Switch of tonal noise generation mechanisms in airfoil transitional flows

Abstract

Large eddy simulations are performed to study tonal noise generation by a NACA0012 airfoil for Reynolds numbers in the range $0.5\ifmmode\times\else\texttimes\fi{}{10}^{5}\ensuremath{\le}R\phantom{\rule{0}{0ex}}e\ensuremath{\le}4\ifmmode\times\else\texttimes\fi{}{10}^{5}$. Different flow patterns responsible for noise generation originate from laminar separation bubbles over the airfoil surface. Intermittency and flow transition to turbulence plays a key role in the noise spectrum.

Topics & Concepts