Granular Dynamics in a Vertical Bladed Mixer: Secondary Flow Patterns.

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985858%3A_____%2F19%3A00497842" target="_blank" >RIV/67985858:_____/19:00497842 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60461373:22340/19:43918365 RIV/44555601:13430/19:43895283 RIV/44555601:13440/19:43895283

Výsledek na webu

<a href="http://hdl.handle.net/11104/0294052" target="_blank" >http://hdl.handle.net/11104/0294052</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.powtec.2018.11.094" target="_blank" >10.1016/j.powtec.2018.11.094</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Granular Dynamics in a Vertical Bladed Mixer: Secondary Flow Patterns.

Popis výsledku v původním jazyce

This article deals with numerical simulations and experimental measurements of the granular mixing process in a vertical cylindrical mixer with two opposed flat blades with a 45° rake angle. The computer simulations were conducted via discrete element method. The experimental measurements were recorded by a color high-speed camera. Both approaches describe the mixing process in the same way with significant agreement in observations. Even though the geometry and operating conditions are simple, the dynamics of the system is often very complex and a variety of flow structures can be created. For that reason, the behavior of individual flows patterns was analyzed and discussed. The effect of the centrifugal force on deformation of the free level of the granular material and the formation of empty spaces behind the stirrer blades was described. In addition, the behavior of individual particles in specific regions was characterized. At low rotational speed of the blades, particles tend to move close to the bottom of the vessel behind the stirrer blade towards the shaft. At high values, particles are moving in the exact opposite direction. Described movements near the base of the vessel create secondary flow in the form of recirculation zones. Presence of the secondary flow during the mixing process was also confirmed by the experimental measurements. Based on the acquired knowledge, two competing mechanisms of secondary flow formation were presented: (i) the different contact time of the particles with the blade, (ii) the different magnitude of inertial forces acting on the particles around the stirrer blade.

Název v anglickém jazyce

Granular Dynamics in a Vertical Bladed Mixer: Secondary Flow Patterns.

Popis výsledku anglicky

This article deals with numerical simulations and experimental measurements of the granular mixing process in a vertical cylindrical mixer with two opposed flat blades with a 45° rake angle. The computer simulations were conducted via discrete element method. The experimental measurements were recorded by a color high-speed camera. Both approaches describe the mixing process in the same way with significant agreement in observations. Even though the geometry and operating conditions are simple, the dynamics of the system is often very complex and a variety of flow structures can be created. For that reason, the behavior of individual flows patterns was analyzed and discussed. The effect of the centrifugal force on deformation of the free level of the granular material and the formation of empty spaces behind the stirrer blades was described. In addition, the behavior of individual particles in specific regions was characterized. At low rotational speed of the blades, particles tend to move close to the bottom of the vessel behind the stirrer blade towards the shaft. At high values, particles are moving in the exact opposite direction. Described movements near the base of the vessel create secondary flow in the form of recirculation zones. Presence of the secondary flow during the mixing process was also confirmed by the experimental measurements. Based on the acquired knowledge, two competing mechanisms of secondary flow formation were presented: (i) the different contact time of the particles with the blade, (ii) the different magnitude of inertial forces acting on the particles around the stirrer blade.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20402 - Chemical process engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Powder Technology

ISSN

0032-5910

e-ISSN

—

Svazek periodika

344

Číslo periodika v rámci svazku

FEB 15

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

79-88

Kód UT WoS článku

000461262200009

EID výsledku v databázi Scopus

2-s2.0-85057626636