Sponsor
This work was supported by the Office of Naval Research (ONR) through grant numbers: N000141712649 and N000142012535 and was partially funded by the US National Science Foundation (grant no. 1652244). This work was carried out with resources of the Ad-vanced Research Computing at Hopkins (ARCH) core facility (rock-fish.jhu.edu), which was supported by the National Science Foundation (NSF) grant number OAC 1920103.
Published In
International Journal of Heat and Fluid Flow
Document Type
Article
Publication Date
5-27-2025
Subjects
Mechanical engineering, Turbulence -- Mathematical models
Abstract
The restricted nonlinear (RNL) model is employed as low-order representation of turbulent flow over riblets at π ππ β 395. Comparisons with direct numerical simulations (DNS) verify the ability of the model to accurately capture low-order statistics, as well as trends in drag-alteration and secondary motion as a function of riblet geometry and spacing. We demonstrate the ability of the RNL model to reproduce additional flow features by decomposing the roughness function to isolate contributions from the total stress and comparing its predictions to DNS data. An analysis of the spectra of Reynolds shear stress shows that the RNL model captures Kelvin- Helmholtz-like rollers linked to riblet drag reduction breakdown but slightly over predicts the total stresses. The reproduction of the overall trends in stresses and flow features linked to the breakdown of riblet induced drag-reduction suggests that the nonlinearity and scale interactions retained in the RNL system are adequate to capture the key mechanisms underlying turbulent flow over a range of riblet geometries. These results also indicate that examining the limitations of the model may provide insight into the critical nonlinear interactions underlying drag alteration due to riblets.
Rights
Β© 2025 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license http://creativecommons.org/licenses/by/4.0/
DOI
10.1016/j.ijheatfluidflow.2025.109862
Persistent Identifier
https://archives.pdx.edu/ds/psu/43680
Citation Details
Zhu, X., Viggiano, B., Minnick, B. A., & Gayme, D. F. (2025). Restricted nonlinear simulations of flow over riblets: Characterizing drag reduction and its breakdown. International Journal of Heat and Fluid Flow, 116, 109862.
Description
See the additional file for the dataset (zipped folder) as of 6/3/2025, or access the files via Github; dataset link: https://github.com/lesgo-jhu/lesgo