I'm currently doing a project in my tech class where a partner and I have to create a wind turbine. We've decided that we are creating a vertical axis wind turbine, that we are creating the base out of PVC, and using three airfoil shaped blades that will be created via cnc milling. I have a few questions about the blade design process. It seems that airfoil blades are the most effective for what we are doing with the resources that we have. How exactly does an airfoil work? I've heard that the common explanation that the wind moving across the top of the blade must move faster causing a pressure difference is incomplete. Also, how should we go about figuring out the exact shape of the blade? Finally, how exactly is wind created? As I understand it, the earth is unevenly heated causing pressure differences that result in wind, but why exactly is it that the earth is heated unevenly?