• Applied Chemistry for Engineering
• /
• v.28 no.4
• /
• pp.448-453
• /
• 2017

We conducted the three-dimensional fluid flow analysis in a Taylor reactor using computational fluid dynamics (CFD). The Taylor flow can be categorized into five regions according to Reynolds number, i.e., circular Couette flow (CCF), Taylor vortex flow (TVF), wavy vortex flow (WVF), modulated wavy vortex flow (MWVF), and turbulent Taylor vortex flow (TTVF), and we investigated the flow characteristics at each region. For each region, the shape, number and length of vortices were different and they influenced on the bypass flow. As a result, the Taylor vortex was found at TVF, WVF, MWVF and TTVF regions. The highest number of Taylor vortex was observed at TVF region, while the lowest at TTVF region. The numerical model was validated by comparing with the experimental data and the simulation results were in good agreement with the experimental data.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.40 no.1
• /
• pp.9-19
• /
• 2016

This study investigated the variations of Taylor flow and particle residence time in a Taylor reactor according to the changes of angular velocity and inlet velocity using computational fluid dynamics technique. The results showed that the fluid in a reactor became unstable with an increase of angular velocity. The flow moved to the regions of CCF, TVF, WVF and MWVF resulting in an increase of Reynolds number. Accordingly, the flow characteristics were different for each regions. We confirmed that the inlet velocity influences the Taylor flow. The particle residence time and standard deviation increased with an increase of angular velocity and a decrease of inlet velocity.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.329-332
• /
• 2002

A theoretical study is made of the steady flow of a compressible fluid in a rapidly rotating finite cylinder. Flow is generated by imposing mechanical and/or thermal disturbances at the rotating endwall disks. Both the Ekman and Rossby numbers are small. A detailed consideration is given to the energy budget for a control volume in the Ekman boundary layer. A combination of physical variables, which is termed the energy contents, consisting of temperature and modified angular momentum, emerges to be relevant. The distinguishing features of a compressible fluid, in contrast to those of an incompressible fluid, are noted. For the Taylor-Proudman column to be sustained, in the interior, it is shown that the net energy transport between the solid disk wall and the interior fluid should vanish. Physical rationalizations are facilitated by resorting to the concept of the afore-stated energy content.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.5
• /
• pp.268-273
• /
• 2017

In this study, nickel hydroxide crystalline powders were synthesized by continuous reaction in the taylor fluid flow using nickel chloride, nickel sulphate and sodium hydroxide as raw materials and compared with those prepared by a conventional batch type reaction. The crystallinity of nickel hydroxide prepared by the Taylor fluid flow reaction was higher than that of nickel hydroxide obtained by batch reaction. The particle size of nickel hydroxide decreased about 2.5 to 3.6 times, and the specific surface area was increased.

• Applied Chemistry for Engineering
• /
• v.26 no.1
• /
• pp.67-73
• /
• 2015

Using a computational fluid dynamics technique, the flow characteristics and particle residence time in a Taylor reactor were studied. Since flow characteristics in a Taylor reactor are dependent on the operating conditions, effects of the inlet flow velocity and reactor rotational speed were investigated. In addition, the particle residence time of $LiNiMnCoO_2$ (NMC), which is a cathode material in lithium-ion battery, is estimated in the Taylor vortex flow (TVF) region. Without considering the complex chemical reaction at the inlet, the effect of Taylor flow was studied. The results show that the particle residence time increases as the rotating speed increased and the flow rate decreased.

• The KSFM Journal of Fluid Machinery
• /
• v.2 no.1 s.2
• /
• pp.103-107
• /
• 1999

Transient flow inside a hollow shaft of a Gas Turbine engine during sudden engine stop may result in non uniform heat transfer coefficients in the shaft due to flow instability similar to steady Taylor vortex, which may decrease the lifetime of the shaft. In the present study, transient Taylor vortex phenomena inside a suddenly stopped hollow shaft are studied analytically. Flow visualization is also performed to study the shape and onset time of Taylor Vortices for various initial rotational speed.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.5
• /
• pp.697-704
• /
• 2001

The flow between two concentric cylinders, with the inner one rotating, is studied using numerical simulation. This study considers the identical flow geometry as in the experiments of Wereley and Lueptow[J. Fluid Mech., 364, 1998]. They carried out experiment using PIV to measure the velocity fields in a meridional plane of the annulus in detail. When Taylor number increases over the critical one, the flow instability caused by curved streamlines of the tangential flow induces Taylor vortices in the flow direction. As Taylor number further increases over another critical one, the steady Taylor vortices become unsteady and non-axisymmetrically wavy. The velocity vector fields obtained also show the same flow features found in the experiments of Wereley and Lueptow.

• Proceedings of the KSME Conference
• /
• 2001.06e
• /
• pp.27-32
• /
• 2001

A study has been made of the condition to maintaining Taylor-Proudman column flows in a compressible rotating fluid, which is driven by small mechanical and/or thermal perturbations imposing on the container wall in the basic state of isothermal rigid body rotation. The Rossby and system Ekman numbers are assumed to be very small. The Taylor-Proudman column flow can be produced when energy parameter, e, becomes constant on the whole flow region. Energy balance concept, related to energy parameter, and its physical interpretation are given with comprehensive discussions.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.5
• /
• pp.705-712
• /
• 2001

The flow between two concentric cylinders, with the inner one rotating and with an imposed pressure-driven axial flow, is studied using numerical simulation. The case without the axial flow was investigated in the preceding paper. This study considers the identical flow geometry as in the experiments of Wereley and Lueptow[Phys. Fluid, 11(12), 1999]. They carried out experiments using PIV to measure the velocity fields in a meridional plane of the annulus in detail. When an axial flow is imposed, the critical Taylor number is increased. The axial flow stabilizes the flow field and decreases the torque required to rotate the inner cylinder. The velocity vector fields obtained also show the same flow features found in the experiments of Wereley and Lueptow.

• Proceedings of the KSME Conference
• /
• 2001.06e
• /
• pp.444-449
• /
• 2001

The flow between two concentric cylinders, with the inner one rotating and with an imposed pressure-driven axial flow, is studied using numerical simulation. This study considers the identical flow geometry as in the experiments of Wereley and Lueptow[Phys. Fluid, 11 (12), 1999]. They carried out experiments using PIV to measure the velocity fields in a meridional plane of the annulus in detail. When an axial flow is imposed, the critical Taylor number is increased. The axial flow stabilizes the flow field and decreases the torque required to rotate the inner cylinder. The velocity vector fields obtained also show the same flow features found in the experiments of Wereley and Lueptow.