521 ADV FLUID MECH II  
Winter 2003

                  
Hwk 5 (Due Apr 15)

1. Modify the Prandtl mixing length theory to have fewer restrictions, such as
    a) allow variable t
    b) include molecular viscosity
    c) have smooth value of eddy size l at centerline
and compare to standard Prandtl and von Karman profiles.

2. Perform and explain some simple turbulent experiments with blowing out a candle.
    a) Find if and when placing a finger in front of the flame makes it easier to extinguish.
    b) Roll up a paper tube and place it around your mouth and blow through it. Does this help? Now place the tube several inches from your mouth. Better? What is the optimal geometry of mouth, tube, candle?