Large eddy simulation study of a Venturi cavitation nozzle with two auxiliary flow channels

Abstract Cavitating jet nozzles play a crucial role in various industries, including oil and gas exploration, cleaning and cutting, and the automotive sector. This study introduces a Venturi cavitation nozzle with two auxiliary flow channels (VWC), derived from the traditional Venturi cavitation nozzle (VN). The flow field of the nozzle is numerically analyzed using the large eddy simulation (LES) and the Zwart–Gerbera–Belamri (ZGB) cavitation model, and the results are compared with those of the traditional VN. This study examines the transient steam distribution and its variation within the two nozzles in the low-pressure range, assessing the influence of minor inlet pressure fluctuations on the internal cavitation flow. Under high-pressure conditions, the jet length and the velocity at the end of the external domain were compared, and the velocity of each section and the velocity change trend of the nozzle outlet and the end of the external flow field in the high-pressure range were analyzed. The numerical results demonstrate that the VWC exhibits enhanced vapor generation and jet performance under identical boundary conditions. In terms of steam generation, the vapor content of the VWC is consistently higher than that of the VN, with a maximum difference of 25 %. Regarding jet strength, under the same pressure, the VWC exhibits a lower axial jet velocity decay rate than the VN, which can be reduced by up to 52.8 %. Additionally, the longitudinal jet velocity of the VWC is slightly higher, surpassing that of the VN by up to 52 %. This research offers valuable insights and a novel reference for advancing the structural design of cavitation nozzles.