Characteristics of pressure distribution and skin friction within the laminar separation bubble at different Reynolds numbers

Donghwi Lee, Soshi Kawai, Taku Nonomura, Akira Oyama, Kozo Fujii

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Mechanisms behind the pressure distribution within a laminar separation bubble (LSB) are investigated by largeeddy simulations around a 5% thickness blunt flat plate. The plate length based Reynolds numbers are set to be (Re c ) 5.0 × 10 3 , 6.1 × 10 3 , 8.0 × 10 4 , 1.1 × 10 4 , and 2.0 × 10 4 . From the results, two types of LSB are observed; steady laminar separation bubble (LSB-S) at Re c = 5.0 × 10 3 and 6.1 × 10 3 , and a steady-fluctuating laminar separation bubble (LSB-SF) at Re c = 8.0 × 10 3 , 1.1 × 10 4 , and 2.0 × 10 4 . As the Reynolds number increases, different shapes of pressure disribution appear such that a gradual pressure recovery in the LSB-S and a plateau pressure distribution followed by a rapid pressure recovery in the LSB-SF. The reasons of appearing the different shapes of pressure distributions depending on the Reynolds number are explained by deriving the Reynolds averaged pressure gradient equation. From the momentum budgets of the equation, it is confirmed that the viscous stress near the surface has an influence on determining the different shape of pressure distribution. The different viscous stress distributions near the surface are affected by grwoth of the separated laminar shear layer depending on the Reynolds number or generation of the Reynolds shear stress.

Original languageEnglish
Title of host publication9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
PublisherTSFP-9
ISBN (Electronic)9780000000002
Publication statusPublished - 2015 Jan 1
Externally publishedYes
Event9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015 - Melbourne, Australia
Duration: 2015 Jun 302015 Jul 3

Publication series

Name9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
Volume1

Other

Other9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
CountryAustralia
CityMelbourne
Period15/6/3015/7/3

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

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