Investigation of vortex shedding from an airfoil by CFD simulation and computer-aided flow visualization

Novak, Lovrenc (author), Bajcar, Tom (author), Širok, Brane (author), Orbanić, Alen (author), Bizjan, Benjamin (author)

The article presents an experimental and numerical study of vortex generation and shedding from a NACA 4421 airfoil at low Reynolds number. The experiment was conducted in a low-speed wind tunnel by flow visualization. A high-speed camera was used to record flow structures at the airfoil trailing edge. The recorded images were processed with an in-house developed software based on the advection-diffusion equation to compute instantaneous 2D velocity fields. These results were compared with results of the CFD simulation which employed the scale-adaptive simulation (SAS) turbulence modelling. The SST-SAS model produced finer and less stable turbulent structures compared to an URANS simulation with the SST model. Time-averaged velocities and frequency spectra for the both models are in good agreement, but variability of flow in both time and frequency domain is higher in case of the SST-SAS model. Velocity fields computed on the basis of visualization show generally acceptable agreement with the CFD results. Higher errors occur in areas of unperturbed smoke trails and areas of high velocity gradients, however, the vortex shedding frequency is captured with excellent agreement to the experiment.

• Language: English
• Keywords: CFD, flow visualization, airfoil aerodynamics, vortex street, scale adaptive simulation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2018
• Number of pages: Str. 3023-3033
• Numbering: Vol. 22, iss. 6B
• PID: 20.500.12556/RUL-126380
• UDC: 532:629.7:533.6.04:519.61/.64(045)
• ISSN on article: 0354-9836
• DOI: 10.2298/TSCI170615002N
• COBISS.SI-ID: 15955995
• Publication date in RUL: 19.04.2021

Record is a part of a journal

• Title: Thermal science
• Shortened title: Therm. sci.
• Publisher: Vinča Institute of Nuclear Sciences
• ISSN: 0354-9836
• COBISS.SI-ID: 43417089

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
• Licensing start date: 19.04.2021

Secondary language

• Language: Slovenian
• Keywords: računalniška dinamika tekočin, vizualizacija toka, aerodinamika krila, vrtinčna steza, SAS model turbulence