Scopus
🔓 Açık Erişim
Direct numerical simulation of turbulent flow and structures in a circular pipe subjected to axial system rotation
Journal of Fluid Mechanics · Kasım 2024
Makale Bilgileri
DergiJournal of Fluid Mechanics
Yayın TarihiKasım 2024
Cilt / Sayfa1000
Scopus ID2-s2.0-85210965375
Erişim🔓 Açık Erişim
Özet
Turbulent circular pipe flows subjected to axial system rotation are studied using direct numerical simulations (DNS) for a wide range of rotation numbers of Rob = 0–20 at a fixed Reynolds number. To ensure that energetic turbulent eddy motions are captured at high rotation numbers, long pipes up to Lz = 180πR are used in DNS. Two types of energy-containing flow structures have been observed. The first type is hairpin structures that are characteristic of the turbulent boundary layer developing over the pipe wall for both non-rotating and axially rotating flows. The second type is Taylor columns forming at moderate and high rotation numbers. Based on the study of two-point autocorrelation coefficients, it is observed that Taylor columns exhibit quasi-periods in both axial and azimuthal directions. According to the premultiplied spectra, Taylor columns feature one single characteristic axial length scale at the moderate rotation numbers but two at high rotation numbers. It is discovered that the axial system rotation suppresses the sweep events systematically and impedes the formation of hairpin structures. As the rotation number is increased, the turbulence kinetic energy held by Taylor columns enhances rapidly associated with significant increases in their axial length scales.
Yazarlar (2)
1
Zhao Ping Zhang
2
Bing Chen Wang
Anahtar Kelimeler
pipe flow
rotating turbulence
turbulence simulation
Kurumlar
University of Manitoba
Winnipeg Canada
Metrikler
1
Atıf
2
Yazar
3
Anahtar Kelime