Model for Predicting Solids Velocity Fluctuations in Sedimenting Suspensions

Abstract

Computational fluid dynamics (CFD) simulations of sedimenting suspensions in two‐dimensional periodic domains using a Eulerian two‐fluid model were performed with the commercial software ANSYS Fluent®. Three particle systems belonging to Geldart groups A and B were selected to gather data on the solids velocity fluctuations. It is proposed that solids velocity fluctuations are composed of local and global parts. Therefore, the solids velocity signal was segregated into low‐frequency and high‐frequency fluctuations using the FFT solver in MATLAB®. A model is proposed to predict the velocity fluctuations of a solid phase at low volume fractions and the model results are compared with the CFD results. The model is capable of capturing the solid particles fluctuation in the dilute limit.

Pressure pulsation test of Wanjiazhai Francis turbine at different loads

“…In addition to the time-domain characteristics of pressure pulsation, frequency characteristics are also the focus of scholars' research. Fast Fourier transform(FFT) [10] can conveniently obtain the frequency components of signals and is a commonly used data processing method.…”

Analysis of Flow Fluctuation of Confined Backward-Facing Step Based on Pulsation Tracking Network Method

“…In this paper, the numerical simulation of restricted backward step flow in reference [9] is carried out, and a large number of monitoring points are arranged on its longitudinal section to obtain the local velocity and pressure fluctuation information, and the results are processed by FFT [10]. The main frequency distribution and amplitude distribution corresponding to the main frequency of velocity fluctuation and pressure fluctuation are analyzed.…”