Title

Incorporation of Physics-Based Controllability Analysis in Aircraft Multi-Fidelity MADO Framework

Date of Award

1-1-2019

Degree Name

Ph.D. in Engineering

Department

Department of Electrical and Computer Engineering

Advisor/Chair

Advisor: Raúl Ordóñez

Abstract

A method is presented to incorporate physics-based controllability assessment in an aircraft Multi-disciplinary Analysis and Design Optimization environment with a target fidelity representing the traditional preliminary aircraft design phase. This method was designed with specific intended application to innovative vehicle concepts such as the Efficient Supersonic Air Vehicle, a tailless fighter-type aircraft which requires the use of innovative control effectors to achieve yaw control requirements. Typically, the layout of an aircraft is determined primarily through empirical design methods with minimal physical evaluation influencing the shape. As a result, the evaluation of new technologies such as these innovative control effectors in the past has been limited to placement and testing of them within existing free real estate on an otherwise complete vehicle design. The hypothesis of this dissertation is that inclusion of such technology in earliest stages of the design process has a greater chance of leading to optimal benefit and potentially a closed design for a tailless fighter-type aircraft. However, incorporation of technology that does not have a strong statistical basis through prior work requires some form of physical analysis to be performed in the design iteration. An aerodynamic study was performed to determine the optimal combination of fidelity and computation time for analyzing these types of configurations for the controls analysis in the MADO environment, resulting in the use of a multi-fidelity approach to aerodynamic analysis. This approach in turn requires a multi-fidelity, parameterized geometric model of the aircraft with automated generation of analysis mesh. In traditional aircraft design, the disciplines involved are isolated from each other in a linear manner such that one finishes prior to another beginning. Multidisciplinary approaches attempt to merge these. However, in open literature the fidelity level of various disciplines tends to have an inverse relationship. For example, the most complicated controllers explored in MADO tend to use the lowest fidelity aerodynamics and those that use higher fidelity aerodynamics tend to incorporate only a basic controllability assessment if any at all. In fact, this is the first known aircraft MADO effort to incorporate at least preliminary design levels of fidelity into both the aerodynamics and controls disciplines simultaneously. The approach of this dissertation was to test the implications of this by executing the MADO framework with both the low-fidelity aerodynamics and the multi-fidelity aerodynamics approach that is tailored to the controllability method desired. Using only the low-fidelity aerodynamics, the MADO result led to an infeasible aircraft configuration. However, the multi-fidelity approach resulted in an aircraft configuration markedly similar to previous real-life designs and with computed controllability in both the pitch and yaw axes optimized to be slightly above input design requirements.

Keywords

Aerospace Engineering, Engineering, aircraft design, multidisciplinary analysis and design optimization, mado, multidisciplinary design optimization, mdo, multidisciplinary analysis and optimization, mdao, conceptual design, control power required, control power available, multifidelity

Rights Statement

Copyright 2019, author

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