Péclet number (Pe) - Nishanth Saldanha: Difference between revisions

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== Applications to Microfluidics ==
== Applications to Microfluidics ==


[[Image:Tsensor.jpeg|150px|right|thumbnail|'''Figure 2''' Diffusion dominated mixing that occurs in a T-sensor makes it useful in florescence based analytical tests. The analyte (in blue) diffuses with the species in the channel as a function of the length of the middle channel. <sup>[5]</sup>]
[[Image:Tsensor.jpeg|150px|right|thumbnail|'''Figure 2''' Diffusion dominated mixing that occurs in a T-sensor makes it useful in florescence based analytical tests. The analyte (in blue) diffuses with the species in the channel as a function of the length of the middle channel. <sup>[5]</sup>]]


[[Image:Hfilter.jpg|150px|right|thumbnail|'''Figure 3''' This is a microfluidic device that allows convenient extraction of small molecules from complex fluids into simpler buffer streams <sup>[6]</sup>]
[[Image:Hfilter.jpg|150px|right|thumbnail|'''Figure 3''' This is a microfluidic device that allows convenient extraction of small molecules from complex fluids into simpler buffer streams <sup>[6]</sup>]]


[[Image:Herringbonemixer.jpg|150px|right|thumbnail|'''Figure 4''' Diagrams showing performance of staggered herringbone mixer. Image by MIT OpenCourseWare. Adapted from Figure 3 on p. 64 in Stroock et al. <sup>[[7]]</sup>
[[Image:Herringbonemixer.jpg|150px|right|thumbnail|'''Figure 4''' Diagrams showing performance of staggered herringbone mixer. Image by MIT OpenCourseWare. Adapted from Figure 3 on p. 64 in Stroock et al. <sup>[7]</sup>]]


The low inertial forces present within many microfluidic setups, due to low velocity and length scales, often yield low Reynolds number flows <sup>[4]</sup>: low levels of turbulence can also be expected in these flow regimes. Thus convection is not prevalent in microfluidic setups, unless they are purposely induced. Most mixing that do occur in these devices occur due to diffusion [4]. Diffusion induced mixing is much slower than convective mixing, with mixing times in different order of magnitude. [4]
The low inertial forces present within many microfluidic setups, due to low velocity and length scales, often yield low Reynolds number flows <sup>[4]</sup>: low levels of turbulence can also be expected in these flow regimes. Thus convection is not prevalent in microfluidic setups, unless they are purposely induced. Most mixing that do occur in these devices occur due to diffusion [4]. Diffusion induced mixing is much slower than convective mixing, with mixing times in different order of magnitude. [4]

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