Large-eddy simulation of flows past a flapping airfoil using immersed boundary method

Abstract

The numerical simulation of flows past flapping foils at moderate Reynolds numbers presents two challenges to computational fluid dynamics: turbulent flows and moving boundaries. The direct forcing immersed boundary (IB) method has been developed to simulate laminar flows. However, its performance in simulating turbulent flows and transitional flows with moving boundaries has not been fully evaluated. In the present work, we use the IB method to simulate fully developed turbulent channel flows and transitional flows past a stationary/plunging SD7003 airfoil. To suppress the non-physical force oscillations in the plunging case, we use the smoothed discrete delta function for interpolation in the IB method. The results of the present work demonstrate that the IB method can be used to simulate turbulent flows and transitional flows with moving boundaries. transitional flows, moving boundary, immersed boundary method, smoothed discrete delta function

Numerical analysis on transitions and symmetry-breaking in the wake of a flapping foil

“…We will use the immersed boundary method [23][24][25][26][27] to numerically simulate Godoy-Diana et al's experiment and investigate the transition process from the KVS to the RKVS and its relation with thrust generation. Moreover, the numerical simulation offers some details of flow patterns, which are not available in experiments, so that the complete scenarios on flow patterns can be observed.…”

An implementation of the direct-forcing immersed boundary method using GPU power

“…With IBM, equations may be solved only on a Cartesian grid, and there is no need to reconstruct the grid in the case of moving or deforming bodies. Although the immersed boundary CONTACT Bulent Tutkun tutkun@itu.edu.tr method was first proposed and implemented by Peskin (1972) to simulate blood flow interacting with the heart, now it is in use for the solution of various problems, such as moving rigid boundaries (Liao, Chang, Lin, & Mcdonough, 2010), flapping airfoils (Yang, He, & Zhang, 2010), heat transfer (Luo, Zhuang, Fan, & Haugen, 2016), viscoelastic fluid (Lee & Wolgemuth, 2016), acoustic wave scattering (Seo & Mittal, 2011), natural convection (Dash & Lee, 2014), and separated turbulent flow (Bernardini, Modesti, & Pirozzoli, 2016). In his method, Peskin used Lagrangian points connected by springs to simulate the elastic boundary.…”