sentences:  The main fan on a jet engine consists of a number of aerofoils mounted at the rotational center on the fan disk, and as the engine core rotates the fan blades accelerate an air mass and create the force to move forward which gives thrust (in accordance with Newton's Third Law).In theory the larger the fan diameter (the line from the tip of one fanblade to its opposite member) the greater the thrust.In practical applications, fan size is limited by the weight, the space available around the aircraft and by the increased drag (resistance) generated by the larger frontal area.