DNS of Complete Transition to Turbulence via Oblique Breakdown at Mach 3: Part II

Detailed Comparison of DNS with PSE for Oblique Breakdown at Mach 3

“…Similar computations for first-mode type waves in a Mach 4.5 boundary layer were reported earlier by Jiang et al 18 The present paper complements the study by Mayer et al 11,12,14 via one additional DNS computation. In the earlier investigations, Mayer et al 11,12,14 assumed symmetry with respect to the spanwise direction to reduce computational costs. In order to ensure that this assumption is indeed valid, a new DNS has been conducted in which the artificial symmetry restriction was removed.…”

“…DNS results of the complete transition process as discussed in this paper, together with Mayer et al 11,12 and von Terzi et al, 14 constitute a valuable and extensive database that can be utilized for the validation of several different engineering tools across the various stages of transition. With the development of LASTRAC, NASA Langley Research Center aims to create an integrated tool kit that can be employed for conventional N-factor calculations (based on LST or PSE) and more sophisticated simulations from the receptivity process to the early nonlinear transition stages.…”

“…A nonlinear transition mechanism, however, can only be considered to be an important physical mechanism if it can initiate the entire transition process of a laminar boundary layer to turbulence. This issue was addressed by the final part of the series of numerical studies, 11,12,14 where the entire transition path of oblique breakdown for a flat-plate boundary layer at Mach 3 was simulated. Similar computations for first-mode type waves in a Mach 4.5 boundary layer were reported earlier by Jiang et al 18 The present paper complements the study by Mayer et al 11,12,14 via one additional DNS computation.…”

“…This issue was addressed by the final part of the series of numerical studies, 11,12,14 where the entire transition path of oblique breakdown for a flat-plate boundary layer at Mach 3 was simulated. Similar computations for first-mode type waves in a Mach 4.5 boundary layer were reported earlier by Jiang et al 18 The present paper complements the study by Mayer et al 11,12,14 via one additional DNS computation. In the earlier investigations, Mayer et al 11,12,14 assumed symmetry with respect to the spanwise direction to reduce computational costs.…”

“…In order to ensure that this assumption is indeed valid, a new DNS has been conducted in which the artificial symmetry restriction was removed. Furthermore, the original symmetric simulation of Mayer et al 11,12,14 was continued and additional time-dependent data were saved in order to extend the interval for the time average and, hence, to ensure the convergence of statistical quantities.…”