Today is the Longest Day of the Year (Photos of the Midnight Sun) June 21 gets the prize as the longest day of the year 2013 in Iceland. Whatâs more, summer seems to be arriving in ReykjavÃ­k. Last night people were waiting to see the midnight sun set, well at midnight in ReykjavÃ­k. The air was calm and clean and so were the people who sat on the shore.
Definition of airfoil. : a body (such as an airplane wing or propeller blade) designed to provide a desired reaction force when in motion relative to the surrounding air.
We can also think of drag as aerodynamic resistance to the motion of the object through the fluid. This source of drag depends on the shape of the aircraft and is called form drag. As air flows around a body, the local velocity and pressure are changed.rag is the aerodynamic force that opposes an aircraft's motion through the air. Drag is generated by every part of the airplane (even the engines!