双层改进型推进式桨转速对槽内流场的影响OA

To optimize the energy utilization efficiency and mixing performance of industrial mixing tank while addressingthe problem of flow field separation and circulation efficiencyreduction caused by improper rotational speeds,the research team investigated the complex flow field characteristics generated by a double-layer modified propeller blade within a mixing tank.By constructing an improved propeller blade structure comprising four sections(where the first section and the third section form a 160°angle with the second section respectively,the second section is horizontally perpendicular to the hub,and the fourth section bent downward at 20°on the basis of the third section),combined with Particle Image Velocimetry(PIV)experiments and Large Eddy Simulation(LES)numerical calculationsmethod,the research team systematically analyzed flow field characteristics,velocity distributions and turbulent kinetic energy transfer mechanisms at four distinct mixing rotational speeds.The results show that mixing rotational speed decisively influences on the connection of upper and lower blade flow fields and the overall circulation pattern within the tank.At mixing rotational speed N=140 r/min,optimal flow field connection occurs between upper and lower blades,forming a single integrated circulation within the channel with near-complete elimination of low-speed vortex regions.However,increasing mixing rotational speed to N=160 r/min shifts the vortex centers of upper and lower blades approximately move to the right by 10%and 20%,respectively,causing flow field separation and reducing circulation efficiency.High turbulent kinetic energy regions are concentrated near the blades.Increasing rotational speed enhances turbulent kinetic energy transfer,but the increase of turbulent kinetic energy is limited when the mixing rotational speed Nexceeds 140 r/min.PIV experimental results are in good agreement with LES simulation outcomes,validating the reliability of the numerical model.These findings provide referencefor optimizing the design of industrial mixing equipment.