Interlacing creates angles and pushing movement of the impeller to force two streams of laminar motion to collide into one another. In high viscosity mixing, you must have a mixer that moves your substances at a high intensity with a high degree of interlacing as well. When it comes to viscous flow, how does one bring the same uniformity and homogeneity you would find in a turbulent system to the laminar system? The insights you discover here will help you choose the right type of high viscosity mixer depending on the application that you need it for. These conditions lead to a better mix and a more uniform structure, however the challenge of high viscosity mixing is creating this chaotic turbulence by relying on the pushing structures of impellers rather than then left over momentum from the last push of the impeller. These flows will eventually move into each other and form new eddies this is where chaotic turbulence comes from. Turbulent flow is usually defined by the relationship between the fluid velocity and a point in a related eddy, a sizing that can fluctuate according to the turbulence type. Below 2,000, flow is more streamlined (hence this area being call Laminar), Many of the predictive empirically derived equations break down in this zone. This boundary is highly debated, and has led to this area being characterized as the “transitional” zone. A traditional boundary between laminar and turbulent flow is usually around2,000. A typical range of turbulent flow as measured by the Reynolds number is from 20,000 and above. Once you have a Reynolds number measurement for a flow, you can determine the character of the eddy currents that form. One of the main uses of the Reynolds number is to differentiate between the stable laminar and turbulent flows. It is a dimensionless measurement that is created from the viscosity, the density and the flow velocity of the substances in the turbine. The Reynolds number is a quantifier that is used to measure turbulence. The main symptom for this kind of turbulence is that it has no rotation (vorticity). Isotropic turbulence is the rare case in which the root, mean and square fluctuating velocity measurements are the same. It is measured by comparing the fluctuating velocity against the mean velocity. The higher the viscosity, the less turbulent the flow.įlow is described in terms of the intensity it creates. Low viscosity mixes have a higher turbulence and extended flow. The movement of the faces of the blades in the mixer is significant and can range from 2 to 10 times the diameter of the blades. Under 5,000 centipoise, the flow that comes from mixing is considered chaotic. Turbulent flow is normally what one tries to achieve inside a standard turbine-type mixer. Laminar Flow, Transitional Flow, and Turbulent flow. There are three types of flow that can be achieved in a certain volume of fluid. In order to understand the fundamentals of high viscosity mixing (high viscosity or otherwise), it is important to understand the nature of flow as characterized by the Reynolds number. This goal is readily achieved in thinner, waterlike substances, however, highly viscous materials do not easily achieve this type of uniformity, and requires detailed understanding of the rheologies and agitation forces involved. The ideal result of mixing is a uniform, completely homogeneous solution. The simplest way to think of mixing is the process of fusing ingredients that are otherwise separate and independent through an external force.
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