Quantifying Flow Generated by Large Arrays of Oscillating 2D Airfoils

Oscillating or rotating airfoil arrays at distinct frequencies, are ubiquitous in natural systems and engineering applications, including flow control, wave mitigation, biological swarms, advanced cooling, and energy harvesting. Computation of large arrays of moving airfoils is often restricted by the limitations due to the mesh deformation during airfoil movement and increase in computational cost due to large number of airfoils. Due to these computational limitations, previous research on oscillating arrays has typically been restricted to relatively small arrays (< 10) oscillating objects, with the oscillation amplitude. In this study, we introduce a novel framework utilizing the Schwarz-Spectral Elements Method (Schwarz-SEM). This framework offers several key advantages: it simplifies meshing, requires fewer elements for accurate representation, and its ability to handle dynamic meshes makes it ideal for modeling oscillating systems at arbitrarily high oscillation amplitude. The framework achieves spectral accuracy, enabling highly detailed resolution of the underlying vortex generation process, which is necessary for comprehensive quantification of the turbulence structure. Our research demonstrates the scalability of this model, allowing for the simulation of up to 39 oscillating airfoils across a Reynolds number up to 5000, with each airfoil capable of being controlled independently. This showcases the model's significant potential for wake characterization studies, and future work will focus on capturing detailed wake characteristics and extending these studies to three dimensions. Analysis of turbulent kinetic energy, spectral features, and other high-order statistics provides insights into how the wake characteristics depend on the number and spatial arrangement of the vortex-generating airfoils.