Bayesian inference of nonlinear unsteady aerodynamics from aeroelastic limit cycle oscillations

Journal Article · Fri Jul 01 00:00:00 EDT 2016 · Journal of Computational Physics

DOI:https://doi.org/10.1016/J.JCP.2016.03.006· OSTI ID:22572328

Sandhu, Rimple ^[1]; Poirel, Dominique ^[2]; Pettit, Chris ^[3]; Khalil, Mohammad ^[1]; Sarkar, Abhijit ^[1]

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1. Department of Civil and Environmental Engineering, Carleton University, Ottawa, Ontario (Canada)
2. Department of Mechanical and Aerospace Engineering, Royal Military College of Canada, Kingston, Ontario (Canada)
3. Department of Aerospace Engineering, United States Naval Academy, Annapolis, MD (United States)

A Bayesian model selection and parameter estimation algorithm is applied to investigate the influence of nonlinear and unsteady aerodynamic loads on the limit cycle oscillation (LCO) of a pitching airfoil in the transitional Reynolds number regime. At small angles of attack, laminar boundary layer trailing edge separation causes negative aerodynamic damping leading to the LCO. The fluid–structure interaction of the rigid, but elastically mounted, airfoil and nonlinear unsteady aerodynamics is represented by two coupled nonlinear stochastic ordinary differential equations containing uncertain parameters and model approximation errors. Several plausible aerodynamic models with increasing complexity are proposed to describe the aeroelastic system leading to LCO. The likelihood in the posterior parameter probability density function (pdf) is available semi-analytically using the extended Kalman filter for the state estimation of the coupled nonlinear structural and unsteady aerodynamic model. The posterior parameter pdf is sampled using a parallel and adaptive Markov Chain Monte Carlo (MCMC) algorithm. The posterior probability of each model is estimated using the Chib–Jeliazkov method that directly uses the posterior MCMC samples for evidence (marginal likelihood) computation. The Bayesian algorithm is validated through a numerical study and then applied to model the nonlinear unsteady aerodynamic loads using wind-tunnel test data at various Reynolds numbers.

• OSTI ID: 22572328
• Journal Information: Journal of Computational Physics, Vol. 316; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AERODYNAMICS
ALGORITHMS
APPROXIMATIONS
BOUNDARY LAYERS
COMPUTERIZED SIMULATION
DIFFERENTIAL EQUATIONS
FLUID-STRUCTURE INTERACTIONS
LIMIT CYCLE
MARKOV PROCESS
MONTE CARLO METHOD
NONLINEAR PROBLEMS
NUMERICAL ANALYSIS
OSCILLATIONS
PROBABILITY DENSITY FUNCTIONS
REYNOLDS NUMBER
WIND TUNNELS