dissertations

ORCID

https://orcid.org/0000-0002-4461-0885

Issuing Body

Mississippi State University

Advisor

Bhushan, Shanti

Committee Member

Collins, Eric

Committee Member

Zope, Anup

Committee Member

Shinde, Vilas

Committee Member

Mohsen, Azimi

Date of Degree

12-13-2024

Original embargo terms

Worldwide

Document Type

Dissertation - Open Access

Major

Computational Engineering

Degree Name

Doctor of Philosophy (Ph.D.)

College

James Worth Bagley College of Engineering

Department

Computational Engineering Program

Abstract

The skin panels used in high-speed flights are exposed to various types of loads, such as inertial, elastic, and aerodynamic loads. In addition, oblique shock impingement can cause flow separation and unsteady aerodynamic loading, which can reduce vehicle performance and result in acoustic noise and viscous heating. These loads, when combined, can result in a complex dynamic response, such as flutter. Flutter is characterized by sustained unsteadiness or structural vibrations. Although flutter might not be immediately harmful, it can lead to fatigue failure of the structural components. A vast amount of literature already exists on the panel flutter induced by two and three-dimensional supersonic flows with oblique shock impingement. The majority of the studies are focused on predicting the onset of flutter and understanding the influence of non-dimensional parameters on the amplitude and frequency of the oscillations. Recently, numerous experimental campaigns were conducted to understand the influence of thermal loading on panel flutter and provide validation datasets to develop fluid-structure-thermal interaction solvers. The focus of this dissertation is divided into three tasks. The first task focuses on how shock impingement can affect the coupling between fluid and structural interactions and the onset of chaotic flutter. The second task focuses on controlling chaotic flutter using a passive micro vortex generator. The third task focuses on the development and validation of the fluid-structure-thermal interaction solver for 3D FSI problems. The results indicate that sufficiently strong shocks can induce flow separation and boundary layer instabilities that interact nonlinearly with the structural instabilities, resulting in chaotic oscillations. Micro vortex generators can delay the onset of the chaotic flutter by lowering the fluid frequency, thereby synchronizing fluid and structural unsteadiness. A thermoelastic solver has been developed, and the role of thermal stresses on panel flutter characteristics is considered a future task.

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