Chelsea Johnson

(Advisor: Professor Joseph C. Oefelein)

will propose a doctoral thesis entitled,

A Coupled Wall-Model Framework for Large Eddy Simulation of Shock-Wave/Boundary-Layer and Fluid-Structure Interactions

On

Monday, April 4th at 1:00 p.m.

In

Skiles Classroom 5 (Virtual)

 

Abstract

A computational framework for the prediction and analysis of high Reynolds number SBLI over elastic panels is herein developed and presented. The framework features WMLES loosely coupled to an aeroelastic solver enabling accurate and affordable two-way coupled fluid-structure simulations. Additionally, the performance of equilibrium and non-equilibrium wall models is compared in an a priori analysis using a scaled low Reynolds number wall-resolved LES dataset. Two approaches for accounting for non-equilibrium effects of SBLI flows are implemented, extending previous work on the subject. Separation length is used as the primary metric of performance and computational time is compared between models and non-equilibrium model variants. A new approach to fluid-structure interactions is developed and deployed in a WMLES. This method uses a time-dependent boundary condition to represent the effect of the moving panel on the flow. The approach is intended to be simpler to implement in LES codes than existing FSI methods, as well as computationally inexpensive. The two-way-coupled simulation is compared to an experimental counterpart that examines the structural response of an elastic panel to an impinging SBLI on a high Reynolds number turbulent boundary layer. The two-way coupled simulation is evaluated quantitatively using low frequency shock motion, wall-pressure spectra, separation bubble size, and the dynamics of the elastic panel. The framework yields results which show good agreement with the corresponding wind tunnel experiment in several metrics including separation bubble length, shock frequency, static panel deformation, and modifications to wall-pressure spectra due to panel motion. Differences in the one-way and two-way coupled simulations are examined and pressure coherence fields are shown to be strongly affected by the inclusion of structural motions. Finally, recommendations are issued for the use of the framework in future interaction simulations.

Committee

• Prof. Joseph C. Oefelein – School of Aerospace Engineering (advisor), Georgia Institute of Technology

• Prof. Cristina Riso – School of Aerospace Engineering, Georgia Institute of Technology

• Prof. Lakshmi N. Sankar – School of Aerospace Engineering, Georgia Institute of Technology

• Prof. Earl H. Dowell – Department of Mechanical Engineering and Materials Science, Duke University

• Prof. Venkat Narayanaswamy – Department of Mechanical and Aerospace Engineering, North Carolina State University