Laminar Flow Realization Of TC Flow Between Two Concentric Cylinders And Analysis Of Related Phenomena In Experiments

The flow between rotating concentric cylinders is called Taylor-Couette(TC)flow,which is one of the simplest curved flows.G.I.Taylor conducted a detailed study on this as early as 1923;after him,many scholars studied the stability of this flowing fluid,but few people studied the laminar flow pattern in detail.Prof.Zou Wennan proposed to use spin and bending torsion fields to describe the small-scale vortex motion and large-scale vortex structure in turbulent flow through the discussion of the mechanism of fluid viscosity.,Established a set of flow theories that are richer than the classical theory.The new theory and the classic Navier-Stokes equation theory in TC flow will give different predictions of the circumferential velocity distribution.In view of this,the research goal of this paper is the laminar flow velocity distribution of the fluid between the cylinders when the concentric cylinders move at the same low speed,and the experimental verification is carried out by designing a high-precision experimental platform.The results are as follows:(1)When the inner and outer cylinders rotate at the same angular velocity,the classical theory gives that the fluid between the cylinders is rotated by a rigid body,and the viscous force between the cylinders is zero everywhere;but the new theory shows that there is a viscous force between the inner and outer cylinders,and the internal fluid will have a higher rotation speed than the nearby fluid,which is obviously different from the same everywhere in the classical theory.The experimental results show that the measured speed in the middle of the tube will be slightly greater than the rotational speed of the rigid body,which is usually interpreted as an end effect or an experimental error.The analytical curve of the new theory just fits it.(2)The measurement is performed using a single frame long exposure method.The results of stationary shooting show that there is a small error between the movement speed of the tracer particles between the cylinders and the classical and new theories,but the movement speed of the fluid near the inner and outer wall surfaces is more consistent with the new theory.Approaching,while the fluid velocity of the middle part fluctuates.(3)The results of motion photography show that the fluid motion near the inner and outer wall surfaces is relatively stable.Vortex structure appears in the middle fluid.This also explains why only the fluid velocity at both ends fits well and the central part fluctuates during still shooting.Although the above results did not achieve the ideal goal,but could provide valuable reference for further experimental research.This article describes in detail our exploration of experimental research on the mechanism of fluid viscosity.The experimental platform designed in this paper will become the basis for subsequent experimental research.For this purpose,detailed information will be given,as well as some precautions and suggestions.