Large-eddy simulation of turbulent flows in a heated streamwise rotating channel

The mechanism underlying the magnitude-reverse phenomenon of the mean spanwise velocity with respect to an increasing rotation number in a streamwise-rotating channel flow is investigated through a budget balance analysis of Reynolds shear stress ⟨u2′u3′⟩. It is found that ⟨u2′u3′⟩ imposes a negative feedback to itself through the production term, which prevents its magnitude from increasing monotonically with an increasing rotation number. This behavior of ⟨u2′u3′⟩ further leads to the magnitude reverse in the spanwise wall shear stress and mean spanwise velocity in the near-wall region.

show abstract

Helicity budget in turbulent channel flows with streamwise rotation

Yan

2022

Physics of Fluids

View full text Add to dashboard Cite

The streamwise rotation effects in turbulent channel flows are reflected not only in the appearance of the secondary flows, but also the weakened streamwise velocity and spanwise vorticity. In this paper, we investigate the secondary flows from three perspectives: the mean spanwise velocity, the mean streamwise vorticity, and combined mean and fluctuating helicity. We found that the combined helicity is also an alternative perspective to characterize the streamwise rotation effect, especially for the secondary flows. The budget equations of the mean and fluctuating helicity in physical space are derived theoretically and analyzed numerically. The streamwise rotation effects on the secondary flows are directly reflected on the pressure and Coriolis terms, which provides an essential source for helicity within the near-wall regions. The production term could be decomposed into two terms, which originate from the momentum and vorticity equations, respectively. The helical stress (velocity-vorticity correlation) originating from the vorticity equation shows a simple profile distribution, and is dominant for the production for the helicity within the near-wall regions. The high helical structures in the core regions can be explained as an intense wall-normal transportation, which transfers produced helicity within the near-wall regions into the core regions.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Large-eddy simulation of turbulent flows in a heated streamwise rotating channel

Abstract: In this thesis, large-eddy simulation has been performed to investigate a heated plane channel flow subjected to streamwise system rotations. A variety of rotation num-

Cited by 3 publications

References 62 publications

Assessment of the performances of sub-grid scalar flux models for premixed flames with different global Lewis numbers: A Direct Numerical Simulation analysis

Assessment of the performances of sub-grid scalar flux models for premixed flames with different global Lewis numbers: A Direct Numerical Simulation analysis

On the self-constraint mechanism of the cross-stream secondary flow in a streamwise-rotating channel

Helicity budget in turbulent channel flows with streamwise rotation

Contact Info

Product

Resources

About