The propeller blades are curved on one side and flat on the other to achieve what?

The design of propeller blades, featuring a curved side and a flat side, is primarily intended to produce thrust. When the propeller rotates, the blades generate a difference in air pressure on either side due to their shape. The curved side, which is the airfoil, moves faster through the air than the flat side. This speed differential results in lower pressure on the curved side and higher pressure on the flat side, creating lift in the forward direction. This phenomenon is crucial for propeller operation, as it effectively pushes the aircraft forward by converting rotational motion into linear thrust. The specific curvature, referred to as the airfoil shape, is essential for optimizing the amount of thrust generated while ensuring efficient performance across various speeds and operating conditions.