Flow characteristics of gas-containing water in shielded gaps

This study investigated the flow characteristics of fluids within the narrow annular gap of a canned motor rotor, specifically focused on a 15-mm-wide rotor gap. By varying the inlet fluid flow rates and gas injection volumes, the formation of Taylor vortices and gas blockage phenomena under operational conditions are examined. Experimental observations confirm the emergence of Taylor–Couette flow within the annular region. Gas bubbles are entrained by the vortex structures, forming continuous helical gas bands that migrate toward the outlet. Due to buoyancy effects, phenomena such as bubble migration, gas band splitting, and recombination are observed, depending on the flow direction of the fluids. Under critical conditions, gas accumulation in the upper region of the gap leads to the onset of gas blockage, which may significantly affect flow stability and cooling performance. These results will offer a theoretical and experimental basis that serves as a foundation for optimizing the operational efficiency of canned motors.