# Applied Math Colloquium: Dr Earl Dowell

## Duke University

2:30 PM - 3:30 PM

**Title: Theoretical Aeroelastic Models to Design and Correlate with Experimental Models **

Abstract: Aeroelasticity is the study of the dynamic interaction between an aerodynamic flow and a deforming elastic structure such as an aircraft, missile, rotorcraft or jet engine. A very important function of wind tunnel models and experiments is to verify a new aeroelastic theory or a new computational method. For this purpose, experimental aeroelastic model design and manufacturing of scaled models, benchtop experiments (in the absence of flow) and wind tunnel experiments are essential to success. In the past 20 years, the Duke group has designed many aeroelastic models and conducted wind tunnel experiments to evaluate new theoretical models and new computational methods. They include: (1) a high aspect ratio wing model; (2) wing like plate models, delta wing-store, flapping flag, yawed plate and folding wing models; (3) airfoil section with control surface freeplay; (4) all-movable tail with freeplay model at the root similar to the horizontal tail of an aircraft; (5) a free-to-roll fuselage flutter model; and (6) an experimental oscillating airfoil model at high angles of attack for measuring aerodynamic response. Several examples of models designed based upon theoretical (partial differential equation) models, wind tunnel experiments and experimental/theoretical correlation studies are presented. The goal is not only to evaluate a new theory or a new computational method, but also to provide new insights into nonlinear aeroelastic phenomena including flutter/Limit Cycle Oscillations (LCO) and gust response.

This is a joint colloquium with Mechanical Engineering department.