Study on the Gas-liquid Flow Characteristics in the Reversing Bucket of Water Jet Propulsion

Abstract

To investigate the gas-liquid two-phase flow characteristics in the reversing bucket of water jet propulsion, the numerical simulations based on the Euler-Euler inhomogeneous model was conducted to the internal flow field of the reversing bucket under 1%~12% different inlet gas volume fractions (α). Based on that, the gas distribution, gas-liquid velocity streamlines and thrust changing were obtained to discuss the gas-liquid flow characteristics and the influence on the thrust of the reversing bucket. The calculation results show that the gas mainly distributes in the inner part of the reversing bucket flow passage under different inlet gas volume fractions. On the condition that the inlet gas volume fraction is more than 2%, the gas accumulation has occurred in the inlet section of the flow passage. With the increasing of inlet gas volume fraction, average velocity and pressure increase gradually at each cross-section of reversing bucket flow passage, and at the higher gas concentration in each cross-section, where the vortex will exist, indicating that the gas concentration has a great relationship with the vortex aggregation in the reversing bucket flow passage. When the inlet gas volume fraction is 7%, the thrust reaches the maximum. It shows that the appropriate gas can effectively improve the thrust efficiency of the reversing bucket.