The simulation modeling of the flight dynamics of helicopters, and rotorcraft in general, is a multidisciplinary problem that involves dynamics, aerodynamics, structures, controls, and design optimization. The first part of the talk will describe the key portions of the mathematical model required for rotorcraft flight dynamics, which is typically composed of a system of nonlinear ordinary differential equations coupled with algebraic equations arising from computational fluid dynamics. The calculation of equilibrium (or trim) solutions, the linearized stability analysis, and the numerical integration of the equations of motion will also be described, together with the special techniques used to keep the calculations within real-time execution speeds.

The second part of the talk will describe some recent research in the development of mathematical models of coaxial rotor aerodynamics in state-space form. Current techniques used for single main rotor helicopter configurations are based on solutions of the acceleration potential equation over the rotor disk, but they cannot be extended to the coaxial rotor configurations currently envisioned for the next generation of military helicopters. The extraction of coaxial rotor aerodynamic models from free vortex wake theories using frequency domain system identification will be described, together with applications to coaxial helicopter flight dynamic modeling.



About the speaker...

Dr. Roberto Celi received his BS degree in Aeronautical Engineering from the Politecnico di Torino, Torino, Italy, and his MS and PhD in Aerospace Engineering from UCLA. He is currently a Professor in the Department of Aerospace Engineering at the University of Maryland, College Park, and is a member of the Alfred Gessow Rotorcraft Center, a US Army/US Navy/NASA Vertical Lift Research Center of Excellence. His primary areas of teaching and research are rotorcraft flight dynamics and control, and design optimization. Current research projects include: helicopter rotor aerodynamic modeling for flight dynamics application, multiobjective and multidisciplinary design optimization for redundant flight controls, modeling of ditching helicopters, and the analysis of helicopter pilot cognitive workload through brain and other physiological biomarkers.