Flow Velocity Field Measurement of Vertical Upward Oil–Water Two-Phase Immiscible Flow Using the Improved DPIV Algorithm Based on ICP and MLS

Abstract

Flow velocity field measurement is important for analyzing flow characteristics of oil-water two-phase immiscible flow in vertical well. Digital particle image velocimetry (DPIV) is an effective velocity field measurement method that has overcome single point measurement limitation of traditional instruments. However, multiphase flow velocity fields generated by DPIV are often accompanied by local false vectors caused by image mismatching, which leads to measurement results with low accuracy. In this paper, the reasons for oil-water two-phase immiscible flow image mismatching in inner diameter 125 mm vertical pipe is identified by studying the DPIV calculation process. This is mainly caused by image noise and poor window following performance that results from poor deformation performance of the interrogation window. To improve deformation performance of the interrogation window, and thus improve the accuracy of the algorithm, iterative closest point (ICP) and moving least squares (MLS) are introduced into the window deformation iterative multigrid algorithm in DPIV postprocessing algorithm. The simulation showed that the improved DPIV algorithm had good matching performance, and thus the false vector was reduced. The experimental results showed that, in light of the present investigation, on average, the improved DPIV algorithm is found to yield an accuracy improvement of~6%; the measurement uncertainty and reproducibility of the improved DPIV algorithm were 0.149 × 10 −3 m/s and 1.98%, respectively.

Optimization of the Hollow Rectification Sill in the Forebay of the Pump Station Based on the PSO‐GP Collaborative Algorithm

“…Finally, the established PSO-GP model was used as the fitness evaluation plan of the PSO algorithm to optimize the hollow rectification sill of the forebay of the pump station. For the optimized rectification sill, physical model test [43,44] and DPIV measurement technology were used [33,[45][46][47] to verify the validity and engineering practicability of the PSO-GP model in optimizing the design of the hollow rectification sill of the forebay of the pump station.…”