Aerodynamic and Acoustic Simulations of Thick Flatback Airfoils Employing High Order DES Methods

Abstract

The results of high fidelity aerodynamic and acoustic computations of thick flatback airfoils are reported in the present paper. The studies are conducted on a flatback airfoil having a relative thickness of 30% with the blunt trailing edge thickness of 10% relative to chord. Delayed Detached‐Eddy Simulation (DDES) approaches in combination with high order (5th) flux discretization WENO (Weighted Essentially Non‐Oscillatory) and l2Roe$l^{2}Roe$ Riemann solver are employed. Two variants of the DES length scale calculation methods are compared. The results are validated against experimental data with good accuracy. The studies provide guideline on the mesh and turbulence modeling selection for flatback airfoil simulations. The results indicate that the wake breakdown is strongly influenced by the spanwise resolution of the mesh, which directly contributes to the prediction accuracy especially for drag force and noise emission. The Reynolds normal stress u′u′¯$\overline{u^{\prime }u^{\prime }}$ and the u′v′¯$\overline{u^{\prime }v^{\prime }}$ Reynolds stress component have the largest contributions on the mixing process, while the contribution of the u′w′¯$\overline{u^{\prime }w^{\prime }}$ component is minimal. Proper orthogonal decomposition is further performed to gain deeper insights into the wake characteristics.

Utilizing high fidelity data into engineering model calculations for accurate wind turbine performance and load assessments under design load cases

“…The FLOWer code was adopted as the main workforce for performing CFD simulations in the present studies. The code was originally developed by the German Aerospace Center (DLR) [35], but has undergone significant improvement in helicopter and wind turbine simulation capabilities in the last decade at the University of Stuttgart [36][37][38][39]. FLOWer is a compressible code and solves the three-dimensional Navier-Stokes equations in an integral form with several turbulence models available.…”

Influence of the Blunt Trailing-Edge Thickness on the Aerodynamic Characteristics of the Very Thick Airfoil

“…For the numerical simulation method of flatback airfoils, it has been demonstrated that the load predictions obtained from 2D URANS simulations are acceptable [16,17]. The DES method has been proved to be a suitable method; the predicted forces and unsteady characteristics show excellent agreement with the experimental data [16][17][18][19]. The LES method is also a suitable method to study unsteady characteristics of flatback airfoils [20].…”

Investigating 3-D Flow Characteristics of Wind Turbine Airfoils using Delayed Detached Eddy Simulations at High Reynolds Numbers

“…De Oliveira et al [5] aimed to comprehend the effects of Reynolds and CFL numbers on flow patterns, addressing turbulence modeling challenges by utilizing OpenFOAM. Bangga et al [6] explored the DU97-W-300 airfoil using the DDES method within the FLOWer software. Their study discussed computational grid setup, time integration methods, and mesh refinement techniques.…”