Engineering thought, in print.

Leading-edge vortex dynamics on finite-aspect-ratio swept wings exhibiting large-amplitude oscillations

Casey Fagley, Adam Jirasek, Jürgen Seidel

CEAS Aeronautical Journal 15(4) 999-1014 (2024) · doi:10.1007/s13272-024-00751-9

LEV growth, convection, and breakdown on a swept-wing platform under prescribed large-amplitude motion, directly applicable to agile, high-alpha, tailless airframes.

Wind Tunnel Evaluation of Control Effectiveness of an F-16 with a Bio-Inspired Rotating Empennage

Evan Komschlies, Casey Fagley

AIAA Regional Student Conferences (2024) · doi:10.2514/6.2024-86026

Wind-tunnel forces and moments on an F-16 with its vertical tail replaced by a rotating horizontal tail, at different rotation angles and Reynolds numbers; various angles give lateral and directional static stability comparable to the traditional F-16.

Vortex Interaction Characteristics of Multi-Swept Wings at Subsonic Speeds

Mehdi Ghoreyshi, Casey Fagley, Jürgen Seidel

AIAA Journal 61(7) 2932-2947 (2023) · doi:10.2514/1.j062605

Characterization of vortex-interaction physics across a family of multi-swept wing planforms: a strong correlation between the chord ratio of the initial sweep and the suppression of vortex breakdown.

Nonlinear, rate-dependent evaluation of flight damping derivatives of the Orion Crew Module

Casey P. Fagley, Robert M. Warner, Matthew R. Chmiel, Thomas R. Yechout

Journal of Spacecraft and Rockets 60(1) 239-248 (2023) · doi:10.2514/1.a35366

Time-accurate identification of rate-dependent damping for a re-entry capsule, informing dynamic-stability scheduling and certification methodology for a human-rated vehicle.

Efficiency analysis of the cycloidal wave-energy converter under real-time dynamic control using a 3D radiation model

Ali Mohtat, Casey Fagley, Kedar C. Chitale, Stefan G. Siegel

International Marine Energy Journal 5(1) 45-56 (2022) · doi:10.36688/imej.5.45-56

Closed-loop efficiency benchmarking of a cycloidal wave-energy device across sea states, combining hydrodynamic radiation theory with real-time controller-in-the-loop simulation.

Experiments on Vortical Interactions on Generic Multi-Swept Wing Configurations

Trevor D. Smiley, Carter C. Herman, Robert M. Warner, Casey P. Fagley, Mehdi Ghoreyshi, Jurgen Seidel

AIAA AVIATION 2022 Forum (2022) · doi:10.2514/6.2022-3303

Force/moment, surface oil flow and stereoscopic PIV measurements on a range of multi-swept planforms, determining how the sweep configuration drives vortex interactions and breakdown.

A Rate-Dependent and Time-Accurate Approach to Stability Evaluation of the NASA Orion Crew Module

Matthew R. Chmiel, Robert M. Warner, Casey P. Fagley, Thomas Yechout

AIAA SCITECH 2022 Forum (2022) · doi:10.2514/6.2022-0010

The companion conference paper to the J. Spacecraft & Rockets Orion work: rate-dependent, time-accurate methodology built around forced-motion identification.

Dynamic stability analysis of bluff-body re-entry vehicles using varying input excitation

Matthew Robbins, Alexander Yantis, Casey P. Fagley, Thomas R. Yechout

AIAA Scitech 2020 Forum (2020) · doi:10.2514/6.2020-1531

Forced-oscillation and free-oscillation campaigns at the U.S. Air Force Academy Subsonic Wind Tunnel characterize static pitch stability and pitch damping of the Orion Crew Module and Launch Abort Vehicle, compared with NASA historical data.

Feedback flow control: a heuristic approach

Jürgen Seidel, Casey Fagley, Thomas McLaughlin

AIAA Journal 56(10) 3825-3834 (2018) · doi:10.2514/1.j056884

A heuristic approach to feedback flow control, illustrated on a tangent ogive at large angles of attack and on the shear layer behind a backward-facing step; a wavenet ARX model with a sensor array co-located with the aperture reduced optical path difference by 40%.

Robust LQR control for stall flutter suppression: a polytopic approach

Fabien Niel, Alexandre Seuret, Luca Zaccarian, Casey Fagley

IFAC-PapersOnLine 50(1) 11367-11372 (2017) · doi:10.1016/j.ifacol.2017.08.2041

Polytopic robust-LQR synthesis for stall-flutter suppression on a NACA 0018 wing with a flap actuator, formulated with linear matrix inequalities; simulation results confirm the closed-loop behavior.

Developing a reduced order model from structural kinematic measurements of a flexible finite span wing in stall flutter

Ethan C.e. Culler, Casey Fagley, Jürgen Seidel, Thomas E. McLaughlin, John A.n. Farnsworth

Journal of Fluids and Structures 71 56-69 (2017) · doi:10.1016/j.jfluidstructs.2017.03.010

A measurement-driven reduced-order representation of stall-flutter kinematics: captures the dominant modes from structural data and provides a clean basis for closed-loop synthesis. J. Fluid Structures 71:56-69.

Cyber-physical flexible wing for aeroelastic investigation of stall and classical flutter

Casey Fagley, Jürgen Seidel, Thomas McLaughlin

Journal of Fluids and Structures 67 34-47 (2016) · doi:10.1016/j.jfluidstructs.2016.07.021

The cornerstone paper on the cyber-physical wind-tunnel methodology: emulating in-flight aerodynamic loads on a stationary model and collapsing flight-test feedback into the laboratory. J. Fluid Structures 67:34-47.

Closed-loop flow control of a forebody at a high incidence angle

Chris Porter, Casey Fagley, John Farnsworth, Jürgen Seidel, Thomas McLaughlin

AIAA Journal 52(7) 1430-1440 (2014) · doi:10.2514/1.j052563

Open-loop mass blowing near the tip of an axisymmetric forebody at high angle of attack gave a proportional side-force response; a linear model identified from it drove a proportional-integral law that tracks a set-point side force.

Open-Loop Dynamics of the Asymmetric Vortex Wake behind a von Kármán Ogive at High Incidence

Casey Fagley, John Farnsworth, Chris Porter, Jürgen Seidel, Thomas McLaughlin, Jinik Lee, Eunseok Lee

International Journal of Flow Control 5(1) 59-78 (2013) · doi:10.1260/1756-8250.5.1.59

Plasma actuators at the tip of a von Karman ogive (fineness ratio 3.5, Reynolds number 156,000) select a port or starboard asymmetric vortex state; open-loop tests give linear models, and a PID design tracks side force in closed-loop simulation.

Experimental wave termination in a 2D wave tunnel using a cycloidal wave-energy converter

S.g. Siegel, C. Fagley, S. Nowlin

Applied Ocean Research 38 92-99 (2012) · doi:10.1016/j.apor.2012.07.003

Experimental demonstration of wave cancellation by a phase-controlled cycloidal rotor, the empirical proof point underlying a decade of ocean-energy controller work. Applied Ocean Research 38:92-99.

Feedback control of a shear layer for aero-optic applications

Casey Fagley, Jürgen Seidel, Thomas McLaughlin

International Journal of Flow Control 3(1) 1-18 (2011) · doi:10.1260/1756-8250.3.1.1

A POD and wavenet reduced-order model of the shear layer behind a backward-facing step drives direct adaptive control; simulations indicate a 35% reduction in optical aberration.

Low-dimensional modelling of a transient cylinder wake using double proper orthogonal decomposition

Stefan G. Siegel, Jürgen Seidel, Casey Fagley, D. M. Luchtenburg, Kelly Cohen, Thomas McLaughlin

Journal of Fluid Mechanics 610 1-42 (2008) · doi:10.1017/s0022112008002115

The foundational coordinate-transformation paper anchoring the firm’s reduced-order-modeling practice: captures the transient non-linear cylinder wake in a minimum number of modes. J. Fluid Mechanics 610:1-42.

Wave Estimation Tool v1.1 - LSTM + Space-Time POD

A production PyTorch + Streamlit estimation tool for ocean wave-energy applications. Multi-horizon prediction of wave elevation from upstream sensor measurements; STPOD preprocessing; Airy / Stokes / JONSWAP / Bretschneider spectra; export to LabVIEW real-time targets.

Client tool, listed for completeness; no public DOI.