Stabilization of Linear Flow Solver for Turbomachinery Aeroelasticity Using Recursive Projection Method
نویسندگان
چکیده
The linear analysis of turbomachinery aeroelasticity relies on the assumption of small level of unsteadiness and requires the solution of both the nonlinear steady and the linear unsteady flow equations. The objective of the analysis is to compute a complex flow solution that represents the amplitude and phase of the unsteady flow perturbation for the frequency of unsteadiness of interest. The solution procedure of the linear harmonic Euler/Navier–Stokes solver of the HYDRA suite of codes consists of a preconditioned fixed-point iteration, which in some circumstances becomes numerically unstable. Previous work had already highlighted the physical origin of these numerical instabilities and demonstrated the code stabilization achieved by wrapping the core part of the linear code with a Generalized Minimal Residual (GMRES) solver. The implementation and the use of an alternative algorithm, namely, the Recursive Projection Method, is summarized. This solver is shown to be well suited for both stabilizing the fixed-point iteration and improving its convergence rate in the absence of numerical instabilities. In the framework of the linear analysis of turbomachinery aeroelasticity, this method can be computationally competitive with the GMRES approach.
منابع مشابه
Computing Linear Harmonic Unsteady Flows in Turbomachines with Complex Iterative Solvers
The linear flow analysis of turbomachinery aeroelasticity views the unsteady flow as the sum of a background nonlinear flow field and a linear harmonic perturbation. The background state is usually determined by solving the nonlinear steady flow equations. The flow solution representing the amplitude and phase of the unsteady perturbation is instead given by the solution of a large complex line...
متن کاملTorsional Aeroelasticity of a Flexible VAWT Blade using a Combined Aerodynamic Method by Considering Post-stall and Local Reynolds Regime
The present research investigates the torsional aeroelasticity of the blade of an H-type vertical axis wind turbine subject to stall and post-stall conditions in various Reynolds regimes, which is experienced by the blade in a full revolution. In order to simulate the aerodynamics, a new model based on a combination of the Double Multi Streamtubes (DMST) model and the nonlinear multi-criteria C...
متن کاملOrr Sommerfeld Solver Using Mapped Finite Di?erence Scheme for Plane Wake Flow
Linear stability analysis of the three dimensional plane wake flow is performed using a mapped finite di?erence scheme in a domain which is doubly infinite in the cross–stream direction of wake flow. The physical domain in cross–stream direction is mapped to the computational domain using a cotangent mapping of the form y = ?cot(??). The Squire transformation [2], proposed by Squire, is also us...
متن کاملFluid/structure Coupled Aeroelastic Computations for Transonic Flows in Turbomachinery
The present study demonstrates the capabilities of a fluid/structure coupled computational approach which consists of an unsteady three-dimensional Navier-Stokes flow solver, TFLO, and a finite element structural analysis package, MSC/NASTRAN. The parallelized flow solver relies on a multiblock cell-centered finite volume discretization and the dual time stepping time integration scheme with mu...
متن کامل