Sankey Diagrams

What is a Sankey Diagram

A Sankey diagram is a graphic illustration of flows, like energy, material or money flows. Usually the flows are illustrated as arrows. The width of the arrows is proportional to the size of the represented flow. Sankey diagrams are a better way to illustrate which flows represent advantages and what flows are responsible for waste and emissions.

Definition provided by STENUM GmbH

The Sankey Diagram and Work

When working with Sankey diagrams and physics, most physics Sankey diagram are use to examine energy efficincy.  But when using the idea of work consider the Input energy to Input work (it turns out to be the exact same thing units and all) and the useful output energy to output work.  This "conversion" hold true the principal of work, energy and the Sankey diagram. 

How to draw a Sankey Diagram

     A Sankey diagram illustrates an input/output situation. It is drawn to scale - there are lots of variations as to how they are drawn - only thing they have in common is that the width of the 'arms' represents the energy transferred but the length of the 'arms' does not! 

Sankey diagrams allow us to visualize flow through a process or system more easily that numerical data can. They show not only the order of changes but also the quantitative distribution of values in the transfers.

Sankey diagrams do add an indisputable expressive power to mathematical rendering of a system. When professionally constructed, Sankey diagrams represent flow in a manner that can be understood by anyone, instantly.

However, Sankey diagrams can be difficult, time-consuming, and uninteresting to produce by hand - very tedious to draw! The benefits of being able to generate these diagrams automatically, anytime, are obvious to anyone who has tried to draw one and commercial computer packages for their production are available. They are used not only in physics and engineering to demonstate how energy is distributed but also for cash flow in businesses.

Explanation and diagrams provided by Cyberphysics