Hypersonic Vehicle Design Course

USU MAE 6930

Spring 2024

Course Overview

This course was taught by Dr. Kevin Bowcutt, The Boeing Company's Chief Scientist of Hypersonics. The course was structured as a design competition between three different universities: Utah State University, Texas A&M University, and the University of Maryland. Each team was required to perform a market analysis, identify a profitable mission profile, and conceptualize an aircraft architecture.

Aircraft concepts were analyzed and matured throughout the semester under the guidance of Dr. Bowcutt. The analysis and integration of the following major disciplines was required for a successful design: aerodynamics, propulsion, aero-thermal, structures, configuration, trajectory optimization, stability and control, and mission/cost.

The USU team designed a Mach 5 passenger aircraft capable of carrying 20 passengers over 4500 nmi in under 2 hours. This aircraft was chosen as the winner of the competition at the end of the semester.

My roles on this project included:

Aerodynamic modeling, analysis, and design
Control and stability analysis and design
Support for the configuration, propulsion, and trajectory optimization sub-teams

Aerodynamic Modeling and Design

Aerodynamic analyses were required for takeoff and landing, transonic/supersonic acceleration, and hypersonic cruise flight conditions. Multiple tools/methods were required to generate the necessary aerodynamic database.

Our aerodynamic sub-group used the following tools to analyze and develop our aircraft:

Empirical methods for vortex lift/drag and wave drag estimates
VSPAERO - Subsonic and low supersonic Mach numbers (0.0 - 2.5)
CBAERO - Hypersonic Mach numbers (3.0 - 5.0) + viscous drag
FLUENT - Subsonic, supersonic, and hypersonic Mach numbers

Maximum lift over drag vs. Mach number

The maximum lift over drag of our aircraft compared well with the analytic Kuchemann limit and existing XB-70 flight test data. Our design met requirements for both takeoff and cruise performance.

Lift slope vs. Mach number after database corrections

We corrected our low-order aerodynamic data using high-fidelity CFD results. This greatly improved trends in important values such as the lift curve slope vs. Mach number while also keeping computational costs low.

Zero lift drag vs. Mach number

Our drag estimates compared well to XB-70 fight test data. With the inclusion of inlet drag estimates, we predicted reasonable transonic drag rise trends.

Viscous drag vs. Mach number

Viscous drag was the most difficult drag component for us to capture accurately. The low-fidelity methods were prone to underpredict viscous drag. The results were still reasonable at an engineering analysis level and useful for conceptual design applications.

Stability and Control Analysis

Because of the variation in aerodynamic center location with Mach number, the stability and controllability of our aircraft was a particularly difficult design challenge. For a conceptual design solution, we focused on shifting wing and stabilizer area aft of the center of gravity. We sized the elevator and rudders according to recommended volume coefficient guidelines. We iterated on designs until our aircraft was stable and trimmable at subsonic, supersonic, and hypersonic flight conditions.