scholarly journals Numerical Simulation of Non-Spherical Submicron Particle Acceleration and Focusing in a Converging–Diverging Micronozzle

2021 ◽  
Vol 12 (1) ◽  
pp. 343
Author(s):  
Yanru Wang ◽  
Jiaxin Shen ◽  
Zhaoqin Yin ◽  
Fubing Bao
Keyword(s):  
Numerical Simulation ◽  
Particle Acceleration ◽  
Flow Field ◽  
Shape Factor ◽  
Particle Density ◽  
Submicron Particles ◽  
Submicron Particle ◽  
Shape Factors ◽  
Focusing Effect ◽  
Aerodynamic Focusing

Submicron particles transported by a Laval-type micronozzle are widely used in micro- and nano-electromechanical systems for the aerodynamic scheme of particle acceleration and focusing. In this paper, the Euler–Lagrangian method is utilized to numerically study non-spherical submicron particle diffusion in a converging–diverging micronozzle flow field. The influence of particle density and shape factor on the focusing process is discussed. The numerical simulation shows how submicron particle transporting with varying shape factors and particle density results in different particle velocities, trajectories and focusing in a micronozzle flow field. The particle with a larger shape factor or larger density exhibits a stronger aerodynamic focusing effect in a supersonic flow field through the nozzle. In the intersection process, as the particle size increases, the position of the particle trajectory intersection moves towards the throat at first and then it moves towards the nozzle outlet. Moreover, the influence of the thermophoretic force of the submicron particle on the aerodynamic focusing can be ignored. The results will be beneficial in technological applications, such as micro-thrusters, microfabrication and micro cold spray.

Numerical Simulation of Flow Field Characteristics of Free Falling Particle Plume Affected by Particle Diameter and Density

2014 ◽  
Vol 894 ◽  
pp. 163-166 ◽  
Author(s):  
Ze Qin Liu ◽  
Ling Yu Liu ◽  
Xiao Jian Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Particle Density ◽  
Fluid Dynamic ◽  
Particle Diameter ◽  
Ambient Air ◽  
Two Phase ◽  
Flow Field Characteristics ◽  
Computational Fluid Dynamic Software ◽  
Free Falling

The study of flow field characteristics of free falling particle plume is part of the basic application research of gas-solid two phase flow. The Computational Fluid Dynamic Software FLUENT was adopted in this paper. The numerical simulation was carried out to study the influence of particle diameter and particle density to the particle flow field characteristics of free falling particle plume. The results of the numerical simulation showed that, with the increasing of particle diameter and the increasing of particle density, the disturbance of ambient air to the particle plume decreased, and the entrainment ability of particle plume to the ambient air was diminished.

Study on wind load shape factor of long-span stadium roof

2020 ◽  
Vol 23 (11) ◽  
pp. 2333-2342
Author(s):  
Jian Guo ◽  
Minjun Zhu ◽  
Chengjie Hu
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Shape Factor ◽  
Wind Load ◽  
Design Stage ◽  
Bottom Surface ◽  
Shape Factors ◽  
Maximum Wind ◽  
Long Span ◽  
Load Shape

A long-span stadium roof has always been a wind load sensitive system, given its usual complex curved surface. However, there is no definite method for calculating the wind load shape factor of the complex building in the code. Based on this, the standard [Formula: see text] model was applied to the computational fluid dynamics numerical simulation of a long-span stadium roof at the wind attack angles of 0°–180°. The pressure distribution on the top and bottom surfaces of the stadium roof and the wind load shape factor were obtained by numerical simulation. The results show that the negative pressure was dominant on the top surface of the roof and the positive pressure was dominant on the bottom surface of the stadium at the wind attack angle of 0°. The ring-shaped curtain wall made the wind field environment more complicated, mainly under the wind attack angles of 45° and 180°. Because of the dip angles at both ends of the roof, the wind pressure distribution at both ends of the roof was opposite to the main region. The maximum wind load shape factors of each region were negative. In addition, the maximum wind load shape factor was at 45°, which was −1.1. The maximum wind load shape factors in regions of R13–R19 were larger, which should be paid attention in design stage. In general, the wind load shape factors were large in the central region and small at both ends. The wind load shape factors of the roof were bounded by 90°, showing an anti-symmetric trend.

Focusing of inertial particles after the shock-wave intersection point

2007 ◽  
Vol 5 ◽  
pp. 145-150
Author(s):  
I.V. Golubkina
Keyword(s):  
Shock Wave ◽  
Mass Concentration ◽  
Gas Flow ◽  
Intersection Point ◽  
Plane Shock ◽  
Inertial Particles ◽  
Dusty Gas ◽  
Focusing Effect ◽  
Aerodynamic Focusing ◽  
Particle Mass Concentration

The effect of the aerodynamic focusing of inertial particles is investigated in both symmetric and non-symmetric cases of interaction of two plane shock waves in the stationary dusty-gas flow. The particle mass concentration is assumed to be small. Particle trajectories and concentration are calculated numerically with the full Lagrangian approach. A parametric study of the flow is performed in order to find the values of the governing parameters corresponding to the maximum focusing effect.

scholarly journals Numerical Simulation of Characteristics of Spray Flow Field on the Conical Surface

2020 ◽  
Vol 1670 ◽  
pp. 012030
Author(s):  
Shiming Chen ◽  
GuichunYang ◽  
Shuang Zhou ◽  
Wenzhuo Chen ◽  
Jinfa Guan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Conical Surface

scholarly journals Influence of Vortex Finder Structure on Separation Performance of Double-Overflow Three-Product Hydrocyclones

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 79
Author(s):  
Yuekan Zhang ◽  
Jiangbo Ge ◽  
Lanyue Jiang ◽  
Hui Wang ◽  
Junru Yang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Experimental Research ◽  
Separation Efficiency ◽  
Structural Parameters ◽  
Separation Performance ◽  
Insertion Depth ◽  
Flow Field Characteristics ◽  
Vortex Finder ◽  
Fine Classification

In view of the difficulty of traditional hydrocyclones to meet the requirements of fine classification, a double-overflow three-product (internal overflow, external overflow and underflow) hydrocyclone was designed in this study. Numerical simulation and experimental research methods were used to investigate the effects of double-overflow flow field characteristics and structural parameters (i.e., internal vortex finder diameter and insertion depth) on separation performance. The research results showed that the larger the diameter of the internal vortex finder, the greater the overflow yield and the larger the cut size. The finest internal overflow product can be obtained when the internal vortex finder is 30 mm longer than the external vortex finder. The separation efficiency is highest when the internal vortex finder is 30 mm shorter than the external vortex finder.

Sign in / Sign up

Export Citation Format

Share Document