Transition from Laminar to Turbulence - Revision history

Bipush at 20:45, 7 May 2015

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 Earlier we noticed that there is a critical point where the transition to turbulence occurs. We can discuss this in terms of a critical Reynolds number. The exact critical Reynolds number depends on the substance, but generally,
 Re < 2000, laminar flow
-Re > 4000, turbulent flow
+'''Re < 2000, laminar flow'''

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 Now let’s take your answers to that question and write them in equation form. Remember that if you said that one factor needed to increase in order to increase the likelihood of turbulence, they are directly proportional. If a factor needed to decrease in order to increase the likelihood of turbulence, they are indirectly proportional. Remember that the way we write those types of relationships mathematically is like this:
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 cup glue
 (food coloring if desired)
 ½ cup hot water
 tsp. borax (find it in the laundry aisle)
 Step 1: Mix glue & ¾ cup water (and food coloring)
 Step 2: mix borax with ½ cup water until dissolved
 Step 3: pour borax mixture into glue mixture while mixing with hands
 Warning: Flubber will seep into fabric and carpet and there’s no easy way to get it out. Keep flubber stored in an air-tight container so that it doesn’t dry out.

@@ Line 113: / Line 113: @@
 Where
-'''Re = the Reynolds number
+'''Re = the Reynolds number'''
-ρ (Greek letter rho) = density
+'''v = velocity'''
-v = velocity
+'''L = length'''
-L = length
+'''μ = viscosity'''
 You’ll note that density has suddenly appeared; we did not discuss this earlier because differences in density tend to be smaller than differences in viscosity for different common fluids. One example where density is important is water v. air. Air is much less dense than water and is much easier to get to turbulent flow.

@@ Line 113: / Line 113: @@
 Where
 '''Re = the Reynolds number
 ρ (Greek letter rho) = density

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 Tada! You just developed the same equation that was introduced by Sir George Stokes and popularized by Osborne Reynolds! It is commonly written like this:
-[[File:Renoylds_number]]
+[[File:Renoylds_number.png]]
 Where