Angular momentum transport and its scaling in co-rotating suspension Taylor-Couette flow

¹ Engineering Mechanics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, India
² Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, 28359 Bremen, Germany

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Published online: 1 December 2025

Abstract

Torque measurements are carried out to elucidate the global response of a neutrally buoyant, non-colloidal suspension in the co-rotation regime (i.e., the rotation ratio Ω = ω_o/ω_i > 0, with ω_o and ω_i being the angular speeds of the inner and outer cylinders, respectively) of Taylor-Couette flow (TCF) up to a shear Reynolds number of Re_s ≤ 1000 and particle volume fraction of ϕ ≤ 0.2. The dimensional torque increases with increasing particle loading for all Ω ≤ 0.65, however, the maximum of dimensionless angular momentum (pseudo Nusselt number) occurs at intermediate values of Ω ∈ (0.3, 0.5), depending on the values of Re_s and ϕ. The pseudo-Nusselt number in the co-rotation regime is found to follow the master scaling relation proposed by Alam and Ghosh [Phil. Trans. R. Soc. A 381, 20220226 (2023)] in the counter-rotation regime (Ω < 0). The e↵ect of co-rotation on torque scaling is also discussed.