Session: 02-02-01: Aero-, Servo-, Thermo-Elastic Modeling and Optimization of Aerial Vehicles

Paper Number: 137516

137516 - Introduction to Aeroelasticity With a Doublet-Lattice-Method-Based Approach: A New Perspective 

Aeroelasticity indicates situations in which there is an interaction between elastic forces (due to the deformation of the structure), aerodynamic forces (due to the kinematics/geometry of the flying vehicle), and inertial forces (due to mass distribution and accelerations). The subject requires fundamental knowledge on various disciplines and that is why it is relatively difficult for new engineers and students. 

Aeroelasticity is usually introduced by presenting a Theodorsen-based two-dimensional aerodynamic model, which is typically very different than what engineers use in most of the practical industry applications which are focused on Doublet-Lattice Method (via NASTRAN) and ZAERO. 

It is introduced for the first time a new book on unsteady aerodynamics and dynamic aeroelasticity based on the Doublet Lattice Method. The following key aspects are covered:

1) Review of the mathematical concepts including singular integrals (Cauchy principal value and Hadamard finite part integrals)

2) Complete theoretical derivations of the acceleration potential equations

3) Derivations of the aeroelastic equations in the time and frequency domains

4) Demonstration of the expressions that lead to the formulation of the non-planar kernel 

5) Complete demonstration of the derivations needed to program the non-planar Doublet Lattice Method 

6) Formal justifications (including new derivations) of the doublet Lattice Method and its properties

7) Modal analysis, finite element method, and splining 

8) Theoretical derivations on Linear Time-Invariant Systems

8) Flutter rational function approximation, root locus and   various techniques used to calculate the flutter speed (k, k-E, p-k, non-iteratice p-k, g, second order g, GAMM, p, p-L, p-p, and Complex Velocity methods)

9) Body freedom flutter vs cantilever flutter, freeplay effects, Limit Cycle Oscillation, nonlinear dynamics and bifurcation diagrams

10) Nonlinear aeroelasticity of Joined Wings

Presenting Author: Luciano Demasi San Diego State University

Presenting Author Biography: Luciano Demasi is a professor at the Aerospace Engineering department (San Diego State University). His research interests are in the areas of structures, structural dynamics, and aeroelasticity