Effect of the tip clearance on tip leakage vortex and pressure fluctuation characteristics in a helico-axial flow multiphase pump

Tip clearance inevitably exists in helico-axial flow multiphase pumps, which generates a great impact on characteristics. To select reasonable tip and improve the transporting efficiency, different clearances (Rtc = 0.5, 1.0, 1.5 mm) are chosen to investigate behaviors hydraulic Based shear stress transport k-ω turbulence model, unsteady Reynolds averaged Navier–Stokes equations applied solve flow. Results show that when increases, leakage vortex (TLV) near gradually becomes obvious pressure fluctuation TLV also larger. The spatial–temporal evolution is divided into three stages: split stage, contraction recurrence stage. Besides, rotor–stator interaction still primary cause for fluctuation.