Abstract
Reducing skin friction has a key role in the efficiency of rail, highway, and airway transport vehicles or naval systems such as ships and underwater vehicles. In recent years, there is a growing interest in investigating turbulent drag-reducing capabilities of dimpled surfaces, which have great potential as a passive solution, while there still exists highly conflicting views and drag reduction rates reported in the literature as well as a lack of information about the drag reduction mechanism. In this study, large-eddy simulations (LES) were performed to investigate the characteristics and physical mechanism of the fluid flow over dimpled surfaces in a fully developed channel flow. The Reynolds number based on the channel height and the mean bulk velocity was nearly 5600 for all cases examined. Within the framework of the study, various dimple depth to diameter ratios as well as different dimple arrangements and geometries were considered. The detailed mean and instantaneous flow fields, turbulent kinetic energy budget and spectral characteristics of the flow are presented. The study revealed the potential of the dimpled surface in reducing skin friction and provided critical information about the flow features affecting the performance of the dimples.
| Original language | English |
|---|---|
| Article number | 2186415 |
| Journal | Journal of Turbulence |
| Volume | 24 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 2023 |
Bibliographical note
Publisher Copyright:© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Funding
The computational work was carried out during the first author’s research study visit to the University of Strathclyde, which was sponsored by TÜBİTAK. The work was also supported by the Scientific Research Projects Coordination Unit of ITU (ID: MDK-2018-41461). The work was also supported by the Scientific Research Projects Coordination Unit of ITU (ITU-BAP), (ID: MDK-2018-41461). The authors gratefully acknowledge the valuable comments, discussions and support by Prof. Mehmet Atlar of the University of Strathclyde during the preparation of this work. The computational simulations presented in this paper were conducted at National Centre for High-Performance Computing (UHeM) of Istanbul Technical University (ITU) and Research Computing for the West of Scotland regional supercomputer centre (ARCHIE-WeSt) at the University of Strathclyde. The post-processing of the data was performed at the Computational Ship Hydrodynamics Laboratory (ID: BC03F509614) of ITU. The computational work was carried out during the first author’s research study visit to the University of Strathclyde, which was sponsored by TÜBİTAK. The work was also supported by the Scientific Research Projects Coordination Unit of ITU (ID: MDK-2018-41461).
| Funders | Funder number |
|---|---|
| ARCHIE-WeSt) at the University of Strathclyde | BC03F509614 |
| University of Strathclyde | |
| International Technological University | |
| Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | |
| Istanbul Teknik Üniversitesi | |
| Bilimsel Araştırma Projeleri Birimi, İstanbul Teknik Üniversitesi | MDK-2018-41461 |
Keywords
- LES
- channel flow
- dimple
- drag reduction
- skin friction