Hello, I read about airfoil mechanism that there happens to be pressure difference created above and below the airfoil which result in lift force. My questions are: 1. What actually happens in the speed of air. I mean how can one side of the air travels with greater speed when they have the same speed in the beginning? And how this whole process happens. 2. What is drag force and how is it created. 3. How is angle of lift help in vawt? If I want to start from the beginning to study and go deep into this topic guide me in right direction. Also help me with online materials available. I would like to stretch my all time into this project. Just needed a perfect direction to work.