Earl H Dowell

Professor Dowell's principal teaching interest and research activity is in the field of aeroelasticity - which is the study of the dynamic interaction between an aerodynamic flow and an elastic structure, such as aircraft wings in high speed flight, long span bridges and tall buildings responding to wind loadings, or airflow through the mouth and lungs. Dr. Dowell has also done research in acoustics, nonlinear dynamics, structural dynamics, and unsteady aerodynamics.

Professor Dowell's major research accomplishments include the first definitive research monograph on the aeroelasticity of plates and shells, the first derivation and solution of the nonlinear equations of motion for a helicopter rotor blade (the Hodges-Dowell equations), and work with Professor Kenneth Hall and several graduate students and post-doctoral fellows on reducing the dimensions of mathematical models for very complex high-dimensional fluid/structural systems. Professor Dowell teaches undergraduate and graduate courses on dynamics and aeroelasticity.

Here are six short videos showing experimental aeroelastic models undergoing limit cycle oscillations in the Duke wind tunnel.

1. An airfoil with a nonlinear freeplay in the connection from the main airfoil to the trailing edge control surface.
2. A delta wing with a strong structural nonlinearity as a result of tension in the mid-plane of the plate-like wing induced by bending of the wing out of its initially undeformed plane.
3. A very high aspect ratio wing that behaves as a beam with double bending (both transverse to and in-line with the aerodynamic flow field) and twisting. A nonlinear coupling among double bending and twisting occurs. Also the aerodynamic flow field experiences separation due to the large motions involved.
4. A delta wing with an external store, flutter and limit cycle oscillations.
5. LCO and Flutter of WingStore model
6. Flapping Flag Flutter

TEACHING (Fall 2009)

ME 210.01, INTERMEDIATE DYNAMICS, TuTh 10:05 AM-11:20 AM
ME 265.01, ADVANCED TOPICS, TuTh 10:05 AM-11:20 AM

TEACHING (Spring 2010)

ME 325.01, AEROELASTICITY,

Recent Publications More Publications

1. D. Tang and E. H. Dowell, Flutter/LCO suppression for high-aspect ratio wings, Aeronautical Journal, vol. 113 no. 1144 (2009), ppt. 409 -- 416 [abs]
   
2. J. W. Jaworski and E. H. Dowell, Comparison of Theoretical Structural Models with Experiment for a High-Aspect-Ratio Aeroelastic Wing, Journal Of Aircraft, vol. 46 no. 2 (2009), ppt. 708 -- 713
   
3. K. Ekici and K. C. Hall and E. H. Dowell, Computationally fast harmonic balance methods for unsteady aerodynamic predictions of helicopter rotors, Journal Of Computational Physics, vol. 227 no. 12 (2008), ppt. 6206 -- 6225 [abs]
   
4. J. W. Jaworski and E. H. Dowell, Free vibration of a cantilevered beam with multiple steps: Comparison of several theoretical methods with experiment, Journal Of Sound And Vibration, vol. 312 no. 4-5 (2008), ppt. 713 -- 725 [abs]
   
5. D. Tang and E. H. Dowell, Theoretical and experimental aeroelastic study for folding wing structures, Journal Of Aircraft, vol. 45 no. 4 (2008), ppt. 1136 -- 1147 [abs]