Dynamic mode decomposition of gas-liquid flow in a rotodynamic multiphase pump

摘要

Rotodynamic multiphase pump is vital for energy conversion and oil-gas exploitation. In the present work, the complicated transient characteristics of gas-liquid two phase flow in a multiphase pump under 10% and 20% inlet GVFs are investigated by Dynamic Mode Decomposition (DMD). Results show that the strip-shaped gas volume develops in impeller and then leads to jet impingement at diffuser inlet, which induces the inception of gas pocket in diffuser passage. The major vortex structures in the multiphase pump consist of leading edge vortex in impeller and diffuser, separation vortex in impeller, tip leakage vortex in impeller, trailing edge vortex in impeller and diffuser. Dynamic modes under significant frequency show that, the main structures are the radial inhomogeneity near pressure side in impeller, and the back flow phenomenon near suction side in diffuser. (C) 2019 Elsevier Ltd. All rights reserved.