Ph.D. Defense
Hayden Valerie Dean
(Advisor: Prof. Mavris)
A Reduced Order Modeling Methodology for Quantifying Entry Capsule Aerodynamics in Modeling and Simulation
On
Monday, March 17
12:00 p.m.
Collaborative Visualization Environment (CoVE) Weber Space and Technology Building (SST II)
And
Abstract
Entry, descent, and landing (EDL) is a critical aspect of planetary missions enabling payloads to safely land on planetary surfaces. To ensure mission success, engineers rely on advanced Modeling and Simulation (M&S), leveraging Monte Carlo analysis to identify mission sensitivities resulting from uncertainties. Of all the uncertainties modeled, aerodynamic uncertainty is the most impactful, affecting vehicle design, subsystem needs, and feasible trajectories. Vehicle aerodynamic behaviors are incorporated into M&S through aerodynamic databases. Computational Fluid Dynamics (CFD)-in-the-loop flight simulations are considered to be the state-of-the-art for incorporating aerodynamic data into EDL M&S, but the data requirements make them too computationally expensive to apply at scale. Therefore, there is an industry need to incorporate high-fidelity aerodynamic data into EDL M&S without developing costly aerodynamic databases.
Literature identifies surrogate modeling as a way to efficiently incorporate high-fidelity data into coupled analysis frameworks like EDL M&S. Reduced Order Models (ROMs) are an emerging surrogate modeling technique that can leverage high-fidelity aerodynamic data to predict a field of responses, containing more information in a single model than what is possible with data fit surrogate models. Fundamentally, ROMs aim to find a low-dimensional representation of a high-fidelity Full-Order Model (FOM).
Key gaps were identified through literature, addressing the needs for developing a ROM capable of predicting high-dimensional, unsteady, parametric, low supersonic to transonic entry capsule data for EDL M&S. Research Questions and Experimentation seek to find a Dimensionality Reduction (DR) technique and advanced regression strategy for the ROM to achieve the necessary fidelity of predicting entry capsule aerodynamics on a test set of CFD pressure and shear surface data, and develop a sampling strategy for Free-Flight-CFD (FF-CFD) to develop a free-flight ROM.
The overarching research hypothesis aimed to develop a ROM methodology to model low supersonic to transonic entry capsule aerodynamics in EDL M&S. The ROM bypasses the need to calculate complex dynamic stability coefficients by predicting the surface aerodynamic fields of the vehicle in free-flight. The developed ROM methodology was implemented into EDL M&S, creating a ROM-in-the-loop flight simulation capability to assess the predictive performance of the ROM in dynamic simulations.
Committee
- Prof. Dimitri Mavris – School of Aerospace Engineering (advisor)
- Prof. Lakshmi Sankar – School of Aerospace Engineering
- Prof. Graeme Kennedy – School of Aerospace Engineering
- Dr. Bradford Robertson – School of Aerospace Engineering
- Dr. D. Bruce Owens – Flight Dynamics Branch, NASA Langley Research Center