Recent Progress in Modelling the Incompressible and Compressible Wall-Bounded Turbulence
Seminar
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Date
30 Jan 2023
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Organiser
Department of Aeronautical and Aviation Engineering
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Time
11:00 - 12:00
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Venue
Enquiry
General Office aae.info@polyu.edu.hk
Remarks
Meeting ID: 925 6034 0727 | Passcode: 752912
Summary
Abstract
In this talk, we will focus on the physics and modelling of the incompressible and compressible wall-bounded turbulence. Firstly, for incompressible wall turbulence, we develop a new methodology to assess the streamwise inclination angles (SIAs) of the wall-attached eddies populating the logarithmic region with a given wall-normal height. The present results show, for the first time, that the SIAs of attached eddies are Reynolds-number dependent in low and medium Reynolds numbers and tend to saturate at 45o as the Reynolds number increases. These findings clarify the long-term debate and perfect the picture of the attached-eddy model. Secondly, we will present our recent efforts in modelling the compressible wall-bounded turbulence. The extension of incompressible wall model to high-speed flows is accommodated by proposing a novel transformation, which maps the mean velocity profiles of compressible wall turbulence to the incompressible law of the wall. The performance of the transformation is verified for compressible wall-bounded flows with edge Mach numbers ranging from 0 to 15 and friction Reynolds numbers ranging from 200 to 2000. (Ref. PNAS 2021, JFM 2021, JFM 2022, etc.)
Speaker
Dr Lin Fu is an Assistant Professor in the Department of Mathematics and the Department of Mechanical and Aerospace Engineering at The Hong Kong University of Science and Technology (HKUST). Before he joined HKUST, he was a Postdoctoral Fellow working with Prof. Parviz Moin at Center for Turbulence Research (CTR), Stanford University, for more than 3 years. He also did postdoctoral research with Prof. Nikolaus Adams at Technical University of Munich, where he obtained his PhD degree with a grade of Summa Cum Laude (passed with the highest distinction). His research is funded by the Research Grants Council (RGC) of Hong Kong with the recognition of Early Career Award. He has published more than 45 journal papers on PNAS, JFM, PRF, JCP, CMAME, etc.