A Surrogate Based Approach to Reduced-Order Dynamic Stall Modeling

Abstract

The surrogate-based recurrence framework (SBRF) approach to reduced-order nonlinear unsteady aerodynamic modeling associated with pitching/plunging airfoils subject to xed or time-varying freestream Mach numbers is described. Using full-order solutions generated by the OVERFLOW CFD code, the SBRF reduced-order modeling approach is shown to eectively mimic full-order solutions of unsteady lift, moment, and drag under dynamic stall conditions, but at a fraction of the computational cost. In addition to accounting for realistic helicopter rotor blade dynamics, it is shown that the SBRF can model advancing rotor blade stall due to shock induced separation, as well as retreating blade stall associated with excessive angles of attack. Therefore, the SBRF reduced-order modeling approach is ideally suited for a variety of aeroelasticity and active/passive design optimization studies that require high delity aerodynamic response solutions with minimal computational expense.