Paying attention to your phone instead of your surroundings is dangerous, especially while driving. PHYSICAL CHEMISTRY WITH APPLICATIONS TO BIOLOGICAL SYSTEMS. 2nd edition, Edition en anglais PDF are some creative and original answers: The chicken crossed the road.
But why did the chicken cross the road? How To Tie A Tie: 8 Knots Every Man Should Master « , »content_video »:null, »content_etag »:null, »content_slug »:null, »avatar_id »:null, »avatar_name »: »Joe Nobody », »category_title »: »Fashionbeans. The plume from this candle flame goes from laminar to turbulent. The Reynolds number can be used to predict where this transition will take place. A vortex street around a cylinder.
This can occur around cylinders and spheres, for any fluid, cylinder size and fluid speed, provided that it has a Reynolds number between roughly 40 and 1000. Sir George Stokes introduced Reynolds numbers. Reynolds number is the ratio of inertial forces to viscous forces within a fluid which is subjected to relative internal movement due to different fluid velocities, which is known as a boundary layer in the case of a bounding surface such as the interior of a pipe. This ability to predict the onset of turbulent flow is an important design tool for equipment such as piping systems or aircraft wings, but the Reynolds number is also used in scaling of fluid dynamics problems, and is used to determine dynamic similitude between two different cases of fluid flow, such as between a model aircraft, and its full size version. Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies, vortices and other flow instabilities. The Reynolds number can be defined for several different situations where a fluid is in relative motion to a surface.
In practice, matching the Reynolds number is not on its own sufficient to guarantee similitude. Fluid flow is generally chaotic, and very small changes to shape and surface roughness can result in very different flows. Nevertheless, Reynolds numbers are a very important guide and are widely used. Osborne Reynolds’ apparatus of 1883 demonstrating the onset of turbulent flow.
The apparatus is still at the University of Manchester. Diagram from Reynolds’ 1883 paper showing onset of turbulent flow. Osborne Reynolds famously studied the conditions in which the flow of fluid in pipes transitioned from laminar flow to turbulent flow. The larger pipe was glass so the behaviour of the layer of the dyed stream could be observed, and at the end of this pipe there was a flow control valve used to vary the water velocity inside the tube. When the velocity was low, the dyed layer remained distinct through the entire length of the large tube. When the velocity was increased, the layer broke up at a given point and diffused throughout the fluid’s cross-section. From these experiments came the dimensionless Reynolds number for dynamic similarity—the ratio of inertial forces to viscous forces.