Control of Tailless
Morphing Aircraft

Office of Naval Research - Young Investigator Program Award

June 2018 - May 2022

$510,000

Project Overview

The next generation of fighter aircraft will be tailless. One significant challenge that must be addressed in order to make this a reality is yaw control. The present work considers the use of morphing technology to produce sufficient roll, pitch, and yaw control for tailless aircraft. The overall hypothesis is that the fundamental relationships between aerodynamics and wind morphology can be exploited to produce adequate longitudinal and lateral control for tailless aircraft.

Objectives

Statistics

18 Morphing-Wing Concepts

Final Presentation Recordings

1- Introduction

2- Lift Distributions

3- Analytic Roll/Yaw Control

4- Aileron Placement

5- Swept and Crescent Wings

6- Lifting-Line Algorithm for Wings with Sweep

7- MachUp X

8- Morphing Wing Design

9- Manufacturing and Assembly

10- Aircraft Checkout

11- Control Mapping

12- Flight Testing

13 - Recap

Full Presentation Playlist

Publications

Journal Publications

Modern Implementation and Evaluation of Lifting-Line Theory for Complex Geometries

Goates, C., and Hunsaker, D. F., “Modern Implementation and Evaluation of Lifting-Line Theory for Complex Geometries,” Journal of Aircraft, In Review

Accuracy of KĂĽchemann's Prediction for the Locus of Aerodynamic Centers on Swept Wings

Moorthamers, B., and Hunsaker, D. F., “Accuracy of Küchemann's Prediction for the Locus of Aerodynamic Centers on Swept Wings,” The Aeronautical Journal, April 2022, 21 pages, DOI: 10.1017/aer.2022.34.

Minimum-Series Twist Distributions for Yawing-Moment Control During Pure Roll

Hunsaker, D. F., Moorthamers, B., and Joo, J., “Minimum-Series Twist Distributions for Yawing-Moment Control During Pure Roll,” Zeitschrift für Angewandte Mathematik und Mechanik, May 2021, 19 pages, DOI: 10.1002/zamm.201900177

Aileron Size and Location to Minimize Induced Drag During Roll Initiation

Brincklow, J., and Hunsaker, D. F., “Aileron Size and Location to Minimize Induced Drag During Roll Initiation,” The Aeronautical Journal, Vol. 125, No. 1287, 2021, pp. 807–829, DOI: 10.1017/aer.2020.139

General Approach to Lifting-Line Theory, Applied to Wings with Sweep

Reid, J. T., and Hunsaker, D. F., “A General Approach to Lifting-Line Theory, Applied to Wings with Sweep,” Journal of Aircraft, Vol. 58, No. 2, 2021, pp. 334-346 DOI: 10.2514/1.C035994

Adverse-Yaw Control During Roll for a Class of Optimal Lift Distributions

Hunsaker, D. F., Montgomery, Z. S., and Joo, J. J., "Adverse-Yaw Control During Roll for a Class of Optimal Lift Distributions," AIAA Journal, Vol. 58, No. 7, pp. 2909-2920, 2020, DOI: 10.2514/1.J059038

Minimising induced drag with weight distribution, lift distribution, wingspan, and wing-structure weight

Phillips, W. F., Hunsaker, D. F., and Taylor, J. D., "Minimising induced drag with weight distribution, lift distribution, wingspan, and wing-structure weight," The Aeronautical Journal, Vol. 124, No. 1278, pp. 1208-1235, 2020, DOI: 10.1017/aer.2020.24

Designing Wing Twist or Planform Distributions for Specified Lift Distributions

Phillips, W. F. and Hunsaker, D. F., "Designing Wing Twist or Planform Distributions for Specified Lift Distributions," Journal of Aircraft, Vol. 56, No. 2, pp. 847-849, 2019, DOI: 10.2514/1.C035206

Conference Publications

Control Mapping Methodology for Roll, Pitch, and Yaw Control on Morphing-Wing Aircraft

Montgomery, Z., and Hunsaker, D. F., “Control Mapping Methodology for Roll, Pitch, and Yaw Control on Morphing-Wing Aircraft,” AIAA SciTech Forum, January 2022, AIAA-2022-2531, DOI: 10.2514/6.2022-2531

Design and Performance of a 3D-Printed Morphing Aircraft

Snow, S. A., and Hunsaker, D. F., “Design and Performance of a 3D-Printed Morphing Aircraft,” AIAA Scitech Forum Virtual Event, January 2021, AIAA-2021- 1060 DOI: 10.2514/6.2021-1060

Link to Video Presentation

3D-Printed Wings with Morphing Trailing-Edge Technology

Moulton, B. C., and Hunsaker, D. F., “3D-Printed Wings with Morphing Trailing-Edge Technology,” AIAA Scitech Forum Virtual Event, January 2021, AIAA-2021-0351 DOI: 10.2514/6.2021-0351

Link to Video Presentation

Controlling Roll-Yaw Coupling with Aileron Placement and Wing Twist

Brincklow, J. R., Montgomery, Z. S., and Hunsaker, D. F., "Controlling Roll-Yaw Coupling with Aileron Placement and Wing Twist," AIAA SciTech Forum Virtual Event, January 2021, DOI: https://doi.org/10.2514/6.2021-0327 

Link to Video Presentation 

Sensitivity and Estimation of Flying-Wing Aerodynamic, Propulsion, and Inertial Parameters Using Simulation

Thurgood, J. W., and Hunsaker, D. F., "Sensitivity and Estimation of Flying-Wing Aerodynamic, Propulsion, and Inertial Parameters Using Simulation," AIAA SciTech Forum Virtual Event, January 2021, AIAA-2021-1528, DOI: 10.2514/6.2021-1528 

Link to Video Presentation 

Estimation of Incompressible Swept-Wing Aerodynamics Using Low-Fidelity Methods

Moorthamers, B., Wiberg, D., and Hunsaker, D. F., "Estimation of Incompressible Swept-Wing Aerodynamics Using Low-Fidelity Methods," AIAA SciTech Forum Virtual Event, January 2021, AIAA-2021-1825, DOI: 10.2514/6.2021-1825

Practical Implementation of a General Numerical Lifting-Line Method

Goates, C., and Hunsaker, D. F., "Practical Implementation of a General Numerical Lifting-Line Method," AIAA SciTech Forum Virtual Event, January 2021, AIAA-2021-0118, DOI: 10.2514/6.2021-0118

Optimization of Ailerons to Minimize Induced Drag in Roll

Brincklow,  J.  R.,  and Hunsaker,  D.  F., “Optimization of Ailerons to Minimize Induced Drag in Roll,” AIAA Scitech Forum, Orlando, Florida, January 2020, AIAA-2020-0279, DOI: 10.2514/6.2020-0279

Accuracy of KĂĽchemann's Prediction for the Locus of Aerodynamic Centers on Swept Wings

Moorthamers, B.,  and Hunsaker,  D.  F., “Accuracy of Küchemann's Prediction for the Locus of Aerodynamic Centers on Swept Wings,” AIAA  Scitech  Forum,  Orlando,  Florida,  January  2020, AIAA-2020-0533 , DOI: 10.2514/6.2020-0533

Ludwig Prandtl’s 1933 Paper Concerning Wings for Minimum Induced  Drag,  Translation  and  Commentary

Hunsaker,  D.  F., and Phillips, W. F., “Ludwig Prandtl’s 1933 Paper Concerning Wings for Minimum Induced  Drag,  Translation  and  Commentary,” AIAA  Scitech  Forum,  Orlando,  Florida,  January  2020, AIAA-2020-0644 , DOI: 10.2514/6.2020-0644

Control of Adverse Yaw During Roll for a Class of Optimal Lift Distributions

Hunsaker,  D.  F., Montgomery, Z. S., and Joo, J. J., “Control of Adverse Yaw During Roll for a Class of Optimal Lift Distributions,” AIAA Scitech Forum, Orlando, Florida, January 2020, AIAA-2020-1264, DOI: 10.2514/6.2020-1264

A General Approach to Lifting-Line  Theory,  Applied  to  Wings  with Sweep

Reid,  J.  T.  and Hunsaker,  D.  F., “A General Approach to Lifting-Line  Theory,  Applied  to  Wings  with Sweep,” AIAA Scitech Forum, Orlando, Florida, January 2020, AIAA-2020-1287,  DOI: 10.2514/6.2020-1287

Minimizing Induced Drag with Weight Distribution, Lift Distribution, Wingspan, and Wing-Structure Weight

Phillips, W. F., Hunsaker, D. F., and Taylor, J., “Minimizing Induced Drag with Weight Distribution, Lift Distribution,  Wingspan,  and  Wing-Structure  Weight,” AIAA Aviation Forum, Dallas, Texas, June 2019, AIAA-2019-3349, DOI: 10.2514/6.2019-3349

Effects of Sweep on Airfoil Section Properties

Reid, J. T., and Hunsaker,  D.  F., “Effects of Sweep on Airfoil Section Properties,” AIAA Aerospace Sciences  Meeting,  San  Diego,  California, January 2019, AIAA-2019-2118, DOI: 10.2514/6.2019-2118

Aerodynamic Center at the Root of Swept, Elliptic Wings in Inviscid Flow

Moorthamers, B., and Hunsaker,  D.  F., “Aerodynamic Center at the Root of Swept, Elliptic Wings in Inviscid Flow,” AIAA Aerospace Sciences  Meeting,  San  Diego,  California, January 2019, AIAA-2019-0032, DOI: 10.2514/6.2019-0032

Theses / Dissertations

Software Packages

Open Aircraft Designs

4-ft 3D Printed Flying-Wing Aircraft with traditional ailerons

10-ft 3D printed Flying-Wing Aircraft with 11 conformal flaps

Aircraft Design, Print, and Assembly

Conformal Flap Design and Prototyping

Many videos available here.

Final Conformal Flap Design

Horizon Airframe 3D Printing Time Lapse

Horizon Airframe Assembly Time Lapse

Glide Test

April 15, 2021

Purpose: To test the following:

Outcome: Successful glide test. CG location seems to produce adequate static stability.

1st Powered Test

May 3, 2021

Aircraft: V3

Purpose: Test the following:

Outcomes: Aircraft exhibited aeroelastic behavior with repeated instances of intermittent flutter (see t=1.25 min). Test ended with catastrophic flutter event at t=2:10 min. Controllability difficult to discern due to flutter. Ducted fans produced less thrust than expected. Trim required a throttle setting of about 75%.

Flight Time: 00:01:49

2nd Powered Test

June 29, 2021

Aircraft: V4

Purpose: Test the following:

Outcome: Aircraft sufficiently rigid. No flutter issues. Trim required less throttle (about 66%) most likely due to new ESC. Flight test routine and documentation greatly improved. Dutch roll not as damped as desirable for good handling qualities (see t=4:57 in video). Intermittent loss of signal between receiver and transmitter caused intermittent pitch pulses throughout flight (see t=2:07). Loss of signal eventually lead to catastrophic loss of control (see t=5:16). Loss of signal most likely due to a loose connection on the receiver.

Flight Time: 00:04:18

3rd Powered Test

October 7, 2021

Aircraft: V6 M2

Purpose: Test the following:

Outcome: Crash on takeoff. Video and other data used for crash analysis.

Flight Time: 00:00:06

4th Powered Test

November 4, 2021

Aircraft: V7 M2

Purpose: Test the following:

Outcome: Clean launch. Stable with plenty of power. Center section conformal flap checks out. Sufficient data collected to test ranges of pbar and Cm commanded by pilot. Aircraft felt sluggish in the air. Motors sputtered and servos froze in air repeatedly. Could be due to loss of signal. This behavior caused final crash.

Flight Time: 00:03:00

5th Powered Test

April 27, 2022

Aircraft: V8 M2

Goals:

Outcome: Clean launch. Stable with plenty of power in Mode 1. Zero drops in communication. When switching to Mode 2, the aircraft was trimmed (from Mode 1) with pitch up. The aircraft pitched up as it entered Mode 2 and entered a glide slope that could not be shaken. Hard landing, but with wings level.

Flight Time: 00:01:32

6th Powered Test

May 23, 2022

Aircraft: V9 M2

Goals:

Outcome: Issue during launch. Launch mechanism wrapped around wing. Wing snapped due to possible faulty construction.

Flight Time: 00:00:02

7th Powered Test

June 6, 2022

Aircraft: V10 M2

Goals:

Outcome: Nearly perfect flight. Clean launch. Grazed the ground a little close to the bungee stakes during launch. Solid flight. Spent 2 minutes 12 seconds in Mode 2. Firm touch down broke up the aircraft.

Flight Time: 00:04:36

8th Powered Test

June 9, 2022

Aircraft: V11 M2

Goals:

Outcome: Beautiful launch. Clean transition from Mode 1 to Mode 4. Successful turn in Mode 4. Tested right and left yaw command. Flutter event caused aircraft to break up in the air.

Flight Time: 00:02:29

Annotated Yaw Control and Flutter Event

Control Mapping

Control surface deflections as viewed from the back of the aircraft.

These deflections depend on commands from the pilot as well as the current state of the aircraft.

Mode 1 (Safety)

Control surfaces act in unison as elevons.

Mode 2

Minimum drag with prescribed rolling rate and pitching moment.

Mode 3

Minimum drag and zero yawing moment with prescribed rolling rate and pitching moment.

Mode 4

Minimum drag with prescribed rolling rate, pitching moment, and yawing moment.

Mode Demonstration on the Horizon Aircraft.

Students

PhD

Jackson Reid

Bruno Moorthamers

Zachary Montgomery

Cory Goates

MS

Josh Brincklow

Jaden Thurgood

Sabrina Snow

Ben Moulton

Undergraduate

Dallin Wiberg

Josh Hurwitz

Weston Bowcutt