Analysis of Airflow Velocity Field Characteristics of an Oat Cleaner Based on Particle Image Velocimetry Technology

2019 ◽  
Vol 35 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Xinping Li ◽  
Jialiang Zhang ◽  
Jiangtao Ji
Keyword(s):  
Particle Image Velocimetry ◽  
Velocity Field ◽  
High Speed ◽  
Radial Direction ◽  
Particle Image ◽  
Longitudinal Section ◽  
Airflow Velocity ◽  
Cleaning Performance ◽  
Image Velocimetry ◽  
Cleaning Machine

Abstract.To improve the cleaning performance of oat sorting devices with a single-fan three-cylinder screen system, this study investigated the airflow velocity field of a cleaning machine using particle image velocimetry (PIV) technology. Specifically, an optimal cleaning performance can be described as one with no material idling under the optimal operating parameters of the oat cleaning machine, the measured airflow velocity field space is divided into nine representative longitudinal planes that can reflect airflow velocity characteristics in the longitudinal plane. The results showed that a phenomenon of airflow backflow occurred in the radial direction above the medium cylinder screen, the airflow velocity in each longitudinal section of the airflow velocity field was less uniform in the transverse distribution, a. The movement of oat extracts in the cleaning room was recorded by a high-speed digital video camera. The phenomenon of oat impurities moving along the airflow backflow direction, and a transverse flow irregularity appearing in the radial direction above the medium cylinder screen were observed. The grain loss rate and impurity rate of the oat cleaner were 1.53% and 1.25%, respectively, under optimal conditions. Therefore, to improve the cleaning performance of the cleaner, it is necessary to theoretically analyze the phenomenon of airflow backflow in the cleaner, which can provide a reference for the follow-up design and optimization of the structure of the cleaner. Keywords: Airstream, Analysis, Cleaning, Particle image velocimetry, Test, Velocity field.

scholarly journals Experimental Validation of Falling Liquid Film Models: Velocity Assumption and Velocity Field Comparison

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1205
Author(s):  
Ruiqi Wang ◽  
Riqiang Duan ◽  
Haijun Jia
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Velocity Field ◽  
Experimental Validation ◽  
Particle Image ◽  
Velocity Fields ◽  
Number Range ◽  
Comparison Results ◽  
Image Velocimetry ◽  
Experimental Particle

This publication focuses on the experimental validation of film models by comparing constructed and experimental velocity fields based on model and elementary experimental data. The film experiment covers Kapitza numbers Ka = 278.8 and Ka = 4538.6, a Reynolds number range of 1.6–52, and disturbance frequencies of 0, 2, 5, and 7 Hz. Compared to previous publications, the applied methodology has boundary identification procedures that are more refined and provide additional adaptive particle image velocimetry (PIV) method access to synthetic particle images. The experimental method was validated with a comparison with experimental particle image velocimetry and planar laser induced fluorescence (PIV/PLIF) results, Nusselt’s theoretical prediction, and experimental particle tracking velocimetry (PTV) results of flat steady cases, and a good continuity equation reproduction of transient cases proves the method’s fidelity. The velocity fields are reconstructed based on different film flow model velocity profile assumptions such as experimental film thickness, flow rates, and their derivatives, providing a validation method of film model by comparison between reconstructed velocity experimental data and experimental velocity data. The comparison results show that the first-order weighted residual model (WRM) and regularized model (RM) are very similar, although they may fail to predict the velocity field in rapidly changing zones such as the front of the main hump and the first capillary wave troughs.

scholarly journals Aerodynamics of manoeuvring flight in brown long-eared bats ( Plecotus auritus )

2018 ◽  
Vol 15 (148) ◽  
pp. 20180441 ◽  
Author(s):  
Per Henningsson ◽  
Lasse Jakobsen ◽  
Anders Hedenström
Keyword(s):  
Particle Image Velocimetry ◽  
Wind Tunnel ◽  
High Speed ◽  
Particle Image ◽  
Future Studies ◽  
Image Velocimetry ◽  
Mechanistic Basis

In this study, we explicitly examine the aerodynamics of manoeuvring flight in animals. We studied brown long-eared bats flying in a wind tunnel while performing basic sideways manoeuvres. We used particle image velocimetry in combination with high-speed filming to link aerodynamics and kinematics to understand the mechanistic basis of manoeuvres. We predicted that the bats would primarily use the downstroke to generate the asymmetries for the manoeuvre since it has been shown previously that the majority of forces are generated during this phase of the wingbeat. We found instead that the bats more often used the upstroke than they used the downstroke for this. We also found that the bats used both drag/thrust-based and lift-based asymmetries to perform the manoeuvre and that they even frequently switch between these within the course of a manoeuvre. We conclude that the bats used three main modes: lift asymmetries during downstroke, thrust/drag asymmetries during downstroke and thrust/drag asymmetries during upstroke. For future studies, we hypothesize that lift asymmetries are used for fast turns and thrust/drag for slow turns and that the choice between up- and downstroke depends on the timing of when the bat needs to generate asymmetries.

scholarly journals Dual-camera system for high-speed imaging in particle image velocimetry

2012 ◽  
Vol 15 (3) ◽  
pp. 193-195 ◽  
Author(s):  
K. Hashimoto ◽  
A. Hori ◽  
T. Hara ◽  
S. Onogi ◽  
H. Mouri
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
High Speed Imaging ◽  
Camera System ◽  
Image Velocimetry
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