Research on spatial filtering velocity measurement method of interdigital electrostatic sensor

2021 ◽  
Author(s):  
Heming Gao ◽  
susu zhong
Keyword(s):  
Velocity Measurement ◽  
Flow Simulation ◽  
Quantitative Relationship ◽  
Spatial Filtering ◽  
Peak Frequency ◽  
Repeated Measurements ◽  
Spatial Position ◽  
Solid Particles ◽  
Two Phase ◽  
Relative Standard

Abstract Particle velocity is an important parameter to describe the flow characteristics of gas-solid two-phase flow, and it is also a tricky problem for the parameter measurement of gas-solid flow. Aiming at the problem that the spatial filtering effect of electrostatic sensor suffering from the effect of spatial distribution of solid particles, a new type of interdigital electrostatic sensor is proposed to resolve it. Firstly, the spatial filtering characteristics of the interdigital electrostatic sensor are analyzed through finite element simulation, obtained that the spatial position and size of the solid particles have no effect on the peak frequency of the sensor output signal power spectrum, and the quantitative relationship between the velocity and peak frequency is derived. Then the experimental verification is carried out on an experimental platform of gravity conveying particle flow. Simulation and experimental results show that the interdigital electrostatic sensor eliminates the influence of particle spatial position and particle size on the velocity measurement results. In the velocity range of 2.97m/~4.95m/s, the relative error of the measurement system is better than 5%, and the relative standard deviation of repeated measurements is within 3%.

A Lagrangian Vortex Method for Two-Phase Particulate Flow Simulation

2007 ◽  
Author(s):  
A. Gharakhani
Keyword(s):  
Concentration Field ◽  
Flow Simulation ◽  
Particle Method ◽  
Vortex Method ◽  
Solid Particles ◽  
Two Phase ◽  
Benchmark Tests ◽  
Particle Momentum ◽  
Conservation Of Momentum ◽  
Two Fluid

The Lagrangian vortex method developed by Chen and Marshall [1] for two-way coupled two-phase flow simulation of (cloud of) solid particles is revisited in this paper. The algorithm attempts to merge the best attributes of the Lagrangian and two-fluid continuum models into one by applying the Lagrangian conservation of momentum simultaneously with the conservation of the concentration field along the trajectories of the particle clouds. In this paper, a consistent implementation is proposed, which is considerably less complicated and computationally more stable than the original formulation. In particular, it is shown that when a smooth particle representation of the concentration field is used, the Lagrangian conservation of particle momentum automatically satisfies conservation of the concentration field. This implies that the evaluation of the concentration field becomes a post-processing exercise as is common with the traditional Lagrangian (solid) particle method, although the new method yields much smoother concentration fields. In this paper the formulation for the modified approach, as well as results from basic benchmark tests are presented.

Turbulent Impinging Flow Simulation for High-Level Waste Storage and Processing Applications

2007 ◽  
Author(s):  
S. Rhea ◽  
M. Fairweather
Keyword(s):  
Fluid Dynamic ◽  
Flow Simulation ◽  
Turbulent Jets ◽  
Solid Particles ◽  
High Level Waste ◽  
Data Sets ◽  
Two Phase ◽  
Stagnation Line ◽  
Waste Storage ◽  
High Level

The efficient storage and processing of high-level nuclear waste could be improved by a better understanding of the behaviour of the particle-laden fluid flows involved. This work reports a mathematical modelling study of impinging single- and two-phase turbulent jets that is of relevance to the flows used industrially to prevent the settling of solid particles in storage tanks, and to re-suspend particles that form a bed. A computational fluid dynamic model, that embodies a Lagrangian particle tracking technique, is applied to the prediction of these flows. Predictions in the free flow and wall regions, and along the stagnation line, of the single-phase flow are in reasonable accord with data, although the addition of particles results in less satisfactory agreement between predictions and measurements. The influence of particles is, however, reproduced qualitatively by the mathematical model, with quantitative differences attributable to a lack of particle drag in the simulations. Uncertainties in experimental parameters may be responsible for some of the differences between predictions and data, and examination of the data used casts doubts on its reliability. Further work is required in terms of the use of more advanced turbulence modelling techniques, and the provision of detailed and reliable data sets.

scholarly journals Research on the Dynamic Responses of Simply Supported Horizontal Pipes Conveying Gas-Liquid Two-Phase Slug Flow

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 83
Author(s):  
Gang Liu ◽  
Zongrui Hao ◽  
Yueshe Wang ◽  
Wanlong Ren
Keyword(s):  
Slug Flow ◽  
Peak Frequency ◽  
Dynamic Responses ◽  
Piping System ◽  
Transverse Displacement ◽  
Vibration Acceleration ◽  
Two Phase ◽  
Horizontal Pipes ◽  
Simply Supported ◽  
Superficial Gas Velocity

The dynamic responses of simply supported horizontal pipes conveying gas-liquid two-phase slug flow are explored. The intermittent characteristics of slug flow parameters are mainly considered to analyze the dynamic model of the piping system. The results show that the variations of the midpoint transverse displacement could vary from periodic-like motion to a kind of motion whose amplitude increases as time goes on if increasing the superficial gas velocity. Meanwhile, the dynamic responses have certain relations with the vibration acceleration. By analyzing the parameters in the power spectrum densities of vibration acceleration such as the number of predominant frequencies and the amplitude of each peak frequency, the dynamic behaviors of the piping system like periodicity could be calculated expediently.

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