difference between air flow and velocity
Air velocity can be measured by sensing the pressure produced by the movement of the air. This application note will describe the basic relationships between air velocity and the pressure generated by air flow. Anyone who has put their hand out the window of a moving car has experienced the force applied by moving air.
1. Air Flow. Flow of air or any other fluid is caused by a pressure differential between two points. Flow will originate from an area of high energy, or pressure, and proceed to area(s) of lower energy or pressure.