Abstract

In the first part of this thesis, the goal of the research is to implement and extend multi fidelity methods for conceptual design and optimization of a commercial supersonic transport (SST). Most modern commercial aircraft operate at a cruise condition between Mach 0.7 and 0.9, as this is the optimal trade-off of flight efficiency, operational cost, and adherence of noise regulations for overland travel. Advancements in aviation propulsion fuel efficiency and design materials suggests a primary restraint on commercial supersonic transport is noise regulations. At speeds above Mach 1, the shock waves generated by the airframe are strong enough to propagate from the aircraft to the ground. The amount of time between the pressure increases and decrease (compression and expansion) correlates with how loud the acoustic disturbance is. The Concorde flight profile and performance is used as a benchmark for the conceptual design presented here. Empirical methods have been implemented to size conceptual aircraft that can meet the minimum identified criteria for a modern supersonic transport. SUAVE, a multi-fidelity conceptual design tool, has been coupled with OpenVSP to analyze sonic boom overpressure of concepts at cruise condition. The sonic boom over pressure estimation implemented has been validated for the Concorde and the F5E Tiger II at supersonic conditions. SUAVE’s supersonic vortex lattice method is implemented to evaluate the concept cruise efficiency, takeoff and landing field lengths, and to identify op timal wing aspect ratio, wing sweep, and total wing area. Following preliminary sizing and evaluation, a baseline configuration is subjected to shape optimization aimed at minimizing sonic boom disturbance by employing a discrete adjoint approach in conjunction with invis cid flow solutions from the Euler equations. Relaxation of initial design constraints identifies a concept capable of 40 passengers, 4100 nmi range, cruise efficiency of 11, and reduction of sonic boom by 10 PLdB from the Concorde before shape optimization. In the second part of this thesis, the Wray-Agarwal (WA) and Wray-Agarwal Algebraic Tran sition (WAAT) model are validated for 2D benchmark validation cases. The one-equation WA turbulence model has shown to offer the numerical accuracy of multi equation turbu lence models at the computational expense of 1 transport equation. The second part of this thesis addresses validation and extension of the Wray-Agarwal Algebraic Transition (WAAT) model in Ansys Fluent and open-source solver SU2. The WAAT model is a local correlation model that delays turbulence production through an intermittency term that is calibrated based on local vorticity. The WAAT model has been validated for various ERCOFTAC and NASA Turbulence Modeling Resource (TMR) benchmark validation cases. In Ansys Fluent this model demonstrated similar and improved accuracy over higher order transition models for subsonic symmetric and asymmetric 2D airfoils, and for a simplified fuselage geometry (6:1 prolate spheroid). Implementation of a compressibility correction has shown the WAAT model is capable of accurate transition location prediction in both compressible and incompressible 2D flows. The Wray-Agarwal family of turbulence and transition mod els was recently implemented in SU2. Basic validation and verification work for the SU2 implementation is provided. A crossflow correction is implemented and calibrated for the WAAT model in SU2. The correction shows significant improvement in transition location prediction for the simplified fuselage.

Committee Chair

Ramesh Agarwal

Committee Members

Christian Rice; David Peters; Mark Meacham; Richard Axelbaum; Swami Karunamoorthy

Degree

Doctor of Philosophy (PhD)

Author's Department

Mechanical Engineering & Materials Science

Author's School

McKelvey School of Engineering

Document Type

Dissertation

Date of Award

8-18-2025

Language

English (en)

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