Engineering Riddle – No. 5 (Fluid Mechanics) “Dimensionless”
I’m a fraction made of forces, comparing different strength
I have no final units, only characteristic length
I sample speed and weight and size, these are the things I measure
My subject as it ebbs and flows, changes shape forever
On top I show inertia, the power to keep things steady
Below I measure thickness, stickiness and eddy
In pipe or duct or channel, o’er wings be smooth, or rough
I’ll tell you dominant motive, whether sheering’s weak or tough
What am I?
In the study of fluid mechanics, the Reynolds Number is used to understand and predict the type of fluid flow in various situations. Here is a more detailed explanation.
http://en.wikipedia.org/wiki/Reynolds_number
What is the Reynolds Number?