Birth of an LCTR®
A Taylor fluid flow is a flow that was found by Couette in early 1900s to be used as a viscometer and was analyzed via a formula by Taylor in mid 1900s. The Taylor fluid flow was used for a heat exchanger due to its very high mass transfer speed, and was commercialized for a chemical product production reactor by our company.
Taylor fluid flow?
A reactor using a Taylor fluid flow is composed of two cylinders, in which a round bar-type cylinder is inserted into a pipe-type cylinder. This shows a unique flow characteristic as the outer cylinder is fixed and the inner cylinder rotates.
The fluid flows in the rotating direction as the inner cylinder rotates, but there occurs a force for the fluids on the inner cylinder to go to the outer cylinder direction via a centrifugal force and a Coriolis force, so the fluid flow becomes gradually unstable as the rotation speed increases to create vortexes of ring pair array rotating regularly and in the counter directions along the axial direction, which are called a Taylor flow.
Principle of Creation of a Taylor Fluid Flow
A Taylor fluid flow can generate a turbulent flow easily by changing the rotational speed of an inner cylinder, so it is much used to study the stability of a fluid. Rayleigh performed a stability analysis for a non-viscous fluid for the first time.
For a viscous fluid, Taylor reported that a Taylor vortex occurs in a domain larger than the critical Taylor number based on linear theory. The instability condition of a flow can be represented as a Taylor number(Ta), which is defined by a rotational direction Reynolds number and a reactor shape factor(d/R1) as follows;
where d is the distance between two cylinders, R1 is the radius of the inner cylinder, ω1 is the rotational angular speed of the inner cylinder, and ν is the dynamic viscosity of the fluid.
Taylor presented that the critical Taylor number(Tac) as d/R1 approaches 0 is 41.3, and Kataoka et al. classified the flow characteristics based on a Taylor number when d/R1 is 0.62 without axial flow as follows;
- Ta < Tac : laminar flow
- Tac < Ta < 800 : laminar vortex(single periodic) flow
- 800c < Tac < 2000 : laminar vortex(double periodic) flow
- 2000c < Tac < 10000~15000 : turbulent vortex flow
- Tac > 15000 : turbulent flow
Research on Fluid Flow
|Taylor Fluid Flow
|Number of annulus(ea)