CAREER: Dynamics of Fluid-Structure-Control Interaction in Rotating Aerodynamic Bodies

Michigan Technological University, Houghton MI

Investigators

Abstract

ABSTRACT Studying the nonlinear dynamics of fluid structure interaction provides insights into a widespread physical topic which makes appearances in many scientific disciplines and several branches of Engineering. These phenomena manifest themselves at a wide range of scales and present excellent opportunities for scientific discovery with a richness of technical application. In cases like a rotor blade or an insect wing, where a body is subject to a complex motion due to the intrinsic operation of a certain mechanism or the dynamics of its control system, the scientific challenge is still greater. The objective of the research is to provide a better understanding of the underlying physics in slender body aeroelastic dynamics through improved mathematical computational models of the multiphysics process. The program is divided into three overlapping phases each of them building upon previous work the PI has published. The first phase focuses on a new series of adaptive algorithms, based on the hybrid (or vorticity-velocity) formulation of the Navier?Stokes equations. The kinematic Laplacian equation (KLE) technique will be used to create a complete decoupling of the two hybrid variables in a vorticity in time/velocity in space split approach. The resulting global scheme is intrinsically compatible with non-linear adaptive ODE algorithms, providing a way in which the submodels for the different problems involved (flow, structure, control system dynamics, etc.) may be treated individually as modules that interface with the main ODE routine. This allows for the simultaneous analysis of the aeroelastic problem together with any innovative control strategy into a single computationally efficient self adaptive algorithm. The second phase consists of qualitative studies on vortex-shedding and wake dynamics behind oscillating bodies, which play a critical role in the aeroelastic problem. In the third phase, quantitative studies on prototypes of innovative wind turbine blades, and their associated control strategies, will be conducted. Intellectual Merit: The intellectual merit of this work is the advancement of computational mathematical models for the com- plex multiphysics problems involving fluid structure control interaction that are present in many engineering designs, providing also a fundamental tool for a better understanding of the underlying physics. The experimental analysis of these coupled multiphysics problems is extremely difficult. In some cases (like wind turbine blades), huge size differences complicate extrapolation of experimental data from the wind tunnel to the prototype scale. In others (like the lifting surfaces used in Micro Air Vehicle applications inspired in the flapping-wing biological mechanisms observed in bird and insect flight), the sheer task of placing sensors on a small scale mechanism in complex rototranslational motion becomes almost insurmountable. If successful, the innovative mathematical models developed here will improve the efficiency and flexibility of the computational implementation and provide a way to tackle these difficulties. Broader Impacts: This work will promote teaching and learning at undergraduate and graduate levels, motivating engineering students to lead research at the frontiers of applied mathematics and computational mechanics. Besides their intrinsic scientific value as computational mathematics tools, the algorithms proposed here have a clear relevance to applications in many disciplines. In particular, the analysis of wind turbine blades constitutes a challenging problem in an emergent technological field of strategic relevance. Current blade technology based on composite laminates is labor intensive, requires a highly qualified workforce, and poses huge challenges in terms of transport logistics and crane capacity. It creates a critical bottleneck that hampers a rapid expansion of wind energy in the US. This work would have transformative effects in the development of wind turbine blade technology through synergistic activities in collaboration with high tech companies located in the region and with Sandia National Labs. Besides contributing to boost the local economy, these activities would help students to gain experience from an industrial research setting. This work intrinsically broadens the participation of underrepresented groups in research: both the PI and one PhD student involved are Hispanic, and the other PhD student is a woman. As part of the educational plan, a set of courses in renewable energies and sustainability will be taught in Spanish. Building upon previous PI's experience, and developed in collaboration with colleagues from the modern languages area, this aims to teach technical Spanish to English speaking engineering students at graduate and undergraduate level, providing a communicational bridge towards the Hispanic community. Expanded nationwide through Michigan Tech's Distance Learning Program, it would contribute to the rapid expansion of the sustainable energy workforce.