Wall-resolved Large-eddy simulation of flow past a grooved cylinder up to $Re_D=6\times 10^4$

We present wall-resolved, large-eddy simulations (LES) of flow past a groove-walled circular cylinder. Periodic span-wise boundary conditions are implemented with span up to $3\,D$. The stretched-vortex sub-grid scale model is utilized in the whole domain, including regions of large-scale separated flow. The circumferential cylinder surface comprises $32$ sinusoidal, span-wise groves of equal height $\epsilon$. For the first set of LES, with $Re_D=3.9 \times 10^3$ fixed and $0\le \epsilon \le 1/32$, some properties of the mean flow behave similarly to changes in the smooth-cylinder flow when $Re_D$ is increased, such as shrinking mean-flow recirculation length and near-constant pressure coefficient. A second set of LES uses fixed $\epsilon/D=1/32$ and varies $Re_D$ from $3.9 \times 10^3$ to $6 \times 10^4$, the latter value reaching the beginning of the transcritical flow regime. Comparison with experiment as well as wall-friction and Q plots, will be discussed.