Energy Characteristics of Full Tubular Pump Device with Different Backflow Clearances Based on Entropy Production

In this study, the entropy theory was used as evaluation standard of energy dissipation, and effect backflow clearance (the gap between motor rotor shell) on characteristics a full tubular pump investigated by 3D unsteady flow simulation. The calculated results validated through testing shows that produces additional head loss rotation requires more shaft power. losses lead to significant decline in efficiency device. Under design conditions, total dissipation clearance, rear guide vane, outlet passage decreases with increase radius, but impeller first then rises radius. addition, radius leads disorderly pattern impeller. rate suction side near inlet increases vane wall This work can provide an intuitive analysis caused reference for engineering applications pump.