2024/12/13 by Xuerao He, Kengo Deguchi, He, Xuerao +5
Chemical Engineering · Engineering · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Thin Films #Fluid Dynamics and Vibration Analysis #Rheology and Fluid Dynamics Studies
paper · pdf · doi:10.48550/arxiv.2412.10037
openalex publication_date 2024/12/13 · openalex created_date 2024/12/17 · openalex updated_date 2026/07/28
Shear-thinning fluids flowing through pipes are crucial in many practical applications, yet many unresolved problems remain regarding their turbulent transition. Using highly robust numerical tools for the Carreau-Yasuda model, we discovered that linear instability can arise when the power-law index falls below 0.35. This inelastic non-axisymmetric instability can universally arise in generalised Newtonian fluids that extend the power-law model. The viscosity ratio from infinite to zero shear rate can significantly impact instability, even if it is small. Two branches of finite-amplitude travelling wave solutions bifurcate subcritically from the linear critical point. The solutions exhibit sublaminar drag reduction, a phenomenon not possible in the Newtonian case.