Coriolis-induced asymmetry in drag mechanisms of rotating ribbed channels

Drag generation in rotating ribbed channels is governed by the interplay between rib-induced separation and Coriolis-driven momentum redistribution, which breaks drag symmetry between opposing walls. In variable-density flows, centrifugal pressure gradients couple with hydrodynamic pressure losses, impeding accurate assessment of rotational flow resistance. This study establishes a rotational pressure correction model accounting for temperature–density coupling, decoupling centrifugal pressure effects. Validation against high-fidelity simulations yields a maximum error of ∼0.38%. Using this model with large eddy simulation, we investigate flow resistance in a bilaterally ribbed square channel at Re = 30 000 and Ro = 0–0.4. Results indicate rotation significantly augments flow resistance; increasing Ro to 0.4 elevates the friction factor by 17.35%. Physically, rotation disrupts flow symmetry: a Coriolis-induced velocity deficit near the trailing side deflects the mainstream toward the leading side. The trailing-wall-directed Coriolis force exacerbates fluid impingement on ribs, causing pressure drag to surge and dominate. Conversely, the Coriolis effect near the leading side suppresses turbulent fluctuations, mitigating local pressure loss. Furthermore, flow resistance sensitivity to rotation is modulated by rib topology. Rib height dictates momentum exchange intensity by altering effective cross section and local velocity, whereas rib pitch governs Reynolds stresses by regulating inter-rib separation–reattachment. These findings offer physical insight into drag mechanisms, establishing a theoretical basis for optimizing rotating turbulated channels.