Generating wall-bounded turbulent inflows at high Reynolds numbers

One of the main challenges in simulating high Reynolds number ( italic Re Re ${\textit{Re}}$ ) turbulent boundary layers (TBLs) is the long streamwise distance required for large-scale outer-layer structures to develop, making such simulations prohibitively expensive. We propose an inflow generation method for high italic Re Re ${\textit{Re}}$ wall turbulence that leverages the known structure and scaling laws of TBLs. Pre-multiplied spectra of streamwise velocity show that with an increase in italic Re Re ${\textit{Re}}$ the outer region grows and occupies more of the spanwise wavenumber space in proportion to the increase in italic Re Re ${\textit{Re}}$ , while the inner region remains approximately the same. Exploiting this behaviour, we generate inflow conditions for a target italic Re Re ${\textit{Re}}$ by starting from cross-stream velocity slices at a lower base italic Re Re ${\textit{Re}}$ . In spectral space, we identify the inner- and outer-region wavenumbers, and shift the outer-region components proportionally to the desired italic Re Re ${\textit{Re}}$ increase. We examine the capability of this method by scaling velocity slices at italic Re Subscript theta Baseline equals 2240