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A series of interactive experiments are conducted to analyze the drag reduction technology with a rotating disk apparatus that combines microgroove structure and drag‐reducing additives including polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and sodium salicylate (NaSal). By varying the disk type, concentration of drag‐reducing additives, temperature, and Reynolds number (Re), the corresponding drag reduction rates are obtained effectively. The experimental results indicate that adding CTAC strengthens the heat degradation and shear resistance of PEO; while PEO can enhance the ability of CTAC to form micellar structures and balance energy distribution at low concentrations. Moreover, the synergistic effect of these two additives presents a better drag reduction performance with a maximum drag reduction rate of 24.1%; while the microgroove structure enhances the effect of active drag reduction. Therefore, the combination of active and passive drag reduction technology broadens the application of energy saving and consumption reduction in hydraulic rotating machinery. [ABSTRACT FROM AUTHOR]

In the practical application of hydraulic rotating machinery, it is essential to thoroughly explore drag reduction and rheological characteristics of drag-reducing additives to optimize machinery efficiency and reduce equipment consumption. This paper combines simulation and experimental approaches to investigate the drag-reduction performance and rheological properties of drag-reducing additives. Numerical simulations are initially conducted to investigate the shear-thinning properties of drag-reducing fluid and explore variations in drag-reduction rate. Turbulent phenomena characteristics are described by analyzing turbulent statistical quantities. Subsequently, the rheological behaviors of polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and their mixed solutions under different conditions are scrutinized using a rotational rheometer. The findings indicate that the drag reduction effect amplifies as the rheological index n and characteristic time λ decrease. The numerical simulations show a maximum drag reduction rate of 20.18%. In rheological experiments, a three-stage viscosity variation is observed in single drag-reducing additives: shear thickening, shear thinning, and eventual stabilization. Composite drag-reducing additives significantly reduce the apparent viscosity at low shear rates, thereby strengthening the shear resistance of the system. [ABSTRACT FROM AUTHOR]